Object ID/mat ID/Vray Effect ID.... in viewport?

Hello,
I’ve been looking for a while regarding a script to display in the viewport the ID render element (material ID, Object ID, vray effect ID, multimatte…) but without success.
In case you know a trick to avoid to render to get such ID visible in the viewport, thanks to share.

Of course, because they are Render element, they are not supposed to be visible in the viewport, but I’m not a specialist,so…

the simplest way would be to collect all the relevant data (IDs and such), and then script-map them to a wirecolor for each object.
You would run into a number of limitations, however (such as with multimattes, where each has just three, anti-aliased colors per RE), and of course there is no guarantee that the colors you generated for the VP display would match those of the renderer (in fact, they most likely will not), so you’ll have to stick the the viewport-generated content, for post, as it won’t be very easy (or rather, it is. it’s just quite laborious!) to match what the renderer outputs.

The complex way would be to code a texture map (perhaps some hackery with either GLSL or OSL may suffice. If they read stuff like IDs, that is.) which would somehow query VRay to find which color the ID will be once rendered (if that’s at all possible.), and then simply display that.

Thanks Lele.
Seems that I’m the only one that need such fast responsive workflow. So I probably miss something that other vray user used without problem. It’s very easy to forget to assign the good number or channel ID…or I’m the only one to be lazy!

I believe that it is more something that must be develop into 3D max core, than a script.

If you want, be more specific as to the workflow you’re trying to achieve, and i will at least try and share the way *I* would go about it (that is to say, it’s just one of the many ways to skin the same cat…).
I can tell you that the one thing i NEVER did by hand, as a rule, while working in film, was to manually assign IDs.
Scripted tools would take care of that, based on a number of different heuristics on the scene.
And the same would happen in post (for they have to figure stuff out after the fact…).