3D Terminology

Think of the central processing unit, or CPU, as your computer’s brain and control center. A graphics processing unit, or GPU, is there to render 3D graphics and to help the CPU perform its calculations. The CPU is based on single cores so it works on one bit of data at a time. The GPU is designed for parallel processing so they can work with a lot of data simultaneously. To sum it up, a quote from Kevin Krewell from Nvidia explains it well: “Architecturally, the CPU is composed of just a few cores with lots of cache memory that can handle a few software threads at a time. In contrast, a GPU comprises hundreds of cores that can handle thousands of threads simultaneously.”

Some 3D renderers will utilize the GPU instead of the CPU, which can mean faster renders, but the downside is that GPUs are limited to the amount of VRAM or video memory. Many renderers are hybrid and use both the CPU and GPU.

GPU vs. CPU Video Rendering and Video Editing

Roberto Blake gives an excellent overview of whether you should choose GPU or CPU rendering.

Global Illumination is the algorithm that the software uses to recreate natural lighting from the real world. There are several types of algorithms such as radiosity, ray tracing, beam tracing, cone tracing, path tracing, Metropolis light transport, ambient occlusion, photon mapping, and image-based lighting. Even more, these can be used on their own or in combination with each other to create better results. [Source: Wikipedia: Global Illumination]

C4D Fundamentals | 07 – Advanced Rendering – Understanding Global Illumination

While this video is targeted to Cinema 4D, much of the information applies to any other 3D software.

This is a common algorithm for photo realism used by 3D software and it seems to be tied in with probability in gambling! To explain, “Monte Carlo methods are also efficient in solving coupled integral differential equations of radiation fields and energy transport, and thus these methods have been used in global illumination computations that produce photo-realistic images of virtual 3D models, with applications in video games, architecture, design, computer-generated films, and cinematic special effects.” [Source: Wikipedia: Monte Carlo method]

Further reading:

• Monte Carlo methods for improved rendering – This is an academic paper from the Institute for Applied Computational Sciences, Harvard School of Engineering and Applied Sciences.

Embree, developed at Intel, is a collection of high-performance ray tracing kernels. Hence, it is explained in the video below from Intel.

Many renderers use Embree ray tracing kernels. In addition, V-Ray Next includes a custom Embree ray tracing library “which speeds up anything from proxies to motion blur.” [Source: Interview: V-Ray Next and the Future of Rendering – CG Channel] FluidRay RT, Corona Render, and others also use it.

Further reading:

• How Embree Delivers Uncompromising Photorealism | Intel® Software
• Download Embree here
• The Embree Example Renderer – This is a photo-realistic path tracer that builds on the Embree high-performance ray tracing kernels (Note: not a full-featured renderer and not designed to be used for production rendering)

Finally, Physically based rendering, often abbreviated as PBR, uses mathematical theories that allow for photorealistic renderings.

What is PBR? Physically-Based Rendering Explained

Further Reading:

• Physically Based Rendering From Theory to Implementation, Second Edition, by Matt Pharr and Greg Humphreys
• Basic Theory Of Physically-based Rendering
• PBR Guide from Allegorithmic – Wes McDermott and his friends at Allegorithmic have updated The PBR Guide. It’s a 2 volume guide to physically based rendering. In order to keep pace with evolving 3D technology, they are keeping the information and techniques in the book up to date. Of course, it’s available as a free download on Substance Academy.
• Maya Monday: How Physically Based Rendering Shaders Work
• Webinar Replay: NVIDIA: Transform Your Workflow with Physically Based Materials