Author Topic: Thin glass - no light passing through at lancing angles.  (Read 274 times)

2023-12-01, 10:30:36

busseynova

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I have a glazed partition with a thin glass material , the mesh is arrayed with railclone and the segment itself is just a single face - no thickness.

At glancing angles (less than about 30 degrees) there appears to be no light passing through the glass.

Is the single face approach correct when using thin glass material? Any ideas what's causing this problem?


2023-12-01, 11:00:29
Reply #1

burnin

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Have you tried to edit geo and shading (multi/single, tris/quads, smooth/sharp/custom nrml/ edge weights)?

2023-12-03, 22:44:19
Reply #2

busseynova

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yes it was the geo that was the issue, specifically I had edited the glass to that it was a single face rather than a water-tight, shelled plane. in the problematic areas the direction of the base spline on the railclone object meant we were seeing the back face of the glass. That's fine, I usually would shell glass anyway but in this case I have a bump making the glass ridged and didn't want to overcomplicate the look of this by having two ridged surfaces. In the end I added a front/back map so the bump only rendered on the face closest to the camera.

It does make me wonder though - if we use a thin glass, with shelled geometry, don't we effectively end up doubling up reflection? - i.e it's like having a double glazed window rather than a single pane of glass. Obviously this might be desirable in some cases, but in this case I'm trying to create a single glazed partition (or at least simplify the rendering/look to the greatest degree possible.

2023-12-04, 08:35:08
Reply #3

Aram Avetisyan

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Hi,

The original issue is most likely normals/smoothing problem. Sometimes chamfer (and even shell) modifier can cause this. Always check if there is any smoothing issue right after applying these modifiers.

For the second question, about double glazing - yes. Thin mode/Thin shell disables the refraction for the material (light bending), it basically becomes air-like refraction-wise, but keeps the reflective properties.

Hope this helps.
Aram Avetisyan | chaos-corona.com
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