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View Full Version : Getting a different surface to appear inside of a Fast Simple SSS object.


mocaw
01-17-2006, 03:51 AM
I have a issue that is perplexing me with the included fast simple SSS shader. I have a fleshy object that has a horn in it that needs to grow out of the skin. I know I can group the two objects so that the light map sees each, but how do I get it so that when the object comes out it's the horn surface and not the skin surface?

I've tried using a distance based gradient on the SSS shaders diffuse, but that only gets the horns center. I've tried Ambient Occ shaders hooked up to different ports too, but that only works on the visable surface of an object.

Is this something that I should use a modeling operator such as slice polygons with two horns (one for each surface) instead of using the render tree solution? Do it in post?

I'm just wanting to know if there is a render tree solution before I using a modeling op or a post method on this.

Thanks,
Gideon

bravmm
01-17-2006, 02:37 PM
what about creating passes? one for the skin and horn inside, one for the horn growing out of the skin. Some partitions with overrides and materials will do the trick I guess. The horn has to be a duplicate with different material offcourse ;)

rob

mocaw
01-17-2006, 03:50 PM
Yeah, I figure I'll just do it in post or with the slice op and to versions of the object. I was just wanting to know if anyone had managed to get a different material to show up inside of a fast simple SSS object.

CiaranM
01-17-2006, 04:52 PM
Hello,
you should use the fastSSS split shader that can be found somewhere on this board or on xsibase.com. With this you can then use a weight map to control where the SSS effect will and will not be present.

mocaw
01-17-2006, 07:46 PM
Hello,
you should use the fastSSS split shader that can be found somewhere on this board or on xsibase.com. With this you can then use a weight map to control where the SSS effect will and will not be present.

So how would I use this with an animated object? Sorry...I'm just not sure how I'd get the proper effect with a weight map on a subdivided mesh that isn't that dense...

mocaw
01-20-2006, 07:17 PM
Found a cheap quick solution...but not always the most practical!

You hide your SSS object (in this case a horn) inside of the non SSS object. Simply scale the object by the normals so that it is slightly smaller than the non SSS object. The light map will not see the non SSS grouped object, and the camera will only see the non SSS object! Works great...but adds geometry and complexity to a scene...but it does work.

If it needs to be animated you can just parent the inner object to the outer one...

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