Occlusion creates 'blotchy' shadows [SOLVED]

M0bil3D

I'm trying to create a scene that uses occlusion - specifically, I'm using the Lights_UberAndArea preset that comes with Amazing Skins for G2M. One of the lights in the preset, UberSphere_OcclusionContribution, when enabled, causes this to happen.

https://pasteboard.co/I6IRWGF.png

I'm assuming this has something to do with the fact that this article of clothing is both transparent and close to/touching the skin, combined with how the render engine (3Delight) handles the lighting. I've seen the same issue in other scenes that didn't use occlusion, and the solution in those cases was to disable 'Cast Shadows', on the tights, but this particular light seems to have a different method of creating shadows (if you look under the Shadow menu shown here, the Shadow Type is set to None) that ignores the Cast Shadows setting.

https://pasteboard.co/I6IYp1U.png

Is there any way to get around this issue?

Richard Haseltine

Please upload the images to the forum, assuming they obey the ToS - my security software is blocking access to the host you used.

However, from the description of the issue it could well be that the separation between the two layers of mesh is sometimes less than and sometimes greater than the Shadow Bias setting (which is also available for the occlusion light as I recall) causing the areas with a smaller separation to be unshadowed and the areas with a greater separation to be shadowed. Try lowering the bias setting for the shadow/occlusion generating lights and see if you can tame the effect that way

Sven Dullah

derekizatt said:

I'm trying to create a scene that uses occlusion - specifically, I'm using the Lights_UberAndArea preset that comes with Amazing Skins for G2M. One of the lights in the preset, UberSphere_OcclusionContribution, when enabled, causes this to happen.

https://pasteboard.co/I6IRWGF.png

I'm assuming this has something to do with the fact that this article of clothing is both transparent and close to/touching the skin, combined with how the render engine (3Delight) handles the lighting. I've seen the same issue in other scenes that didn't use occlusion, and the solution in those cases was to disable 'Cast Shadows', on the tights, but this particular light seems to have a different method of creating shadows (if you look under the Shadow menu shown here, the Shadow Type is set to None) that ignores the Cast Shadows setting.

https://pasteboard.co/I6IYp1U.png

Is there any way to get around this issue?

Yes, you should try what Richard suggest first. But the bias is already set rather low, I can see from your attached pic, so it may not work properly. You could also try applying the OmUberSurface to the clothing, then in the surface pane disable occlusion.

M0bil3D

Thanks for the responses. I'll work with setting the shadow bias to 0. It makes things a little darker, but doesn't seem to be causing any issues in this particular scene.