Raytracing today and in the future

By Jon Peddie

More papers, patents and PhDs have been written and awarded on ray tracing than any other computer graphic technique.

Ray tracing is a subset of the rendering market. The rendering market is a subset of software for larger markets, including media and entertainment (M&E), architecture, engineering and construction (AEC), computer-aided design (CAD), scientific, entertainment content creation and simulation-visualization. Not all users who have rendering capabilities in their products use it. At the same time there are products that have been developed solely as rendering tools and there are products that include 3D modeling, animation and rendering capabilities, and they may be used primarily for rendering, primarily for modeling or primarily for animation.

Because ray tracing is so important, and at the same time computationally burdensome, individuals and organizations have spent years and millions of dollars trying to speed things up. A typical ray traced scene on an old-fashioned HD screen can tax a CPU so heavily the image can only be upgraded maybe every second or two — certainly not the 33ms needed for realtime rendering.

GPUs can’t help much because one of the characteristics of ray tracing is it has no memory and every frame is a new frame, so the computational load is immutable. Also, the branching that occurs in raytracing defeats the power of a GPU’s SIMD architecture.

Material Libraries Critical
Prior to 2015, all ray tracer engines came with their own materials libraries. Cataloging the characteristics of all the types of materials in the world is beyond the resources of any company’s ability to develop and support. And the lack of standards has held back any cooperative development in the industry. However, a few companies have agreed to work together and share their libraries.

I believe we will see an opening up of libraries and the ability of various ray tracing engines to be able to avail themselves of a much larger library of materials. Nvidia is developing a standard-like capability they are calling the Material Definition Language — (MDL) and using it to allow various libraries to work with a wide range of ray tracing engines.

Rendering Becomes a Function of Price
In the near future, I expect to see 3D rendering become a capability offered as an online service. While it’s not altogether clear how this will affect the market, I think it will boost the use of ray tracing and lower the cost to an as-needed basis. It also offers the promise of being able to apply huge quantities of processing power limited only by the amount of money the user is willing to pay. Ray tracing will resolve to time (to render a scene) divided by cost.

That will continue to bring down the time to generate a ray traced frame for an animation for example, but it probably won’t get us to realtime ray tracing at 4K or beyond.

Shortcuts and Semiconductors
Work continues on finding clever ways to short circuit the computational load by using intelligent algorithms to look at the scene and deterministically allocate what objects will be seen, and which surfaces need to be considered.

Hybrid techniques are being improved and evolved where only certain portions of a scene are ray traced. Objects in the distance for example don’t need to be ray traced and flat, dull colored objects don’t need it.

Chaos Group says the use of variance-based adaptive sampling on this model of Christmas cookies from Autodesk 3ds Max provided a better final image in record time. (Source: Chaos Group)

Semiconductors are being developed to specifically accelerate ray tracing. Imagination Technologies, the company that designs Apple’s iPhone and iPad GPU, has a specific ray tracing engine that, when combined with the advance techniques just described can render an HD scene with partial ray traced elements several times a second. Siliconarts is a startup in Korea that has developed a ray tracing accelerator and I have seen demonstrations of it generating images at 30fps. And Nvidia is working ways to make a standard GPU more ray-tracing friendly.

All these ideas and developments will come together in the very near future and we will begin to realize realtime ray tracing.

Market Size
It is impossible to know how many users there are of ray tracing programs because the major 3D modeling and CAD programs, both commercial and free (e.g., Autodesk, Blender, etc.) have built-in ray tracing engines, as well as the ability to use pluggable add-on software programs for ray tracing.

The potentially available market vs. the totally available market (TAM).

Also, not all users make use of ray tracing on a regular basis— some use it every day, others maybe occasionally or once a project. Furthermore, some users will use multiple ray tracing programs in a project, depending upon their materials library, user interface, specific functional requirements or pipeline functionality.

Free vs. Commercial
A great deal of the raytracing software available on the market is the result of university projects. Some of the developers of such programs have formed companies, others have chosen to stay in academia or work as independent programmers.

The number of new suppliers has not slowed down indicating a continued demand for ray tracing

The non-commercial developers continue to offer their ray tracing rendering software as an open source and for free — and continue to support it, either individually or as part of a group.

Raytracing Engine Suppliers
The market for ray tracing is entering into a new phase. This is partially due to improved and readily available low-cost processors (thank you, Moore’s law), but more importantly it is because of the demand and need for accurate virtual prototyping and improved workflows.

Rendering in the cloud using GPUs (Source OneRender).

As with any market, there is a 20/80 rule, where 20 percent of the suppliers represent 80 percent of the market. The ray tracing market may be even more unbalanced. There would appear to be too many suppliers in the market despite failures and merger and acquisition activities. At the same time many competing suppliers have been able to successfully coexist by offering features customized for their most important customers.

Conclusion
Ray tracing is to manufacturing what a storyboard is to film — the ability to visualize the product before it’s built. Movies couldn’t be made today with the quality they have without ray tracing. Think of how good the characters in Cars looked — that imagery made it possible for you to suspend disbelief and get into the story. It used to be: “Ray tracing — Who needs it?” Today it’s: “Ray tracing? Who doesn’t use it?”

Our Main Image: An example of different materials being applied to the same object (Source Nvidia)

Dr. Jon Peddie is president of Jon Peddie Research, which just completed an in-depth market study on the ray tracing market. He is the former president of Siggraph Pioneers and  serves on advisory boards of several companies. In 2015, he was given the Life Time Achievement award from the CAAD society. His most recent book is “The History of Visual Magic in Computers.”

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