Bonedaddy
01-10-2004, 06:19 PM
Hey all,
I've recently been texturing a hill, using displacement maps to create extra details in the rock face. I'm using a procedural shader, and I've tweaked the scaling until I've ghot the right sort of striation in the rock. It looks great, all is well and dandy.
However, I want to be able to tell it where to displace and where not to displace. Basically, I don't want it to displace on flat surfaces, where there are supposed to be roads and houses. To this end, I've made a b&W TGA "displacement mask" that fits fine on the hill.
My basic thought was to multiply the displacement mask by the procedural, so that where the displacement mask is black (i.e. zero), the total displacement would amount to zero. But that isn't what's happened.
What's happened is that the procedural texture doesn't subdivide the same way it does when it is acting without the mask. In fact, it provides radically different results. I'll try and post some renders in a couple days (when I am back near an FTP server I have access to), but essentially, the unfettered procedural produces nice results, the fettered one makes a very CG-looking, unnatural result. You can actually see the pattern of the procedural. It looks awful.
Far as I can figure it out, it could be one of two things:
1) The scaling of the procedural has somehow been gimped by the adding of the displacement mask texture. It looks like it's been reset to a 1x1x1 scale, although its placement node reads as 15x5x15.
2) Mental Ray's subdivision of the shader has been gimped by the adding of the displacement mask texture. It will provide similar (although scaling appears off) results if I try to bake the procedural texture out to a file and render it that way.
I'm wondering what to do, how to work around this. I am working in Windows, Maya 5.0 Unlimited, rendering in Mental Ray. The only solution that is really coming to mind is somehow using vertex colors as a substitute for the displacement mask (baking the B&W mask onto the vertices as opposed to applying a file texture), but not really sure how to incorporate that into a shading network.
Thanks for reading this far, and any help would be greatly appreciated.
I've recently been texturing a hill, using displacement maps to create extra details in the rock face. I'm using a procedural shader, and I've tweaked the scaling until I've ghot the right sort of striation in the rock. It looks great, all is well and dandy.
However, I want to be able to tell it where to displace and where not to displace. Basically, I don't want it to displace on flat surfaces, where there are supposed to be roads and houses. To this end, I've made a b&W TGA "displacement mask" that fits fine on the hill.
My basic thought was to multiply the displacement mask by the procedural, so that where the displacement mask is black (i.e. zero), the total displacement would amount to zero. But that isn't what's happened.
What's happened is that the procedural texture doesn't subdivide the same way it does when it is acting without the mask. In fact, it provides radically different results. I'll try and post some renders in a couple days (when I am back near an FTP server I have access to), but essentially, the unfettered procedural produces nice results, the fettered one makes a very CG-looking, unnatural result. You can actually see the pattern of the procedural. It looks awful.
Far as I can figure it out, it could be one of two things:
1) The scaling of the procedural has somehow been gimped by the adding of the displacement mask texture. It looks like it's been reset to a 1x1x1 scale, although its placement node reads as 15x5x15.
2) Mental Ray's subdivision of the shader has been gimped by the adding of the displacement mask texture. It will provide similar (although scaling appears off) results if I try to bake the procedural texture out to a file and render it that way.
I'm wondering what to do, how to work around this. I am working in Windows, Maya 5.0 Unlimited, rendering in Mental Ray. The only solution that is really coming to mind is somehow using vertex colors as a substitute for the displacement mask (baking the B&W mask onto the vertices as opposed to applying a file texture), but not really sure how to incorporate that into a shading network.
Thanks for reading this far, and any help would be greatly appreciated.