renderman

Deciding to go with renderman gives allows you to tap a large talent pool that are already familiar with Renderman.

Most studios switched away from Renderman as its support for ray tracing was extremely lacking until a year ago.

Cycles shading graph is very limited (but well chosen) compared to the flexibility of Renderman Shading Language.

Show me just one really cool thing that can be done with Renderman and can't be done with Cycles.

Also, renderman has been used in production for decades, so a lot of places have built up large libraries of tricks, shaders or tools that work with renderman that they can use.

Cycles can do most stuff that Renderman (or Arnold) can, but that's not the point.

In theory Cycles can be used to make the same kind of movies Renderman can.

Now that Renderman also support OSL I'm pretty sure we're going to see OSL examples posted online.

As most people thought that Disney was still using RenderMan, people never realized that they were actually using that architecture in a production renderer.

Anyone have any insight as to why Disney would build a separate rending engine when they own Pixar and could use their renderman engine?

For the record, I'll use both, and I am happy to see Renderman as an option.

RenderMan's value is entirely in it's extremely fine level of control.

Renderman has a lot of "scalability" features like caching indirect lighting into brickmaps, or loading large sets of tiled textures, that cycles (or even blender) just don't support.

Sure, Cycles probably doesn't have an implementation of "Portal-Masked Environment Map Sampling" by Bitterli, Novak and Jarosz yet, so I'm sure Renderman is better at it, but Cycles is decent at it.

"Disney uses a mix of Hyperion and RenderMan, as Hyperion is not useable for test renders, as it can take up to 15 minutes until a pixel will appear on the screen, as they trace millions of rays at the same time." None of the things you claim in this sentence are true.

Renderman produces very good motion blur without much performance hit, which is critical for integrating with real-world footage.

If you Google it for a couple minutes, you'll see why a lot of people would prefer Renderman.

There's 30 years of history showing off Renderman, and everybody in the CG industry knows that it's awesome.