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kirtap
02-14-2005, 08:15 PM
I have bump i want to add to a specific area of a surface. I have maps i am using for specularity and reflection and they are the same as the area i want to be bumpy. I used to know this but apparantly forgot. Basically i want my file to say, "use fractal over here but not here". Please help i'm sure it's simple.

Thanks

jbo
02-14-2005, 08:37 PM
there's a whole bunch of ways you could do that...
one way, is put a fractal on everything, then convert it to a file texture, then open it in photoshop and make the areas you don't want bumpy 50% grey.

another way is to use a surface shader... you make two seperate materials, one for bumpy, one for not bumpy. then you paint a greyscale mask that determines where each material gets applied. then you use a blend node to combine the two, using your mask to determine how, and have that go into the out color attr of the surface shader... sorry, i don't have maya in front of me at the moment, so that might not be 100% accurate.

another way is to have a layered shader. again make two seperate shaders and a mask... then just use the mask in the transparency attr of whichever one you put on top in the layered shader. the difference in doing it this way is that the specular will remain on areas that are transparent, so you should use a lambert or something for the bottom layer, otherwise you'll get double specular in some places.

there's probably a whole bunch of other ways to do it, if you don't need a smooth transition, you could just select some faces of your object and apply one material to them and then select the other faces and apply the other material to them.

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