DreamWorks Animation announced their intent to release their proprietary production renderer, MoonRay, as open source software later this year.  The studio’s state-of-the-art Monte Carlo Ray Tracer has been used on feature films such as How to Train Your Dragon: The Hidden World, Croods: A New Age, The Bad Guys and the upcoming Puss in Boots: The Last Wish.

The Technical Details

MoonRay was developed by DreamWorks’ world-class engineers, and includes an extensive library of production-tested, physically based materials, a USD Hydra render delegate, multi-machine and Dreamwork’s cloud rendering framework, called Arras.

In layman’s terms, this basically means that Dreamworks is releasing its entire rendering pipeline as open source, not just the rendering engine itself. The ramifications are that anyone will be able to use MoonRay in production, using only the pieces they need and have the hardware to power.

MoonRay is a ray tracker, which means that instead of tracing every ray of light through the scene from the the scene back to the light sources, the rendering engine only renders the most likely paths. This makes it a ton faster, and culling the less likely paths is undetectable to the viewer. The results are just as gorgeous as a full ray tracer would have been. The discarded paths, the ones that are skipped over, don’t contribute as much as you’d think.

MoonRay uses a Monte Carlo method for skipping across surfaces and rendering only samples of the surfaces instead of every subpixel possible. It’s a lot faster to do that and average the results. The combination of the two techniques makes MoonRay super, super fast without sacrificing image quality.

A sample image created with MoonRay, showing reflection, refraction, caustics, and object occlusion.

Dreamwork’s MoonRay renderer is a lot younger than Pixar’s Renderman, the rendering engine which until recently has been the best in the world in terms of power and flexibility. The MoonRay project was begun ten years ago, and they designed it with modern technology for threading, parallelism and task distribution.

The translation: it works really really well on a grid. You can harness a pod of slave computers to all work together on rendering a frame, and watch it resolve at full cinema-grade resolution before your eyes in seconds. This makes the various tasks involved in creating scenes much much faster, and require far fewer iterations to get things right. The artists can see what they’re doing in near real time.

Additional high-performance features include support for distributed rendering, a pixel matching XPU mode that offers improved performance by processing bundles of rays on the GPU as well as the CPU, ray processing via Intel Embree, shader vectorization utilizing Intel ISPC compilation and bundled path tracing. MoonRay includes a USD Hydra render delegate for integration into content creation tools that support the standard.

They’ve been working closely with Intel’s Advanced Ray Tracing division to make this thing fly. The hair and fur rendering system uses the same math as Renderman’s does, and the same as the in-house renderer that Rhythm & Hues had developed: the Kajiya shader system, which bounces light in and out of virtual hair filaments to produce anisotropic reflection, the effect of rendered hair that makes it actually look like hair.

MoonRay is also cloud compatible, which means that studios can work in real time in a distributed format, with adjuncts and facilities around the globe.

Where to Get It

DreamWorks intends to make MoonRay available under the Apache 2.0 license. Further information and updates will be available at OpenMoonRay.org. There is no timeline on the release of MoonRay yet, nor how many production packages with which it will be compatible. We’re guessing at mininum they’ll do setups for Maya and 3dMax, and if they’re smart they’ll do Blender as well, since by far the most 3d artists below the professional line use that rather than the more expensive counterparts. The CG artists of the future have to come from somewhere, and excluding Blender from the party will hobble Dreamworks’ goal of creating a new generation of employable artists who have background in MoonRay on date of hire instead of having to take months to train them up properly.

A Pivotal Moment

The MoonRay rendering system changes the playing field for everybody. By releasing it as Apache GPL 2.0 (GNU Public License), they’re allowing anybody with the technical resources to use it the right to do so on their own projects, commercial or otherwise. This is a huge benefit to small and independent productions that might otherwise have to include Renderman licenses in their budgets, or pay for time on a render farm that has to carry those expensive licenses as part of their services. I predict that there will be a massive shift toward MoonRay because of this.

Pixar’s Renderman will continue to be used, but competition has gotten pretty intense, and you’ll see it used in professional production somewhat less because of that. Still, entire generations of CGI artists cut their teeth on Renderman, and they have that “first to market” advantage.

There are a lot of other rendering engines out there, each with their strengths and weaknesses, but nearly all are paid license systems.

Cyles X, however…

Blender, however, has more than one option for a free rendering system, and have certainly not been standing still. Their relatively new rendering engine Cycles X is nearly as feature rich as Renderman is despite having been around for only about a year and a half, and has the distinct advantage of being free, as in beer. Render farms that use Cycles don’t have to pay core licenses to use it, and as a result Blender render farms are vastly cheaper (and sometimes free). It compares favorably to MoonRay in terms of speed and quality, and already has a good head start.

What you see in the video below is on a single PC with no cloud of CPU cores assisting with the ray tracking tasks. Cycles by itself already compares favorably with MoonRay, but Cycles X, with its RTX GPU support, is blazing fast. Playing the devil’s advocate for a moment, Blender with Cycles X may be the better choice for small CG shops or small team animation projects. MoonRay and its constellation of grid computing pipeline software might be the better choice for larger productions, or for artists who hope to work at Dreamworks some day.

Cycles X is in Blender 3.0, and is just called “Cycles”. “Cycles X” was the name of the new version of Cycles while it was in development — and that brings me to the main drawback to Cycles. While there is a standalone version of the Cycles renderer, the last time anybody was working on a Cycles for Maya plugin was 2018. The plugin might work, but since nobody’s maintaining it, if it ever breaks, you’re on your own.

Compare this to the demo video of MoonRay, and remember that this works on a single computer with an NVidia GPU, whereas MoonRay needs a grid cluster to get the same performance. Cycles is nearly as powerful and is a ton faster. The downside? Cycles is Blender only, and incompatible with the Autodesk Maya world.

The main note here, I guess, is that while MoonRay is probably insanely powerful and handles things like caustics and reflections in a fully proper way, you can go through your whole career and never hit that particular problem. In the meantime there are other free rendering systems that may come along and drink MoonRay’s milkshake on this. The downside, of course, is that Cycles only works in a Blender-driven pipeline.

The fact that MoonRay is going open source is a sign of tremendous volatility in the CG animation arena, and while very cool by itself — impressive move, Dreamworks — the ramifications to both the business and the art of computer animation are far greater than a single software release.

About Dreamworks

A division of the Universal Filmed Entertainment Group, within NBCUniversal, a subsidiary of Comcast Corporation, DreamWorks Animation is a global family entertainment company with feature film and TV brands supported by a robust, worldwide consumer products practice. DWA’s feature film heritage includes  beloved characters and franchises such as Shrek, Madagascar, Kung Fu Panda, How to Train Your Dragon, Spirit, Trolls, The Boss Baby and 2022’s The Bad Guys, which have amassed more than $15 billion in global box office. DreamWorks Animation’s award-winning original TV content reaches consumers in more than 190 countries.


Gene Turnbow
Gene Turnbow

President of Krypton Media Group, Inc., radio personality and station manager of SCIFI.radio. Part writer, part animator, part musician, part illustrator, part programmer, part entrepreneur – all geek.