New advanced high performance renderer for 3ds Max and Cinema 4D, and (soon) other platforms.
Corona Renderer delivers high quality, physically-based shading in production rendering. All its features are tightly integrated into Autodesk 3ds Max and Cinema 4D.
Please see the Updates section for more on the major new features in v4 for 3ds Max.
Please see the Updates section for more on the major new features in v3.
Corona Renderer delivers predictable, reliable, and physically plausible results with no compromises in quality. Realistic lighting and materials are yours right out of the box…
Biased and Unbiased Rendering
Corona Renderer offers both biased and unbiased rendering solutions.
By default, Corona Renderer uses a slightly biased solution, very close to being unbiased but considerably reducing render times. This is the recommended solution and works without you having to do any setup whatsoever. Corona Renderer will always deliver crisp, realistic results without splotches, interpolation artifacts or any other visual imperfections.
Although most users never need it, the option does exist to choose to render in a fully unbiased mode using advanced rendering algorithms like BDPT/VCM. These algorithms can enhance certain specific features in rendering, such as caustics, but with the associated performance penalty.
Traditionally, you had to choose between using unbiased algorithms with no caching and accept long render times, or using biased caching algorithms and deal with splotches, missing shadows, and sensitive input parameters. Corona Renderer merges the best of both worlds – the UHD cache is significantly faster than plain path tracing, but does not suffer from artifacts, missing contact shadows, or complicated UI controls.
The UHD cache uses only partial caching, so does not try to interpolate everything. While this is slower than a fully cached solution (such as irradiance caching), it does not create artifacts, only the noise that eventually goes away.
The UHD cache is an ideal solution for animation and significantly reduces flickering even when light sources or geometry are moving. This is especially important when the cache cannot be precomputed.
Ease Of Use
No–one calls themselves a “3D Technician” – everyone rightly calls themselves a 3D artist, and that means your tools should be as close to invisible as possible so they don’t get in the way of your creativity.
Corona Renderer is one of the easiest to learn render engines. Its setup really is as simple as pressing “Render”! Most new users will learn Corona Renderer in just one day, and fall in love with it over the next few.
Easy to Understand
Our mission with Corona Renderer is to liberate users from the technical, unnatural process that rendering was in the past. We are constantly trying to simplify the creative process by removing or hiding any unnecessary technical settings, so artists can focus on their vision. The era of studying manuals and sampling tweaking is over. Just press render and let Corona do its magic.
Corona Renderer is developed in tight cooperation with the artist community. Its creators are former artists as well, so this collective knowledge and experience play a huge role in the design and ongoing development.
Whether you are looking to purchase your first third-party renderer, or you are already a pro who has used many different engines, you’ll find Corona Renderer’s ease of use to be refreshing!
Use the Tools you Like
Corona Renderer is compatible with a huge range of third-party plugins, so you can continue to use any tools you already have integrated into your workflow – whether you are using Corona’s Interactive Rendering or doing a final render, you can keep right on using iToo’s Forest Pack and RailClone, Siger Shaders, Quixel Megascans, Allegorithmic Substance, Phoenix FD, FumeFX, Ornatrix, Hair Farm, and many more.
Corona Renderer is also compatible with the core V–Ray Materials and V–Ray Lights, which allows you to render those using Corona even if V–Ray is not installed. This is ideal for downloading V–Ray assets from model stores, or if you already have a library of assets in V–Ray format, or if you are studio using both engines, and so on.
Whether this is your first time adding a new renderer, or you are already a pro who has used many different engines, you’ll find Corona Renderer’s ease of use to be refreshing!
Speed & Interactivity
Speed is an important factor in any production environment, and a renderer must always deliver results as fast as possible.
As a result, we are obsessed with speed! We like to hunt for milliseconds in our own code and are always looking for ways to cut down parsing and rendering times without forcing users to buy expensive hardware, by focusing on creating smart algorithms under the hood. In every version we release, we look to boost the speed of rendering as much as possible as well as adding new features.
Corona Renderer uses Intel Embree Ray Tracing Kernels, making the CPU–only Corona as fast as many GPU renderers but without any of the limitations of GPU–based solutions…
The denoising feature analyzes noise in the 3D space, so is not just a 2D post–process. You can use it to reduce the number of passes needed to get a noise-free image, with render time reductions of 50 to 70% reported to us by third parties in commercial usage (not in carefully crafted test scenes!). It will also remove fireflies (hot pixels) from an image, and can be used only in that mode if required.
Denoising is seamlessly integrated into the core as a one-click solution. The denoising level can be interactively adjusted in the VFB after rendering is complete so that you are not locked into the level set in the rendering options. This lets you check and adjust the blending between the regular and the denoised image without having to re-render. You can also calculate Denoising in the Corona Image Editor rather than at render time and without the overhead of working in a 3D application.
Corona Renderer aims to make you faster as well as your renders, with a workflow that is second–to–none. Thanks to its fully–featured Interactive Rendering, Corona Renderer brings you all the same advantages as a GPU render engine but without any of the drawbacks and limitations.
You can change materials, lights, and create or adjust geometry and see your interactive render respond almost immediately. It runs completely on the CPU, so it has no limitations and won’t care what graphics card you have installed.
NVIDIA GPU Denoising
The NVIDIA OptiX denoiser lets you denoise your interactive renders, giving you a noise–free image in record time. You aren’t limited to using it only for interactive rendering however – you can also use the GPU denoiser for final renders too if you choose.
Note that this denoiser requires a compatible NVIDIA graphics card. Standard denoising uses the CPU only so can be used with any graphics card.
What You See Is What You Get
Our interactive rendering is an integral part of the Corona core and shares over 99.9% of the regular renderer code. This means that all features of Corona Renderer are supported, and that the results are exactly the same as your final render – you can render motion blur, DOF, create proxies, scatter systems and more, all with instant feedback.
Because our interactive and regular renderer is almost identical, all types of geometry and proxies are supported. The same goes for all the 3ds Max maps and third party maps. Even the advanced third-party plugins, such as Itoo Forest Pack, or hair and fur from Ornatrix, and Hair Farm, work as expected. You can find a full list of supported plugins in the Resources section.
Interactive Rendering also offers as many render regions as you like, which can be moved and resized as you choose. This means that so that they can act as a “sample brush”, letting you paint–in areas which you want to refine faster or inspect at better quality.
If you want to know more about the differences between CPU and GPU solutions, you can see here why we are proudly CPU based.
Efficient Handling of Many Lights
Corona handles scenes with many lights without problems and with no penalty to render time, so that you don’t have to worry about trying to optimize your scene.
Adaptive Image Sampling
This balances out the rendering calculations over the image to focus more processing power on tricky areas like shadows. By keeping noise more evenly distributed, this gives a usable image more quickly, and also allows Denoising to work its magic.
Powerful Workflow Tools
As former CG artists, we know that the output quality and speed are not the only things that make a great renderer. That is why Corona Renderer comes with many powerful tools to accelerate your workflow that will make you faster as well as your renders!
Extensive Post–Processing, Inside the VFB
Save time (and money) by reducing or even removing the need to use third–party software to carry out post-production work on your renders, thanks to the extensive range of post-processing tools available directly inside the Corona VFB. All of these can be adjusted before, during or after rendering, and settings saved for instant reuse in any scene.
Take a look at how much control you have over your final render with the list of effects below:
Exposure – Controls the overall exposure of the image.
Highlight Compression – Compresses highlights in the image to reduce/remove burned–out areas.
White Balance – Controls the white balance of the image.
Contrast – Adjust the contrast of the image.
Saturation – Controls the overall color saturation.
Filmic highlights – Controls a subtle highlight compression without loss of color saturation.
Filmic shadows – Controls the richness/saturation of shadows in the image.
Vignette intensity – Applies a subtle, realistic vignette.
Color tint – Adjust the overall color tint of the image.
LUTs – Allows quickly changing the overall look of the image by applying one of many ready-made LUTs. The strength of the LUT effect can be controlled using the LUT Opacity so that it is not “all or nothing”. A variety of LUTs are provided along with Corona.
Bloom & Glare – Bloom is a large, soft glow around bright areas in the image, while Glare is a small, sharp glow with adjustable rays around bright areas. The color of these effects can be adjusted using the Color Intensity and Color Shift parameters.
Sharpening/Blurring – This first blurs an image and then sharpens it, useful to remove “pixel–perfect” noise and give a more photographic look to the final image.
Denoising – If Denoising was enabled, this allows you to blend between the fully Denoised image and the raw render.
Corona Image Editor
The Corona Image Editor, commonly referred to as the CIE, is a standalone tool for working with your images. Its user interface is inspired by the Corona VFB, sharing its look and feel, and it offers rich and fast post-processing options for Corona EXRs saved from the VFB such as LightMix, full-featured denoising, tone mapping, LUTs, bloom and glare, curves, blur / sharpen, vignette, etc.
The benefits of the Corona Image Editor are:
The CIE has lower system requirements than working with an image inside any 3D software – it is not necessary to have a scene loaded while you are working with your images, so you can denoise Corona renders outside of the rendering process, for example, reducing the memory requirements significantly.
All LightMix and post-processing settings can be easily shared between the VFB from any host application (such as 3ds Max and Cinema 4D) and the CIE.
No need to copy settings manually: CXRs from the VFB is automatically loaded with their associated settings.
It also works with regular, non-Corona EXRs (in Float format). It is possible to add bloom and glare to them, apply your tone mapping settings or a LUT, etc. Denoising and LightMix are not available for such EXRs because they miss the necessary “hidden” auxiliary data.
It is a portable application, which works with just unpacking, no installation necessary.
Free with a regular Corona license.
Artists can use a realistic camera model which incorporates all the common parameters, such as f-stop, shutter speed, ISO, sensor width, and aperture shape (blades/custom). This allows close matching to live footage. On top of that, you then get access to all the Corona Renderer post-processing options, panorama / VR options, the ability to set focus distance via a static or animated object in the scene, and more.
For older scenes, we have maintained the legacy CoronaCameraMod modifier, to ensure any existing scenes will still work as expected.
Corona Renderer comes with its own scatter system. Corona Scatter is designed to give a complete solution for distributing millions of high–poly meshes or proxies across geometry surfaces. A typical use is the distribution of vegetation such as grass, forests, etc.
Thanks to Corona Scatter you can create scenes with a virtually unlimited number of objects or polygons, while enjoying the luxury of a low memory footprint and high performance. It contains advanced functions like distributing and scaling objects by a texture map, distributing objects along splines, collision detection, etc.
Corona Unified Lister
The Unified Lister currently lists all Corona Lights and Corona Scatters in the scene, letting you access them and their parameters from one convenient panel.
The Unified Lister will be expanded in the next release of Corona Renderer to be the one–stop location for working with all Corona items such as Corona Cameras and Corona Proxies too.
Corona comes with its own proxy format, .cgeo. The format is cross platform (you will be able to use it in 3ds Max, Cinema 4D, Corona Renderer standalone, or any other future platform). It uses compression, so it is small and fast to save, load, and to upload to renderfarms. Proxy models are always converted to millimeters and properly scaled when loading into scenes that use different units.
The proxy contains human–readable metadata at the beginning of each file, for example, the name of the source object and its material, making them friendly to your pipeline.
3ds Max UI Remains Unblocked While Rendering
Ever started a render, then minimized 3ds Max to get at something else on your desktop, only to find you can’t maximize Max again until the render is done? Ever started a render then wanted to check a setting in a different tab in Max, only to find that Max is locked? Those annoyances become a thing of the past, as rendering in Corona does not block the 3ds Max UI!
The UI has tooltips for most parameters, activated automatically when you hover over the controls. There is also an automatically generated online GUI manual you can consult when you do not have 3ds Max opened.
Creating masks in Corona Renderer is an easy process. You can create monochromatic as well as RGB masks simply by specifying Object ID, Material ID or by directly picking objects in the scene. You can combine different selections as union or intersection.
Render Elements Only
Waiting through a final rendering just to discover that you forgot to set one mask can be very annoying. Usually, you would have to create a copy of the scene, turn off lights and GI or set up material overrides to speed things up, and render again. Corona has a better solution: simply set up the missing mask and check the “Render only masks (disable shading)” option to render only the masks and other render elements without the time–consuming beauty pass.
Not Visible in Masks
The Corona Material can be made invisible to masks, while staying visible in the beauty pass. This is a very useful function, for example when you want to create masks for objects behind glass panels.
At any point during the rendering process, you can save the contents of the frame buffer into a single .CXR file. This includes all the rendering passes as well. You can then open another scene or even close the application, and later resume the original render right where you left of.
With one click you can enable the Autosave function, which will save the rendering progress every few minutes in an .exr file. So if your render or computer crashes, you have the latest progress saved. You can either use the .exr as it is if the render had progressed far enough, or resume the rendering from it if needed.
Corona Renderer is extremely flexible. While we aim for realism, we also understand how important it is to “bend” physical laws to deliver the results your clients expect. To keep your artistry free, Corona supports numerous reality hacks which allow you to get exactly the effect you desire!
You can make any light source invisible to the camera, as well as invisible to reflections/refractions. Shadows can be turned on or off, and specific objects can be included/excluded from receiving illumination from any Corona light. Backplates can be easily created with the invisible to GI option. 3ds Max default lights are fully supported.
The Rayswitcher material and texture allow a wide range of artistic tweaks when rendering with Corona. Use them to create materials invisible to the camera, to create materials that don’t affect GI, to reduce or increase color bleeding, to have an object show differently when it is reflected vs. viewed directly, and more.
You can use different environment maps for reflections, refractions and direct visibility from the camera. For example, you can use a clear sky HDRI as a light source and a second cloudy HDRI just for reflections and refractions.
Glass without Caustics
Caustics can be difficult to compute, especially when using path tracing. But in many cases, water or glass look plausible even without caustics, window glass panels being prime examples. Because of this, refractive caustics are disabled by default. This significantly reduces render times, and if caustics are needed they can easily be enabled with the “Caustics” checkbox in the Corona material.
In the image above, the glass and the liquid inside have caustics enabled on the left, and disabled on the right, with no other changes. Although the effect is more realistic on the left, it is not as large a difference as you may expect. Caustics can usually be left disabled unless absolutely necessary for a particular object.
Corona implements its own shadow catcher (matte/shadow) solution. It is a single material with all the necessary controls in one place – there is no need to combine special materials with other special texmaps. It works especially well with our interactive rendering fora rapid camera and illumination matching. Advanced features, such as light illuminators and matte bump mapping, are of course supported.
Using a Corona Camera, you can export images ina Spherical or Cubemap format ready for viewing in a wide range of VR applications.
While stereoscopic and panoramic images can be used in any VR software of your choice, there is especially close integration with theViewer from theConstruct, allowing you to create and manage your warp points in 3ds Max without the need for an external editor.
The Corona Material
Our design goal for Corona materials is to make them physically based, yet intuitive, flexible, and easy to set up, without having to tweak unnecessary sampling values and other confusing parameters. You also won’t have to choose between 10 or 20 different material types, you can pretty much do it all using the single Corona Material.
GGX & PBR Workflow
Corona Renderer uses the GGX microfacet model to deliver realistic–looking metals and other glossy materials. Our implementation of the GGX model fully conforms to the industry standard physically–based rendering (PBR) workflow. This model produces much more plausible results compared to legacy models such as Blinn, Phong, or Ward. Because of our state–of–the–art implementation, using this model does not incur any speed penalty unlike in other microfacet models.
The materials also allow for easy import from third–party applications such as Allegorithmic’s Substance tools, and Quixel’s Megascans.
The new Material Library provides more than 300 ready to use materials, each with a high quality preview. The library includes easy to use functionality such as:
Drag and drop materials into the viewport, Slate, and Compact material editors
Materials can be viewed by category
Can set and view only favorites
Assign a material to the objects selected in the scene
Select all objects in the scene that use a certain material
Many don’t need UV mapping, as they use the Corona Triplanar map
There’s also our resources section which contains more high–quality materials from well–known artists and companies. All these free materials from the Material Library and the resource section are a great way to get started with Corona!
Material previewing uses the same rendering engine as the final frame rendering. The default 3ds Max material preview scene is replaced with a custom, more representative Corona scene, so you get a genuine “What You See Is What You Get” material editor. The example below shows the material preview on the left, and the material in a rendered scene on the right:
Volumetrics and Subsurface Scattering
Corona Renderer also features a powerful approach to Volumetrics and Subsurface Scattering.
Fully Ray Traced Solution
Historically, there were many algorithms for volumetric rendering, most of which relied on interpolation, fakes, and heavy bias to compute the result. Fortunately, with modern CPUs in combination with our research, we have been able to ditch all of these outdated options and go straight for the most accurate, 100% ray traced solution. Even we were surprised by how fast the unbiased, un–interpolated solution could be!
Dedicated Skin Shader
Skin is one of the most complex materials to render, with many unique properties that cannot be covered in an all–purpose shader. The new CoronaSkinMtl shader makes it easy to control and adjust the look of the skin, and renders fast and efficiently with realistic results.
Simple Setup for general SSS materials
Setting up volumetric scattering or SSS is often especially challenging, but Corona Renderer’s implementation in the all–purpose Corona Material makes it simple. It doesn’t need any sampling controls, as all sampling is done automatically. This makes its UI extremely simple: just set up the scattering and absorption properties for Volumetric mode (for liquids, glass, clouds, etc.) or the Amount, Radius and Scatter color for SSS mode (for skin, wax, food, etc.), and press “Render”.
True 3D volume materials with “Inside Volume” mode
The Corona Volume Material offers an “Inside Volume” mode for true 3D volumetric materials. For example, by using a 3D noise map, you can have fog that varies in density in true 3D throughout the scene. Combined with the Corona Distance map, the possibilities are endless!
Fire, smoke, water and more
Corona Renderer is compatible with most features of simulation software such as Phoenix FD and FumeFX, letting you use those applications directly inside 3ds Max – for example, a Phoenix FD explosion is shown below:
You can also load and render the industry–standard OpenVDB format using the Corona Volume Grid object, allowing you to work with the results of simulations exported from Blender, Houdini, Phoenix FD, and more. The material settings in the Corona Volume Grid lets you achieve a range of different looks and effects, even from the same OpenVDB data:
Dedicated Hair Shader
You can’t have a great skin shader without also having a great hair shader! Corona Renderer’s dedicated hair shader keeps with our philosophy of delivering physical realistic results, fast rendering, and a simple UI. Once again, even if you have never rendered hair or fur before, you will get great results even from the defaults.
Corona Renderer also supports native 3ds Max hair and fur, and Ornatrix and Hair Farm, so that the Hair shader will work for you, whatever plugin you use.
Some refractive materials bend light by a different amount depending on the wavelength of the light. This is called dispersion and creates a rainbow effect in the refracted light. Dispersion can be enabled in the standard Corona Material, and is controlled by the single Abbe number parameter. Enabling it adds realism to gemstones, glass, liquids and other materials.
By default, 3ds Max treats bump maps differently, so that some maps do not work as inputs to bump mapping. The Corona Bump Converter resolves this, allowing you to use any map as an input to the bump map channel in a shader. It also lets you use the 3ds Max native Output to apply adjustments to your bump map and get the results you would expect.
Many Maps to Choose From
Corona Renderer comes with many useful maps that you will soon find indispensable, such as Ambient Occlusion, UVW randomization, Multimap, Triplanar mapping, and more. We’ll take a look at just one here, the Corona Distance map.
This flexible map can be used with Corona Scatter to easily achieve effects like keeping paths, roads, etc clear of plants and trees, and can also be used for creative effects such as adjusting materials based on distance to place ripples around an object in water, to cause objects to start glowing as they move close to each other, and more – it really is only limited by your creativity!
In the example below, the ground (with water included) and log were brought over from Quixel Megascans. The “Corona Distance map disabled” image looks a little unnatural, as the water appears completely still.
By using the Corona Distance Map to add extra displacement around the log, blended with the original displacement from Megascans, we can give the effect of ripples specifically around the log. Best of all, since this is procedural, if you move, scale or rotate the log object in the scene, the displacement effect will update automatically.
For quick tests, or even for debugging a scene, it can be useful to override the materials with one simple material. This is easy to set up in Corona, with options that let you leave some materials (such as portals, glass, or light materials) unaffected by the override.
It’s time to explore the individual aspects of Corona, and we’ll start where it all begins, with lights. The whole process of creating lights is designed to give artists complete control over their scene, while being fast and intuitive.
No Sampling Parameters
There are no sampling parameters that you would have to set by trial and error. Lights will always work as expected.
Corona Lights and Corona Light Material
There is no difference in behavior between a Corona Light object and a geometry object with the Corona Light Material applied – both of them have almost the same options and deliver the same results, so it is up to the artist to use what is more convenient!
Lights and Rendering Speed
In Corona, there is very little penalty for using mesh lights which have a high polycount. They will perform as well as low–poly ones with the same shape. Also, directional and IES lights render almost as fast as regular diffuse lights.
No more Dome Lights for HDRI
There’s no need to set up an object to act as a dome light for the HDR image-based rendering – just put your HDRI into the 3D software’s environment and you are done! There is also no need to put downsampled / blurred versions of the map into a GI override slot – HDRIs in Corona always work fast and without splotches, regardless of resolution or complexity.
Corona Sun and Sky System
Corona Renderer was the first production render engine to implement the most accurate sky system available today – the Hošek-Wilkie sky. It is currently selected as the default whenever sun and sky is used, so adding those to your scene will get you instant realistic daylight.
With just a single click, you can set up the Interactive LightMix, a feature unique to Corona Renderer that lets you change the color and intensity of lights during or after rendering.
You can then save your LightMix setups for reuse from any camera or render location within the scene, letting you render just one time and save versions of the render with different lighting. With this, one render can give you a daytime scene, a nighttime scene, different lights turned on and off, and more.
You can also save the separate light passes for compositing or animating later in post-production, which means a single frame can be turned into an animation where the lighting changes.
Rendering with multiple computers is made simple by Corona Renderer. It has its own distributed rendering system, and is also compatible with 3ds Max’s native Backburner and Thinkbox’s Deadline render farm management systems. Any purchased Corona Renderer license (other than a Student License) includes a minimum of three additional render nodes, so you can leverage multiple computers that you own to reduce render times.
Corona is also supported on a number of commercial render farms.
Auto Discovery of Render Slaves
Setting up Corona Renderer’s distributed rendering (DR) is easy. Just make sure all render nodes have Backburner and Corona DR server installed on them. The search process is automatic and Corona Renderer can even search for render nodes during rendering – render nodes will connect and disconnect automatically as you turn the computers on or off, without stopping the render!
Slaves Automatically Gather Missing Assets
When using Corona DR, you don’t have to give a second thought to where your assets are located – slaves will automatically gather models and textures before rendering.
Fast and Simple
3ds Max is spawned immediately on slaves after the DR server starts, letting them begin rendering much faster. Corona DR works with adaptivity, respect VFB render regions, while the UI keeps you informed of the status of all the slaves, how much memory they are using, and how many passes they have contributed to the current render.
Proudly CPU Based
Corona Renderer does not need any special hardware to run. It uses the CPU and you can run it on any processor from Intel or AMD released in the past decade.
Why only CPU?
By rendering only on the CPU we avoid all bottlenecks, problems, and limitations of GPU rendering, which include the unsuitability of GPU architectures for full GI, limited memory, limited support for third party plugins and maps, unpredictability, the need for specialist knowledge or hardware to add nodes, high cost, high heat and noise, and limited availability of render farms. Read our in-depth look at the advantages of CPU-based rendering.
Using GPUs for What They Are Actually Good At
We’re not anti–GPU in any way, we just believe in using them for what they are good at! In the future, you will see the GPU put to use by Corona Renderer, but in the areas in which the architecture excels. This will be in things like post–processing, e.g. bloom & glare, where the predictable, self–similar nature of each calculation can be shared between the processors in an efficient and effective way.
It Doesn’t Have to be Either / Or
There’s no doubt that both GPU and CPU approaches have their advantages and disadvantages, which is why we still see strong products on both sides being developed and used for commercial work.
While completely switching to only a GPU–based solution is just not worth the risk at the moment, you and your company don’t have to be on just one side or the other – with Corona’s pricing options, you can always have a CPU–based approach at your disposal to use based on the needs of each project, whether or not you also have a GPU–based alternative in your pipeline.
And in the Future…
We are always watching and researching existing and upcoming technologies whether that is CPU, GPU or other coprocessors. If things change with the hardware, we won’t rule out changes to the software – but right now, and for the foreseeable future, the hardware just is not at that point.
Intel Embree Ray Tracing Kernels
Corona Renderer uses the Intel Embree ray tracing kernels, the fastest CPU ray tracing primitives on the market. Since they mesh well with the Corona architecture, they are an important factor in its performance.
Compatible with third-party tools such as Allegorithmic’s Substance Painter and Quixel’s Megascans
SSS mode for wax, marble and other materials that do not use Refraction or Translucency
Volumetric scattering and absorption mode for fog, mist, and for colored glass, liquids and other materials that use Refraction or Translucency
Fresnel reflections, anisotropic reflections
Dedicated material for skin
Three independent Subsurface Scattering layers
Two independent Reflection layers
Dedicated material for hair and fur
Colored and Colorless reflection layers
Color controls via melanin amounts, or directly
Adjustable random glints
Similar to 3ds Max Blend material
Combines multiple materials instead of just two
Accelerates lighting in interiors with small windows
Identical performance to CoronaLight
Various non-physical settings
Textured emission (useful for backplates)
Uses different material for different ray types: direct, GI, reflections, refractions
Custom backplate textures
Screen, spherical, or no projection
Supports glossy surfaces
Lights work additively (illuminators) or subtractively
Simplified material for volumetric scattering and absorption
“Inside Mode” allows for true 3D volumetric materials
3ds Max materials
Blend (including nested blend materials)
Support for 3ds Max physical material
Corona Official Toolbar
Provides one-click access to many Corona Renderer functions, such as creating a Corona Camera from the current perspective view, opening the VFB, opening the Material Library, creating Corona Scatters, Proxies and Lights, etc.
Corona Unified Lister
A single lister tool that provides access to and control over all Corona Lights and Corona Scatters in the scene
Corona Camera can render to spherical or cubemap format, supporting a wide range of VR apps
Easy set up, with default settings handling 99% of cases
Conventional stereo rendering (non-360)
Bloom & Glare supported for spherical VR images
Slaves can join or quit the render session after it has started
Auto discovery of slaves on local network
Auto sending of assets to all machines (only if required)
Pass, Time and Noise Level limits can be used
Can be enabled / disabled during rendering
Drag and drop any texture into the 3ds Max environment slot
No dome object required
Uses importance sampling
Global material (for volumetric effects – fog)
Cross-platform proxy format: .cgeo
Faster save/load/display of large scenes
Compressed format to save disk space
Supports animated meshes
Fast and simple scattering tool
Supports multiple distribution and scattered objects
Supports scattering on splines
Supports scattering in regular patterns
Random translation/rotation/scaling of instances, with optional discrete stepped values
Supports aligning instances to local normal
Supports millions of instances
Textured density, scale
Vertex paint support
Optionally avoids objects intersections, with tweakable inter-object spacing
Fast generation and viewport preview using multiple threads
Included Scatter Lister plugin to easily access and control all scatters in a scene
Allows loading and rendering of OpenVDB files
Useful for importing simulations such as clouds, smoke, fire, liquids, etc.
For Corona Renderer 2 and newer, you will need a CPU that supports the SSE4.1 instruction set (any processor from within the last 10 years). Here is a list of compatible CPUs. The Licensing Server may run on legacy CPUs that do not meet this requirement (however, the computer won’t be able to be used for rendering).
There are no further specific hardware requirements.
3ds Max version
Autodesk 3ds Max x64 version 2013-2020 (the hotfix released 29 March 2019 adds support for 3ds Max 2020)
64-bit Microsoft Windows (7, 8, 8.1, 10)
Installation requires administrator privileges
Distributed rendering also requires matching Backburner version
Oldest supported Phoenix FD version is now 3.11.04 with Corona 3.
64-bit Microsoft Windows (7, 8, 8.1, 10) or macOS (10.7 or newer)
Installation requires administrator privileges
64-bit Microsoft Windows (7, 8, 8.1, 10)
Corona Renderer 4 for 3ds Max
Some of the highlights of what Corona Renderer brings to 3ds Max:
Caustics – We think these are the best caustics in any render engine!
– Easy to set up with just a click or two
– No complex parameters
– Fast to render
– Handles reflective caustics and refractive caustics
– Refractive caustics can include dispersion (hello Dark Side of the Moon!)
– Each light source can have caustics enabled or disabled
– Works as expected with LightMix and other Corona tools
Pick objects, and set DOF focus point in the rendered image – works in both the VFB (during IR, final render, or after rendering is complete) and in the docked viewport IR.
Fisheye mode for cameras – perfect for both interior and exterior renders, any Corona camera can be given a fisheye lens, with all the controls you need to get the result you want.
Intel AI Denoiser – works on any CPU (not just Intel), giving you access to AI denoising for final renders that can be done on any machine.
Multiple Suns and Environments for LightMix – you can now add multiple Corona Suns to a scene, and set up a list of multiple environments, which you can then swap or blend between in LightMix.
Rest (unassigned) LightSelect layer in LightMix can now be denoised and saved like any other LightSelect – no more noise for those elements that can’t be added to a separate LightMix layer on their own (or that you simply don’t want to add to a separate layer).
Improvements to overlapping volumetric media – so those clouds that overlapped will now look as expected!
New Image Filtering – makes noise less noticeable to the eye, getting away from the “pixel-by-pixel” look that CGI noise has. In effect this speeds up rendering, as you will need less passes or time to get to a satisfying visual quality.
Adaptive Light Solver – now fully functional in all cases, the Adaptive Light Solver is now enabled by default, and gives great improvements to render times.
Major New Features in v4
Not too long ago, having fast, easy to use GI was the holy grail for render engines. Now that has been achieved, the question is – have we reached the ultimate in realism, or is there some aspect of the real world that is still not fast and easy to create in our renders?
The answer is that renders are missing caustics – sometimes subtle, sometimes bold, they appear in a great many places and we are used to seeing them in the real world, whether that is the classic examples that first spring to mind like water in swimming pools or light through a glass of water, to ones we may not think of such as sun reflecting off a bathroom mirror onto the opposite wall, or sunlight off the body and wheel rims on a car, or from the myriad of windows on a building onto the environment around it.
Corona Renderer 4 aims to change all that, and make caustics easy to add, simple to control, and fast to render.
Setup is easy – just enable the new Fast Caustics Solver, and instantly you will get reflective caustics from all materials in your scene. Then for any material with refraction, where you want refractive caustics, just enable the Caustics check box in that material. If you want the caustics to split white light into component colors, just enable the Dispersion effect in that material.
You can then choose to disable particular light sources from affecting caustics, if you want to optimize render speed by keeping the calculations only to those light sources that will have a major effect. One thing to note if you are using multiple environment maps is that you can only enable or disable caustics for all of those at once, and not individually.
AND THAT’S IT. That’s pretty much a whole tutorial on how to use caustics, in just a couple of paragraphs. You don’t need to know or change any strange and unusual settings, just click on a few checkboxes and you are good to go!
Caustics will respond as expected to both displacement and bump mapping, and will work as expected in LightMix (any color and intensity changes you make to a light source will affect the caustics from that light source).
If you want extra control over the caustics, you can add a CShading_Caustics render element, and check the “Only in caustics element” option under the caustics settings. This will let you composite the Caustics layer in post, so that you can mask it, make it brighter or darker, and so on.
One thing we want to be clear about, just to make sure you don’t get your hopes too high – “fast to render” does not mean renders will take the same amount of time with and without caustics! No matter how efficiently you do extra work, it is extra work, and so will always take longer; that’s true for you, and for Corona Renderer too!
It is highly scene dependent, on many factors, such as:
– Are you using reflective caustics only, or refractive caustics as well?
– Do the refractive caustics include dispersion or not?
– How many materials in the scene have refractive caustics?
– How many light sources have caustics enabled and so are considered in the calculations?
– How much “screen space” the caustics occupy?
– …and so on.
As a very approximate guideline, when including refractive caustics, it may take 2 or 3 times the render time compared to the same scene with caustics disabled
Object and DOF Focus point picking in the render
The VFB has a new Pick mode, and when this is enabled (during IR, final rendering, or after rendering):
Left click will select the object you click on. It also supports +CTRL to add to the selection, +ALT to remove from the selection, and +SHIFT to alternately add and remove from the selection.
Right click opens a popup menu which allows you to set the current camera’s focus distance to the clicked point (available only for perspective cameras). When using Depth of Field, this means the point you clicked on will be in sharp focus.
Note – There is a current limitation that you can’t pick objects/set focus within render regions
The docked IR viewport also has similar functionality, but without any Pick mode needing to be enabled:
Left click will select the object you click on, just as with the VFB.
Right click opens up a popup menu which lets you set the focus point, just as with the VFB.
The right click menu also contains other options previously found under the Menu button, such as stop, restart, copy to Max, copy to clipboard, etc.
As part of this change, the menu button in the top right of the viewport has been changed to let you swap to any other Max viewport (note that this disables Corona IR in the viewport, of course).
Does exactly what you would expect – adds a Fisheye projection mode to the Corona Camera, which has all the settings you need to fine-tune your results to meet your needs whether you are rendering interiors, exteriors, or anything else!
Intel Open Image Denoiser
The Intel Open Image Denoiser is an AI denoiser that runs on any CPU (despite the name, you don’t have to have an Intel CPU!). It is much faster than the Corona High Quality Denoiser, though not fast enough to use in IR so it is for final rendering only.
As with any AI denoiser, it has some advantages and disadvantages compared to the Corona High Quality denoiser – while significantly faster, it does mean that the AI can generate detail where there was none, and that running it on the same frame twice could produce different results so it may not be recommended for animations.
Multiple Corona Suns and Environments for LightMix
This new functionality lets you set up and use multiple Corona Suns and multiple environments, letting you use LightMix for more extreme changes such as going from day to night, all in one render.
Since you can add separate suns, you can now position the suns at the appropriate angle for the time of day (simply changing the color of one sun was not going to make it look like a realistic evening set up while the sun was still overhead like noon!)
To add multiple environments, you use the new “Multiple maps (LightMix)” checkbox in the Scene settings in the Render Setup dialog, and then you can open the list of environments to add as many maps as you like.
One thing to note, to use this new functionality you will need to disable the Adaptive Light Solver. Basically, you trade the speed boost of the Adaptive Light Solver for the extra freedom to have multiple light set ups in just one render. Also, with the multiple suns and environments active, your Beauty pass will likely not be usable, but that’s ok as the functionality is intended for LightMix!
While intended for LightMix, if you wanted to render Tatooine with its two suns, now you can!
As well as the new multi-sun and environments, there are other improvements to LightMix. The “Rest (unassigned)” layer can now be denoised and saved just like any other layer. This is ideal where you had light materials that couldn’t be placed in their own layer (such as Light materials with Emit Light disabled), or where you just didn’t want to assign light sources to a specific layer.
All LightSelects will have denoising enabled by default (only when denoising is enabled overall, that is).
Lastly for LightMix, you can now have more than one LightMix element displayed in the VFB. At present, all LightMix elements use the same settings, but this is in preparation for future updates which enable you to create multiple LightMix setups in the scene (rather than saving and loading the different set ups as .conf files).
Corona Select Map and Material
Have you ever had a scene where you needed to save three different materials for a sofa? Did you leave the materials in the Slate material editor and hope you never clicked “Clear View”? Did you save three different versions of the scene? Did you create three copies of the sofa and switch which one was visible?
Now all that can be handled much more easily. The Corona Select functionality comes in two forms, a Map and a Material, and we’ll consider the Select Material here though the Map works the same way.
The Corona Select Material lets you connect up multiple materials, and then choose which should be active through a radio button. In effect, this means that the sofa in our previous example will carry its own “mini-library” of materials with it – you only need one copy of the scene, one copy of the object, and you can’t accidentally delete any of those materials. You could even merge that object into another scene, and it would take that collection of materials with it.
The radio button can be keyframed, which means you could set up three frames of animation, each with one of three radio options selected, and then set the machine to render frames 0 to 1 to create a version with each material in it without having to manually change the radio button and start rendering each time. Or of course, create an animation where the material on an object changes at set points in the animation.
As you can see, it opens up a lot of possibilities, for what seems like a deceptively simple addition!
Improvements to Corona Scatter
Several improvements have been made to Corona Scatter. First, rather than have three maps to define scaling in the x, y and z, Scatter now uses just one map interpreted in RGB, where the red component affects the scale in the X axis, green for the Y axis, and blue for the Z axis.
Also, new modes have been added for how to interpret scale maps. The Map Fixed mode is the default, and there the 0 to 1 color range in the map (greyscale, or separately for the R, G and B for an RGB map) will correspond to the “From” and “To” values. In other words, the color value will correspond to the size of the scattered object.
The second mode is the Random Amount mode. In this mode, the 0 color represents no randomization at all (so the scattered object will be its original size), and the 1 color value represents maximum randomization, so the scattered object will vary somewhere within the full range of the “From” and “To” values. In this mode, a scattered object may be a different size from another scattered object, even where the same color value was used (except for 0 color values, where all objects will be their original size)
The third mode is the Legacy mode, provided solely for compatibility with scenes created in earlier versions of Corona. In this mode, the random scaling is calculated between the “From” and “To” values, and then the result is multiplied by the color value in the map – this means that a color value of 0 will always give an object size of 0, in other words, an invisible object with no scale at all. Other than for preserving results from earlier scenes, there is no need to use this mode.
Using the RGB mode lets you control scaling in the X, Y and Z independently:
BONUS INFORMATION – Don’t forget you can use the Corona Distance map as the input to the map scaling, allowing scattered objects to grow taller close to other objects, e.g. grass around a tree where the lawn mower wasn’t able to get so close.
Improvements to overlapping media
The biggest effect of this change is to ensure that overlapping volumetric media, such as clouds, now render as expected.
The change does also affect situations where a refractive material overlaps itself. Because this looks “different” to the previous versions of Corona, when you load an old scene you will be given the option to switch to the new, more correct calculations, or stay with the older method if you need things to look exactly as they did before. Note that the old method will not look wrong to the eye, but be assured that the new results are the more-correct!
High Quality Image sample filtering
The way noise looks in a render is often the biggest giveaway that it is a CG image. It has a particular, harsh look, varying pixel by pixel, so it is very obvious to the eye. The new High Quality Image Filtering option “smooths out” the noise, making it less harsh and obvious, so that you can use less passes to reach a visually acceptable level of noise (especially when followed by the Corona High Quality denoiser).
Note: Neither of the AI denoisers will work with the new filtering, so it is automatically turned off if either of those is selected. As with all things AI, the software has been “trained” on particular examples of “noisy version of the image vs. clean version of the image” and that training has been with the old, harsh type of noise. We are working with Intel to have their AI denoiser retrained to work with our High Quality Image Filtering, so hopefully that restriction will be removed in the future!
Adaptive Light Solver
The Adaptive Light Solver has been in Corona Renderer for the last few versions named as the “New Light Solver” – now that the last polish has been done to it, it is the default solver going forward and has been renamed. It gives significant improvements in render speed, particularly where there are lots of light sources, or lots of objects occluding light sources.
Note: It is recommended to always use the Adaptive Light Solver, and only disable it when you want to take advantage of multiple suns and environments in LightMix.
We are always working on optimizing Corona Renderer’s use of memory, and here are the updates in Corona Renderer 4:
Corona Proxy now has a lower memory consumption when “Keep in RAM” is disabled. The only thing to note is that Full Mesh visualization mode requires “Keep in RAM” to be enabled (it is automatically forced on if you choose Full Mesh visualization – so best just to use Full Mesh visualization when setting up the scene, and switch to any other visualization mode with “Keep in RAM” disabled for rendering)
Displacement computations now have a lower memory consumption.
Added a checkbox for turning on memory optimizations of geometry, in the Performance section of the Render Setup dialog. Note that this option was previously in the Development/Experimental section as the “LowMem” option, and the functionality remains the same – it will reduce memory requirements by 5 to 10%, but at the cost of rendering being 5 to 10% slower (which is better than the speed loss from running out of RAM altogether).
Checkbox for enabling/disabling denoising (in the VFB and CIE)
This is useful for quickly comparing the denoised and non-denoised image, usually when checking whether denoising has blurred any details too much. It is enabled by default (if denoising is turned on, that is!). It works only in regular rendering, so it does not work in interactive rendering. Note that denoising will be calculated when selected, whether this checkbox is on or off – the checkbox only controls the result you are viewing in the VFB.
By default, images stored in render history are now displayed with their original postprocessing parameters instead of using the current VFB parameters, so the render history can be used to compare different versions of tone mapping, denoising etc. A checkbox allows you to enable the previous functionality where all history renders are displayed using the current post-processing settings, and not the settings in use when they were saved.
New spinner added that lets you upscale an image rendered in IR. Located in the System settings window, it will render at a lower resolution than the VFB then upscale the image to fit – for example, with an upscaling of 2, it will render at half the size of the VFB then upscale the image to fit the VFB. This may be useful on High-DPI displays.
Added green-magenta tint to the VFB, CoronaCamera and CoronaColorCorrect map. This is a common adjustment in photo-processing apps, and it allows full adjustment of the white balance.
Bloom and Glare progress bar added to the VFB.
The “Show VFB” button in the Render Settings now opens the Corona VFB with the correct resolution and render regions, even before the first render was started.
Added an option to save and load .conf files in the Corona Camera, same as in the Corona VFB. This allows for saving and loading post-processing and tone mapping presets, and freely exchanging them between the VFB, the camera, and the CIE (in any direction).
Speed of Bloom & Glare optimized (now around 5% faster).
When resizing the VFB by double clicking the rendered image, the maximum size of the VFB is now limited by the resolution of the monitor which is currently displaying the VFB.
Reworked the VFB render region UI:
The region button is now sticky. This is a first step in transforming VFB to using separate function modes. VFB stays in this mode until you deselect the region button or select a different mode (e.g. Pick mode).
Regions are now editable only in the “Region” mode, and in this mode the regions are drawn thicker for easier adjustment; when not in edit mode they are drawn thinner and half-transparent to make them less obtrusive and distracting.
When multiple fuzzy regions overlap, only the outline is drawn now (fuzzy regions are where the outside of the render region is “feathered and blended” into the original render, represented by a green area around the render region – you can draw these by holding CTRL and click-and-dragging at the edge of a region).
If motion blur is disabled, IR is no longer restarted when shutter speed of CoronaCamera changes.
If depth of field is disabled, IR is no longer restarted when F-stop of CoronaCamera changes.
Changing global f-stop now restarts IR if DOF is enabled.
Changing global shutter speed no longer causes scene reparsing in IR when motion blur is disabled.
The + button can now be used to add Corona Volume Grid objects to the list of objects to be scattered.
Corona Scatter now supports maps which use Object XYZ mapping, as well as the previous World XYZ mapping.
Corona Scatter can use animated maps in the density map, without noticeable viewport slowdown.
Performance improved when using Density map and Max Limit of instances (scattering of older scenes is not affected unless the Legacy checkbox is disabled).
Preserving materials from the Material Override now also works for multi/sub materials.
Optimized cancel time (up to 80% faster).
Added Hue Shift and Green-Magenta Tint to CoronaColorCorrect map.
CoronaColorCorrect map now has an option to use the settings from another CoronaColorCorrect map – this means you can create one CoronaColorCorrect as the master, then you can connect that to as many other CoronaColorCorrects as you choose, allowing the same color correction processing to be applied to multiple maps while only having to adjust the color correction parameters in one place.
Corona Bitmap automatically reloads modified texture without the need to constantly check it on hard drive, which fixes freezing / stuttering issues which used to happen under specific conditions.
Added more robust inside detection for the CoronaDistanceMap – this mode is now the default.
Optimized the CoronaDistanceMap – mesh is reparsed only when rendering (outside of Material Editor). This makes viewport manipulation of related meshes MUCH faster.
Optimized opening render settings dialog – more noticeable in newer versions of 3ds Max.
Added PhoenixFDOceanTex and PhoenixFDGridTex to the list of maps compatible with Corona.
Added support for motion blur for Ornatrix hair.
Changed the way installer installs components:
– All components that do not require additional downloads (i.e. everything except for Material Library and NVIDIA denoiser) are now always reinstalled even if you’re installing the version that is already installed.
– Material Library and NVIDIA denoiser are still downloaded & reinstalled only if the installed version is different from the one that would be downloaded or if some of their files are missing on the hard drive.
New icons for the CIE, DR server and Licensing server
Corona color picker now supports alpha value (where applicable)
CoronaBitmap will now automatically open file dialog when it is plugged into any bitmap slot in render settings
“Export” and “Export+Render” buttons in render settings now remember the last used export path
CoronaLights are now drawn in viewport with axis-aligned CoolLines(TM)
Render stamp help dialog now can be closed with the “X” button
Histogram controls in curve editor are now disabled when no input map is connected
Fixed histogram in the curve editor not updating when input map is added or removed
Limitation of the maximum number of autosaved files is now respected when render stamp variables are used in the autosave file name (previously, if a render stamp variable was used in the autosave file name, then Corona would save more than the specified maximum number of files).
The file counter is resumed from its last value even after restarting Corona.
In the case of a final autosave render, the file name suffix is now “end_<counter>” instead of “end<counter>”.
Corona Renderer 3 for Cinema 4D
Some of the highlights of what Corona Renderer brings to Cinema 4D:
Interactive Rendering, to make test renders a thing of the past
LightMix, to change color and intensity of lights before, during or after rendering
the Corona Node Material Editor, to make creating materials easier than ever (any version of Cinema 4D supported by Corona Renderer)
Denoising (CPU, and GPU if you have a compatible NVIDIA GPU)
Tight integration with Cinema 4D
Compatibility with many native Cinema 4D lights and materials
Compatibility with Team Render
Corona Renderer 3 for 3ds Max
Some of the highlights:
GPU Denoising gives near-instant denoising when using IR (and can be also used for non-interactive rendering).
CoronaMultiMap and CoronaUvwRandomizer feature a new randomization by Mesh Element mode.
Improved IR performance keeps everything smooth and snappy.
Displacement improvements allow you to use lower Displacement settings with the same image quality, lowering memory usage by up to 50%.
Various memory optimizations let you save up to 2.5 GB for an 8K render (or more for larger resolutions).
A focus on fixing bugs.
Major New Features in v3
As part of the overall plan to make Interactive Rendering faster than ever, we implemented NVIDIA’s GPU denoising, which lets you run near-instant denoising on your Interactive Renders!
Fast Preview Denoising is enabled by default for interactive rendering (the setting can be found under the Performance tab in the Render Setup if you wish to disable it):
Please note that this feature requires an NVIDIA GPU installed, and the GPU needs to be Kepler or newer. NVIDIA’s denoiser does not support all mobile GPUs, so this may not work on your laptop.
If you choose, you can use GPU denoising for your final renders too by selecting the “Fast Preview (NVIDIA)” option in the Denoising drop down (Corona “Full Denoising” has been renamed as “High Quality” under these options, if you are looking for it!). You can also use the GPU Denoising in the Corona Image Editor.
If you choose to use this new GPU denoising for final renders, please keep these points in mind:
– GPU Denoising may blur details and result in artifacts or a “painterly” look to your image. High Quality Denoising uses more precise algorithms to ensure effective denoising while preserving detail in the end result.
In the image below, while it has removed more noise at these early passes, the GPU denoising also loses some detail in the grass and flowers, resulting in a softer, blurred look that may not be desired:
And in the image below, loss of detail can be seen in the texture where the AI denoiser “hallucinates” especially around areas of high contrast, as well as having a blurrier look (of course, this difference reduces with more passes):
– GPU denoising has no temporal consistency, so results may vary from frame to frame for animations, which may cause flickering or other unwanted effects. Of course, it may not, but it is something to keep in mind!
– Your GPU memory will determine the maximum resolution that can be efficiently denoised (as using shared memory will be slower), and the number of render elements being denoised may also play a part in how efficiently GPU denoising can work.
The NVIDIA AI denoiser can be selected as the final denoising mode in the Scene tab of the Render Setup – in this mode, the rendered image is denoised with each VFB refresh.
Corona Renderer’s implementation of the NVIDIA denoiser preserves details in reflections and refractions, unlike some other implementations of the denoiser in other software.
The NVIDIA AI denoiser can also be enabled separately just for IR in the Performance tab of the Render Setup.
The NVIDIA AI denoiser is an optional component in the installer and requires an additional download (similar to the Material Library). This component is pre-selected when a supported NVIDIA GPU is detected on the computer.
Denoising time is displayed in the VFB Stats tab.
Optimized IR restarts, making it more responsive.
IR restarts with the new light solver are now significantly faster.
IR restarts in the Corona VFB are now generally faster (comparable to the docked VFB).
The improvements to displacement result in better image quality without the need to sacrifice render time:
Perhaps more importantly, it allows the lowering of Displacement settings to get equivalent quality with faster parsing and lower memory usage. It is on by default in all new scenes, and when loading older scenes, you will be asked whether to switch to the new displacement mode with a click of a button to lower the RAM usage or to preserve the original settings to keep original scene appearance.
In the example scene below, thanks to the new improvements, Displacement quality could be lowered from 1px to 4px with almost no visual difference, reducing memory requirements from 11.6 GB to 5.2 GB.
The new processing is disabled when loading a scene saved with a version earlier than Corona Renderer 3 to avoid changes to the scene’s appearance on rendering (a dialog box will let you enable it if you choose).
It is enabled by default in all new scenes, and the default displacement edge size in screen space has been changed from 2px to 3px.
Back in the day, RAM was cheap, so we focused on rendering speed even if this meant higher memory usage. However, the market has changed and RAM now costs a premium, so we’ve revisited Corona Renderer’s memory consumption.
Thanks to a variety of optimizations and improvements, you can expect savings of up to 2.5 GB for an 8K image without having to change any settings (although this will vary by scene, of course).
For testing, we wanted to use a regular scene and not one specially created to maximize memory savings, so we chose the much-loved Benchmark scene and renderer it at 8,000 x 4,500. The test was run using Release Candidate 7.
Corona Renderer 2 required 20.3 GB for an 8K render, while Corona Renderer 3 required 19.6 GB, in this instance saving around 0.7 GB without any changes to the scene or settings.
If we choose to also use the improved displacement on loading the scene, there is a final savings of 6.3 GB without losing any quality – and this scene doesn’t even make heavy use of displacement! You can also notice the improvements from the sharper textures at grazing angles, listed in the smaller changes further down the page, on the ground in the background.
Summary of Memory Optimizations:
Optimization of random sampler memory usage – High-res images render with less memory. There should be no impact on the amount of noise (noise pattern itself can change).
Reduced Corona Renderer’s geometry memory usage by 16.6%. Note that 3ds Max and Embree still need their own geometry data in memory too, if you are wondering why this does not translate to an overall memory savings of 16.6%!
Reduced memory usage of the new light solver with volumetric media by up to 86% – this brings it into line with memory usage in the old light solver.
Low memory warning now gives a bit more detailed breakdown of Corona Renderer memory usage (split into geometry, textures and frame buffer).
To make it easier to track and breakdown Corona Renderer’s memory usage, we’ve also added new renderstamp variables which let you monitor memory usage at all stages during rendering:
Randomization by Mesh Element
Both the CoronaMultiMap and the CoronaUvwRandomizer now support randomization by Mesh Element (one contiguous triangle group). A prime example would be randomizing the color of each individual leaf on a tree, randomizing different planks in the keg, and randomizing the color of the fruit, all using the MultiMap and randomizing by Mesh Element:
Or randomizing the marble texture on the tiles using the UvwRandomizer in Mesh Element mode to avoid repetition:
Support for additional image file formats
Corona Image Editor and Corona Standalone:
Extended the list of file formats which the frame buffer can save to, and when saving the user can now specify the output color depth and whether to include an alpha channel.
Added support for Kodak Cineon, Adobe PSD Reader, SGI file, RLA image file, and DDS image file formats.
First implementation of Unified Lister
This first implementation of a unified Corona Lister is in place – it lists Corona Scatters and Corona Lights in this release (with more object types to be added in Corona Renderer 4).
New Light Solver Improvements
Optimized the new Light Solver, giving an overall speedup of between 5 – 15%.
The initialization of the light solver is now parallelized. The solver is also re-initialized only if some lights changed, making IR restarts significant faster.
Improved sampling of translucent objects.
Improved light sampling in cases where geometry is very close to a spherical light.
Fixed inefficient sampling when the shading normal differs significantly from the geometry normal.
Fixed square artifacts that appeared when non-physical lights (invisible or transparent lights) are used in the scene.
Fixed the new light solver producing rectangular artifacts when textured lights are used.
Fixed NaNs (black pixels) occasionally appearing in the rendered image.
Reduced the memory usage for volumetric media (in some cases, down to 14%, an 86% savings compared to the New Light Solver in Corona Renderer 2).
Fixed bias when rendering portal hidden behind another portal.
Fixed crash in new light solver with extremely bright lights.
Fixed a few other occasional crashes.
No longer called “Experimental” due to the fixes so it should work in most scenes – however, we have held off on making it the new default for now.
Optimized VFB redraw speed.
UI controls in object lists in Scatter have been reorganized to make more space for object names.
Unified Look & Feel of Corona Renderer’s warnings/question popups.
The Corona Color Picker now remembers the sRGB checkbox state and color range between sessions.
Fixed Corona Color Picker not taking into account values entered via keyboard right before OK is clicked.
The Corona Camera shutter offset now has a range from -1 to 1.
Changed the order of operations in the installer, so that components which need additional downloads (the material library, or the NVIDIA AI denoiser) are installed last – this means if the installation is canceled during the additional downloads, everything else should already be properly installed.
Unsupported materials are now gray for GI rays, which removes the red bleeding of the material into the scene:
Improved texture sharpness on grazing angles (for diffuse, bump, displacement, etc.) – in the image below, notice how definition and detail are preserved:
In the viewport, scatter is now able to toggle the instance color between the original object wire color and the scatter object color.
In Corona Scatter, the rotation and scale of the original instanced objects no longer affect the scattered instances (this does not change existing scenes unless the Legacy checkbox is disabled).
Installation and Licensing
Corona Renderer now requires SSE4.1 CPU for all tools – including licensing server. We had hoped to continue supporting the licensing server on legacy CPUs, which we mentioned in the Corona 2 release blog – unfortunately, this has proven to be time and cost prohibitive and we had to change our plans. Only CPUs more than a decade old will be affected.
Licensing and DR servers are now 64-bit applications.
The CIE, Corona Standalone, and DR and licensing servers are now installed to sub-directories by default, to avoid problems with multiple versions of the same DLL being installed at the same time.
Fixed IR not restarting when render elements were modified.
Fixed non-filtered render elements not being correctly rendered in IR.
Fixed unnecessary reparsing of the the environment map in IR.
IR no longer unnecessarily restarts when a map not attached to the scene is modified.
Fixed some unnecessary IR restarts when navigation the material editor.
IR is no longer restarted when switching between Bitmap nodes in the Slate material editor.
Fixed IR restarts when Scatter visualization settings (dot, box, full, etc.) are changed.
DR Bug Fixes (and improvements)
DR is now able to automatically discover slaves connected through all network interfaces.
IFL image sequences are now correctly handled by Corona DR.
Integrity of scenes sent via Corona DR is checked, and reported in the case of integrity failure.
Fixed Tilt&Shift in XRefed camera when rendering with DR.
Added an option to restart slave 3ds Max after each render (we implemented this as a workaround for some potential problems that a small number of users may encounter with DR server freezes).
Fixed DR slaves not fetching missing assets from master in some cases (for example bitmaps referenced by atmospheric effects).
Path to 3ds Max is now correctly auto-detected even when the 3ds Max is reinstalled to a different path, unless the path was explicitly overridden in the configuration file.
Fixed some cases where rendering non-camera view leads to an incorrect result.
Fixed DR slaves sometimes introducing “dots” of darker color in the CMasking_ID render element.
Added a button in the DR Server for opening the folder with EXR images which were sent to master.
Added a button in the DR Master to the DR render settings for opening the folder with EXR images which were sent from slaves.
Better error reporting when the slave 3ds Max fails to start.
Scatter Bug Fixes (and improvements)
The density spinner below distribute-on object list has been renamed to Factor spinner since it better describes its purpose (see its improved tooltip for further details). Also both Factor and Frequency spinners are now disabled when they are not considered in current scattering mode.
Fixed Scatter to respect Material IDs set on polygons of distribute-on objects while evaluating MultiMap plugged into density or scale map slots. Behavior in old scenes is not changed unless the Legacy checkbox in the Scattering rollout gets unchecked.
Fixed occasional crash in Scatter when displaying instances as wire boxes or point clouds in the viewport.
Fixed crashes occurring while scattering large amounts of instances.
Tooltips for Factor and Frequency spinners in Scatter are now displayed also for their labels; the tooltips now also state under which circumstances the spinners are enabled.
Fixed problem where scatter density map updates were not reflected in scatter viewport display in 3ds Max 2017.
The “Original wire colors” checkbox in Scatter is now disabled for Previz types for which it is not supported.
For surface scattering mode, fixed the Count control so that it is disabled when the scatter is switched to UV map scattering.
Fixed the Dots viewport display mode to display dots at the correct places for animations (this bug did not affect rendering, only the viewport display).
Fixed the distribute-on object density and instanced object frequency spinners so that they get updated when changing the object selection (in the lists above them) via keyboard input.
Reworked the MAXScript interface for the Scatter. The old interface is no longer available. See https://corona-renderer.com/wiki/maxscript#corona_scatter_api
General Bug Fixes (and improvements)
Fixed “Region” button update in VFB when regions were enabled/disabled via MAXScript.
System-wide settings (accessible through the System Settings dialog) are now accessible from MAXScript.
Fixed unlinking target in targeted camera.
Fixed CoronaCamera occasionally having an incorrect mesh after loading a scene.
Daylight system no longer creates a target for the CoronaSun.
Fixed crash when trying to run Corona Renderer on unsupported CPU – now an error message is shown instead.
LightMix now properly works with lights having “Occlude other lights” disabled.
Fixed undo/redo not working with various object lists in Corona Renderer UI – scatter instance/distribution objects or density and frequency values, material override exclude list, etc.
Fixed diffuse texture being visible in reflection render element when non-physical lights are used.
Minimized problem of installer progress log window blinking when downloading additional pack files.
Fixed Corona Light gizmo scaling in viewport when scene units changed.
Fixed crash when CoronaSun is used as an input node for Corona Distance Map.
Fixed CoronaSun object cannot be selected when using the Daylight system without a Sky light.
Fixed auto-scaling of the Kelvin temperature result in volumetric rendering (CVolumeGrid).
Fixed occasional crash in denoising.
Fixed loading denoised image from the Render History (previously, this may have resulted in NaNs when using Regions, Render Selected, etc.).
Fixed incorrect unmapping of Filmic tonemapping.
Fixed incorrect results of CoronaBitmap used as screen mapped environment.
Fixed incorrect shading result of CoronaRoundEdges map (in fast mode) on displaced geometry.
Fixed crash occurring when attempting to show removed render element in Corona VFB.
Corona Standalone is no longer showing modal error dialogs in silent mode.
Fixed undo/redo for Clear list option in right-click menu on “+” button in various object lists.
Fixed Clear list option in right-click menu on “+” button in Scatter not to cause crashes.
Fixed CoronaColorCorrect “Invert colors” being ignored when the map is assigned to a bump map slot.
CoronaColorCorrect now preserves alpha of the input map.
Fixed rare crashes with non-manifold geometry (e.g. geometry where two or more triangles only share a single vertex, where an edge is shared by more than 2 triangles, self-intersecting meshes, etc.).
Added an error message when rendering a mesh with changing topology and velocity render element is enabled.
Updated the readme.txt for the “Unpack” option of the Corona Renderer for 3ds Max installer.
Oldest supported Phoenix FD version is now 3.11.04.
Corona Renderer 2
Released on June 25, 2018
Works with 3ds Max 2013-2019
Selected Key New Features
Heterogenous media support added
Initial V–Ray compatibility added
150 materials added to the Material Library
Corona Official Toolbar added
Corona Renderer 1.7 (hotfix 4)
Released on October 24, 2017
Works with 3ds Max 2012-2019
Selected Key New Features
Material Library with over 300 materials added
Hair, Fur and Skin rendering added
Dedicated Corona Camera
Faster rendering with the inclusion of DMC sampler
1.6 (hotfix 3)
Released on April 24, 2017
Works with 3ds Max 2012-2018
Selected Key New Features
Corona Image Editor added
Triplanar mapping added
Corona Scatter can now scatter in regular patterns and along splines
Improved Distributed Rendering
1.5 (hotfix 2)
Released on October 10, 2016
Works with 3ds Max 2012-2017
Selected Key New Features
Interactive LightMix added
New VFB post-processing, e.g. Bloom & Glare, LUTs, and Filmic Tone Mapping
Corona Distance map added
1.4 (hotfix 1)
Released on May 16, 2016
Works with 3ds Max 2011-2017
Selected Key New Features
VFB History and Multiple Render Regions added
Texture baking added
VR camera added
Released on November 3rd 2015
Works with 3ds Max 2011-2016
Selected Key New Features
Corona Proxies now support animation
Corona Layered Material added
Advanced ‘Render Selected’ options
1.2 (hotfix 1)
Released on July 29, 2015
Works with 3ds Max 2011-2016
Selected Key New Features
Corona Displacement modifier added, and Displacementimproved in general
Support for 3ds Max Atmospheric effects added
Improved Corona Multimap
1.1 (hotfix 1)
Released on June 16, 2015
Works with 3ds Max 2011-2016
Selected Key New Features
Corona Bitmap added, giving speedups
Improved support for Particle Flow
Improved error reporting
1.0 (hotfix 3)
Released on February 25, 2015
Works with 3ds Max 2011-2016
There are so many renderers available out there, and how does an artist know what to choose? Although they really do the same thing, they work differently and have different results. Here is a breakdown of what the different renderers offer, not reviews, so you can decide which renderer is right for you.