AnsweredAssumed Answered

Showstopper time - cannot render glass shadows

Question asked by Kevin Quigley on Jun 27, 2008
Latest reply on Jun 27, 2008 by 1-9C36HC
I've been running some tests today on the glazed canopies I do for a customer and have found a showstopper issue in that PhotoView doesn't render the ground shadow properly under glass. See the attached images.

In these images the glass panels used the gloss clear glass material. I also tried all the other glass and the clear plastic materials but they were all the same.

In buggy store final render the facing panel is glazed and you can see that the ground inside the enclosed section is not shadowed at all.

In buggy store final render 2 I removed the facing panel and you can see that the ground shadow in that section is very dark.

The issues are:

1. The glass materials are not realistic enough
2. The shadows BEHIND glass are too dark - they seem to treat the glass as an opaque object.
3. The ground shadows are not showing up behind glass (may be a reflection thing but I doubt it - look at the panels on the image and notice that the red vertical columns show up behind the glass OK, but the ground does not.

This is a complete show stopper for anybody rendering glass objects. But it also clearly demonstrates why we need to have more direct control over the materials and environment.

FYI Hypershot 1.0 had the same issue.

Other info. These rendered in 6 mins, which is a bit faster than Hypershot, but, the quality of the image is not too hot. There are artefact issues on the edges of the curved beams, so maybe the anti aliasing needs turning up a notch?

For this kind of work, currently, Hypershot gives a superior render.