1) Would be nice to have an option for by “Material”. This is useful in cases (mostly always) where we need to render ONLY glass for example. Why not just set IDs for glass or stick it on its own layer you may ask? The answer is simple. In archviz, the turnaround is often very fast and we work on LOADS of 3rd party models and models from clients. Glass are hardly EVER on its own, instead its usually a single object part of doors, windows etc. It’s rediculous to detach all the glass from hundreds (sometimes thousands) of objects just to stiuck it on its own layer or give it its own id.
So typically you would have a multisub with 4 or 5 vraymaterials, and any one of those can be the actual glass material. We would then use that glass material as the mask.
2) In addition to this, it would be nice to exclude thigns from rendering, by material also. So if we want to switch off the glass or hide it, we can do it by material instead of hiding the entire door, window etc
Erm, the Multimatte has support for material ID’s since it’s introduction well over a decade ago… Simply check the “is MatID” checkbox and set the ID’s for your materials in the Material Editor. Sadly, the editor only allows for ID’s up to 15, but you can set any number with a script command.
Unfortunately there’s nothing new related to render masks and materials in Next 1.2
Generally doing render mask by material is something users have asked for a while but there are difficulties that I’m not sure how we can solve. Doing it for simple materials is not overly difficult but then the question is about complex materials like multisub or blend materials. Multisub materials might be doable but will slow things a bit. Blend materials on the other hand are even more complex - if only one of the materials in the blend is in the render mask we’ll need to calculate the blending weights - something that could be slow and require many additional calculations (for example if the different blend amounts are determined by some complex dirt textures..). Then what should we do with the other materials part of the blend but not part of the mask - shade them too or treat them as black..
Overall I’m not sure the end result won’t be similar in time to rendering the whole image again..
Granted, as I hit post I got what you are asking for
As pointed out it would be tricky for materials like glass where a lot of the look of it is down to what is reflected and refracted. If you took those out, what would you be left with? Probably wouldn’t look like glass and would require a whole lot of post work to look right.
It’s irrelevant if it’s easy or tricky to code the solution, that’s what we’re paying for isnt it? I’d like to think there’s more than enough smart people at Chaos that can figure it out.
Also, I said glass in the example, but it can be mirrors, or anything else really
To me, if the material has any kind of refraction, it should also render what you see behind it. Same as the render mask “selected” currently works. So if I have glass as the material mask, it would render the same asif glass is seperate objects and render whatever you see through it
