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primvars: send vales from unity to octane

PostPosted: Sat Aug 24, 2019 4:21 pm
by mathaig
Heavy one: I was wondering if there is any equivalent to Renderman primvars in Octane. I will explain:

Lets say that I have a model of a brown cat. In my shot I would to have 5 cats, but with different colors, not just brown .
The traditional way to do this is to duplicate the asset, duplicate the shader, change the color in the shader then assign it to the new cat. Repeat this process 4 times to make 4 more assets, thereby making the scene heavy. Technically 4 times more memory occupied, more assets to manage.

In renderman, primvar allows you to send data from host DCC to the renderer. The above example can be efficiently executed by creating a primvar color variable to the shader, then overriding the default color value with the primvar variable. So when you define the primvar color on the particular instance in the DCC, there renderer reflects this change. This is brutally efficient.

I wonder if you have such feature in development ?


Re: primvars: send vales from unity to octane

PostPosted: Fri Aug 30, 2019 1:47 pm
by ChrisHekman
Primvars are not supported. However, reusing the model 4 times will not duplicate your model data 4 times. We reuse models.
Which means that you could create multiple materials, one for each of your cats.

Re: primvars: send vales from unity to octane

PostPosted: Wed Sep 04, 2019 8:56 am
by mathaig
Thank you for the response, but i think I have not explained myself very much.

How can I drive an octane shader parameter from unity ? For example, if i used a Mix shader, how can I drive the blend from unity ?