Exporting variable from SHOPS

[silkey]

Hi there

Please forgive my noob status but is there some way of passing variables from a shop node (material shader builder) back up to sops level to evaluate in the node structure?  I have tried bind export but no dice.

 

Thanks in advance.

[davpe]

you can't. rendering networks can't manipulate it's own input. if you think about it, before you actually push the render button, you have no data generated by SHOP network (so there is nothing to pass). after you start the render, geometry, lights, etc. are loaded and some math is performed. at the end, resulting data that only exist temporarily in RAM are saved as an image and memory is wiped. so there is no way to affect original geometry this way.

what you can do is to uv bake your render to an image and use the image to manipulate geometry (transfer attribute or whatever). result will be, of course, limited by the geometry resolution.

[silkey]

Thanks Davpe.

I get it, it was to see numerical levels of displacement prior to render but I can see now that logic prevents it.  I picked up a tip on Matt Estella's webinar last week where he suggested building systems in vops first and it worked out to be the answer.

[davpe]

oh I see. building systems in vops beforehand seems to be quite clumsy for procedural texturing. I'm sure there are other cases where that makes a lot of sense though.

anyway, if you only need to see whats going on at any spot of your shop you can simply define an arbitrary aov for that part of the network. or plug whatever you want to inspect directly into the surface output and render that if you want an instant feedback (this is the method I personally prefer as it seems to be the fastest way).