Rendering Yeti Hair in Pixar’s Renderman

Hey guys,

I have always been intrigued and amazed by the render quality of Pixar Renderman especially when rendering Hair in their films. It looks so polished and beautiful at the same time. After watching Brave I was in complete awe by the way they had tackled Merida’s Hairstyle and Simulation.

So I took up a challenge to do a test trying to understand how Pixar’s Renderman works and how I can achieve a beautiful hair look.

I have been working in Yeti for quite sometime and really like its Grooming tools a lot and have written and integrated many tools in the pipeline to get the best results from Yeti Hair System. So I am going to do a quick test and show you guys how to work in Yeti and render it in Pixar’s Renderman.

Firstly we will need to install Yeti and all the information needed for that is provided on the software website. Next step is loading the Yeti plugin in Maya.

After loading you should have the Yeti shelf load as well.

Next step lets create some hair :D. Firstly we will need to create Yeti Node on the mesh we need the hair and then create Yeti Groom to then stylize and comb the hair as we like. So I always liked the hair on Horse’s neck and it could be really nice challenge as well.

Now for Renderman you can get an Non-Commercial version from Pixar website and it’s very easy to download and install it and next let’s also load the Renderman plugin as well.

With loading Renderman you should get the shelf and all button related to that as well.

Now let’s start to Render but before that we need to do the most important step. If you just click render, the Yeti Hair will not render at all because we need to configure the RMSWorkspace.ini in the Renderman folder. For Window’s especially we need to do a little bit of changes in that file.

Look for “SetPref WSSearchPaths.procedural” in the file and adding the yeti location path like the following:

SetPref WSSearchPaths.procedural \
[list \\\${RMSTREE}/lib/plugins \\\${RMANTREE}/etc @ {C:/Yeti/bin}]

This will let Renderman know that we are using Yeti as the Hair system and thus it will recognize all Yeti nodes created in your Maya file.

After the hair is created we need to start the setup for Renderman, firstly let’s add the shader needed for the hair. Renderman has a built-in hair shader called “PxrMarschnerHair”. Use this as a base start and then play around until you like the results.

(Quick Tip: Use the IPR button in Renderman shelf to create a live Render thus all your changes can be seen in Real-time.)

And for a quick lighting, use the 3-point light rig from the preset browser of Renderman, it should suffice for any test needed regarding hair tests.

So here are some of the test renders.

Played with some width attribute in Yeti.

Well I am really interested in learning Renderman now and will keep digging deeper into it even though I am not a Lighter but I really like the Technical aspects of it and also learn to write Shaders using RSL (Renderman Shading Language).

Until next time.

#vfx #vfxartist #art #blog #blogging #python #maya #mayaapi #vertex #api #technical #rigging #creature #animation