If you are playing with materials and trying to do transparency with specular maps, you may have run into problems. The problem came up on Plurk and Geenz, the one coding the project, replied in the comments on Inara Pey’s site.
Laverne Unit – April 10, 2013 at 16:56
After some testing, it seems that you can get specularity with diffuse maps with alpha masking, but not with diffuse maps with alpha blending. I don’t know what the intended behavior is, but that’s how it works at present.
Geenz Spad – April 10, 2013 at 17:36
The intended behavior (eventually) is that alpha blended objects will be able to support both normal mapping and specular mapping. Currently this is a work in progress, and due to its current state, it hasn’t been added to the viewer just yet.
UPDATE: 4/10 – [16:02] Open Source Meeting – Geenz Spad:
So yeah, be on the lookout for materials on semi-transparent objects, it’s coming, I’ve even been working on it for the past week; don’t mope about it not being there too much.