Clown Pass?

[blueskydesigngroup]

Wondering if anyone has any script (or if I'm missing an existing feature) to render the scene with objects assigned random emissive colours?

The final render is a rainbow-like (but flat, no reflections/shadows) image making selection of various parts of the scene easier to select in Photoshop with the magic wand tool.

In Keyshot the feature is called a clown pass https://www.keyshot.com/keyshot-rend...-render-layers. I've been doing it manually in Vray for years. Sometimes you need individual surfaces to be unique colours to be able to select finer areas etc. so automating the process isn't necessarily ideal, but in some complex scenes it would certainly be quicker.

Am I missing such a feature in Vray for Rhino? Does anyone know of a script? You'd think you could run a script that says 1. select object #1 2. assign random material (from a pool of say 12 emissive materials) then object+1 and repeat?

[Micha]

A workaround could be you ask at the Rhino forum for a script that assign diffuse colors to objects per rhino materials and you render the diffuse channel output.

[blueskydesigngroup]

Hi, thanks for the reply!

Ok so rather than use vray at all, have the rhinoscript assign standard rhino materials... I wonder how that could be achieved with objects not having unique names? Like is there a list of objects that the script can access to run the loop through?

I guess questions for the rhino forum

[mnewberg]

Do you use this "Clown Pass" in post processing work afterward, or do you just send it to the clients as is?

[blueskydesigngroup]

Purely for post production in house.

[mnewberg]

How would this be different from Material ID output channel? What is the benefit of the color mapping vs Material ID?

[blueskydesigngroup]

Because for instance... if you have two completely separate objects which have the same materials applied but are one behind the other in your viewport, they'll render in the same colour and selecting one object is not possible.

I tried RenderID though which is actually exactly what I needed! I can take an object, explode it and on the RenderID channel every surface gets a different colour. Perfect.

It'd get interesting with thousands of surfaces in the scene, probably a bit counter intuitive but certainly a lot quicker than doing this manually.

[blueskydesigngroup]

So it turns out the result is rather badly aliased with RenderID. From what I've read it's because it's an integer value and not floating point.

Any ideas on if this can be corrected anywhere in the vray settings?