Renderman RIS v. Cycles Comparison

There has been a lot to digest with Pixar releasing PRMan 20 with a free version. Several people mentioned that Renderman is head and shoulders beyond cycles. In my (very limited experience) PRMan has some advantages, but Cycles isn’t hopelessly in the dust as some have claimed. I have used Cycles for my first semi-professional level project and found it to be quite adequate.

If you were to make a top 3 or top 10 list of areas where Cycles lacks features altogether or is far behind PRMan (or Arnold, etc) what would you put on it?

I will likely be using Cycles for the foreseeable future given the success I’ve had with it. But I’m curious to get a well-rounded view.

PRman is a production renderer, Cycles is geared towards hobbyists and small studios by design. Instead of looking at “which is better”, you should focus on which is adequate for the tasks you want it to do. What’s really important is for Blender to be able to support all the major rendering engines out there so that people who use them don’t have to dismiss Blender as a whole.

  1. The texture handling. No greyscale or RGB maps, no mipmapping, no tile cache. Cycles wastes a horrific amount of memory and startup time loading texture data that isn’t needed on the current frame. Sure, if you’re only doing one image you can optimize around that, but if you have multiple cameras or an animated camera? Forget it. Cycles is loading every texel for every angle and frame every time and there’s nothing you can do about it.

  2. Deformation blur is way slower than it should be. Especially with hair.

  3. No render-time displacement or render proxies, so all polys in the scene need to be passed through Blender in one big pile. On every render startup. Render proxies can allow you to pre-cache export for big static objects like trees, background vehicles, etc. Instead of taking the time to update and export what ends up being the same mesh every time.

Not that the Cycles devs don’t know about any of these, they’re well aware. It’s just an issue of dev time to get around to them. But if you wonder what these other renderers like PRman and Arnold have to deal with giant scenes, it’s stuff like this.

That’s the kind of thing I’ve been hearing, that Cycles isn’t on par with a production renderer, but without specifics I have no way to evaluate that. In other words, being used by a big production company doesn’t make a renderer good. There must be specifics that make the renderer good.

For instance, at one point PRMan and REYES were the only feasible way to render a scene with complicated geometry because the displacement scheme allowed for small memory footprints. Now that PRMan has moved to RIS, like Cycles and Arnold, that isn’t an issue - and even before that wasn’t an issue since hardware raced forward. Now I would guess that memory usage for large scenes is roughly equivalent, and that you can just buy a ton of RAM if you need that.

I can imagine ways that Cycles might not stack up to a given production renderer, but I don’t have any specifics to back those up:

Pipeline - existing tools work with it and people know how to use it. This is probably the hardest one for Cycles to make inroads.

Visual Quality - the end result is the best it could possibly be.

Speed - getting the visual quality faster saves time and money.

Flexibility - You can do anything you want. I think this is also on area where Cycles may be behind a typical production renderer.

Thanks J_the_Ninja. That is helpful. So mainly these issues are with performance, especially large scene performance.

I tested the Goosebery benchmark on the Quadro M6000 with 12go of ram, Blender crashed.
So cycles for big production can not be used with CG’s.

So whyle you are only CPU, what will you choose to render yours images ? Cycles who is really young and not finish or Renderman who has a great support and a ton of movies made with it ?

I love cycles and I use it for professional and personnal work, but I cannot use it all the time.
Right now I’m working on a projet on guerilla because I cannot render it on cycles.

We have to choose the good render engine for our projects and this is cool that we have the choise.

I hear that renderman’s speed at massive scene sizes comes at the expense of being quite slow at simple scenes (though I think the denoising would help with that a bit).

This is good for producers, but less so for hobbyists (who are unlikely to make such massive scenes due to the limits of desktop hardware).

Renderman and Arnold both masters of utilizing memory. They can also handle hair and motion blur really, really well.

Arnold have more features for VFX though (like a shadowcatcher material) while Renderman just offers more control over the low-level technical stuff.

There seems to be a recurring theme amongst many blender users here concerning renderman. So many of them are almost hostile to the thought of people wanting to use Renderman instead of Cycles.

Don’t worry guys. Renderman isnt going to somehow supplant cycles. The dev team isn’t going to throw their hands up in defeat and cease their work on Cycles because Renderman muscled onto their turf.

Renderman is a HUGELY WELCOME addition to the available renderers for Blender. And if it does not meet your needs, that’s ok. Cycles is pretty awesome, especially for smaller productions.

J-The-Ninja hit some of the key areas where Cycles falls on it’s face. If you hit these walls on your production, the availability of renderers like Renderman may allow you to finish your project in Blender instead of facing the very real possibility of having to finish your project in another app, or just fail at delivery altogether.

For god’s sake, Blender is getting OFFICIAL support from f**king Pixar. We’ve been dreaming about Blender getting some support from Hollywood for years. So be happy and supportive! Cycles will still be there for those that want it, and it’s improving all the time.

nope you’re wrong - cycles supports these features


Hmm. Please continue. :slight_smile:

Pretty sure it’s a monster setup with nodes as a workaround, happy to be proven wrong

:slight_smile: no workaround needed just turn osl on and convert your textures to *tx - done

I’m actually not very familiar with .tx. What software converts to .tx? I did a quick google search and the only thing I found was info on an Arnold utility for converting files to TX, but I don’t have Arnold. Please keep elaborating. Thanks!

So you have to use CPU rendering to use those features, so it’s better to use renderman ^^

Seriously, both render engines are great, no need to compare, we can use both and Renderman should have GPU rendering !

I found some info here:

its a tiny command line tool (im on linux don’t know about windows)

you can use this tutorial ->

I’ve tried a few settings (tiles size etc) but nothing major happens…
so it’s fine to use the arnold setting


on thing you will notice its 2-4 times slower then cycles (super fast!) svm implementation…
only use it if you really need the memory

That’s really interesting, unfortunately OSL is really slow compared to SVM. Have you run any test you can show? (memory usage and so on…)

Renderman has amazing displacement mapping which Cycles dosen’t have - that dosen’t make Cycles a ‘crap’ renderer though.

Use what you are comfortable with and works for you.