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can i use the id matte effect with files from max?
hey guys,
did a quick search but nothing came up.
just wondering if it is possible for my 3dsMAX guy to export a file with all object ids, so that i can use the id matte effect (under 3d channel operations) to pull a matte for any object i like, rather than having to request renders of individual mattes each time i need them. this would be a huge timesaver for everyone.any suggestions?
i’ve heard that combustion can do the same thing (i use combustion here too). so if it’s not possible with 3dsmax+afx, does anyone know if it’s possible with 3dsmax+combustion? i shall post in that forum too.thankyou!
scott. -
3 Replies
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surely you can.
what you need to do is just to render your footage into .rpf files,then add a ID Matte filter for them in AE.****************************
I love After effects! -
I found it kind of tricky to do in after effects, the matte filter itself has a slider for the channel you want to matte and it’s hard to tell what the id number is to select, combustion has a nice picker that lets you click on a couple of pixels of the object you want to remove and it works, also the show G-Buffer filter is usefull for checking what 3d channels are in your render, in combustion it colours them brightly but in after effects (extract 3d channel effect)it’s usually a very low contrast greyscale, it might look completely black but if you tweak or use auto levels you’ll see the different channels, I don’t know how the colours relate to the object id’s though however which is the problem.
Remember that the matte won’t be aliased, the “Use Coverage” checkbox will improve the edges if your render included coverage, otherwise you could choke the matte or use the feather option, for a couple of projects we rendered at double the resolution to improve the results. I love after effects and it’s my main workhorse but I usually find combustion handles 3d channels and rpf’s better.
You might look into using a “Pure Colours” pass as a trick to get multiple mattes from the same render, it was shown to me once and is a cool trick but right now I don’t know how to explain it or point you to an explanation, basically you render from max with objects containing 100% colours which you can then matte out like a key, you render to RGB but use it for mattes only along with your real RGB render. (You can leave all your lights and textures off generally for the pure colours pass to speed up your renders)Glenn Stewart
1k Studios -
similar to what you say, but also kinda, different, at the moment some of the 3d guys render 3 or four mattes into one file, and we take a single channel (r, g, b, or a) for a matte. but that doesn’t cover all objects in a scene, so i was looking for a way to have the 3d render one file (or sequence) and we’d be able to pull any matte we wanted from it.
will look into combustion more, since as above it states there’s no aliasing on the id matte. 🙁
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