View Full Version : Surface Thickness

12-07-2004, 09:45 AM

i have problem with surface thickness gradient map.

Here is object with surface thickness gradient map applied as diffuse. You can see an error, where poly is beveled. I have on double sided polygons and raytrace transparency, but still there is this strange transparency problem. I dont use transparency object. What I have to do to render this correctly???

12-08-2004, 05:35 AM
Anybody please, how use surface thickness in a right way????

12-08-2004, 06:26 AM
Attach the scene & object!

12-08-2004, 10:02 AM
I bet it got something to do with the ray re-entering you object. As soon as it passes the front side of a polygon for a second time, surface thickness is replaced by surface sickness and doesn't work properly any more. :hmm: But that's nothing I now for sure, but remember to have had similar problems with faking SSS.

12-08-2004, 10:21 AM
Dunno if this is the answer but turn on all reflection options, raytracing etc... maybe it's a shadow map problem...

Maybe changing the background would help make the error stand out more too...

12-08-2004, 01:18 PM
here is the files

problem is in areas, where are more than one polys in a view (sorry for my english, I hope i know what i mean). But how fix this??

Surface thickness work only for balls ???? :) I wanna apply it to head or something, but what about nose or ears ???

12-08-2004, 02:32 PM
There's no error. Surface thickness can be quite frustrating in this respect. Surface thickness is measured based on camera angle. From this angle, there is a larger distance where the "error" is. It's just shooting a ray through the surface and measuring the distance until the ray hits another surface.

Shaders like Coffee or Ska (only ones that come to mind) will produce a more accurate results because they measure "thickness" based on multiple angles (probably shooting multiple rays from each initial ray intersection.


12-08-2004, 02:47 PM
But it looks like a transparency. They should render only first thickness and dont show polys which are not visible!!!

12-08-2004, 03:24 PM
I copied your diffuse surface thickness gradient to color to better illustrate it.
I'm happy Newtek added Surface Thickness as an option but it's not as useful as I initially hoped it would be (quick SSS,etc).

(animated gif)

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