Multimatte material ID's

[vance3d]

I have been experiencing a problem with multimatte in which setting multimatte to generate mattes based on material ID's does not work as expected.

If I set faces of an editable poly with unique material ID's and then set multimatte to work with these id's I get no mattes.

When I set material ID's in the material itself using what was in the past called the material effects channel but now just seems to be called material ID, it works.

Is this result correct or is it a bug?

this is using vray 2.00.02 in max 2011

Thanks,

V Miller

[greysheep5]

if you check the "matID" tickbox in the multimatte, then yes of course, it uses the id´s set in the material editor.

that´s the way we work with multimattes, in our case this makes sense so we can adjust every material seperately in the post processing phase. but i have to confess i haven´t used it in any other way, so no tips how else it should work.

best regards,

christoph.

[joconnell]

As far as I know the actual matte channels are based on the materials being assigned themselves, rather than the poly assigned id's. So for example, if you have an object with no material assigned and you give it material id 1,2 & 3 in it's polygon properties, it doesn't generate any information for vray to make a matte from. If you make three vray materials with material id 1, 2 & 3 and assign them to the object, it does give vray enough to make a matte. The multimatte gets it's info from the shader properties and not the object itself.

[vance3d]

Ok I think that the naming of these distinct features needs to modified since they are nearly identical and do different things. I haven't used the Material ID channel in the material editor for quite some time. I use the Material ID's all the time and expected that was what multimatte was looking at since the check box is titled MatID and not MatID Channel.

I've never come across this problem before because I usually use Object ID's in multimatte.

thanks for the clarification.

V Miller

[plastic_]

The multimatte doesn't use face material id's.
It uses either material id channels, set in the material editor, or object id, set in the object properties.
In order to use face material id values you have to assign a multi/sub material with different material id channels.

(edit: sorry missed the previous answer by joconnel)

[joconnell]

Tag team

[vlado]

Or a VRayMultiTex with different colors for each ID...

Best regards,
Vlado

[joconnell]

That's sneaky - I wasn't aware of that one, that'll come in very handy!

[vance3d]

Thats clever. will definitely use that.