I wanted to use an alpha texture map to make a lighting fixture with a cut-out shade that casts appropriate shadows. To try this, I took a cube, texture mapped a spiral in alpha and put a light source inside the box. The box looks good, but no light is emitted from the box. If a spotlight is put in to the side, it casts a solid shadow.
I’ve attached an image. The box with the cutouts has a “lamp” light source inside. There’s another dull point source way to the left to provide ambient light, and a spotlight to the left to show the cube casting a solid hadow on the purple box.
I’ve read what previous similar discussions I could find, and this is what I’ve tried: For the boxes, I have “Full Osa”, “ZTransp”, “Traceable”, and “Shadbuf” turned on. For the lamp, I have “Ray Shadow” turned on. Any help would be appreciated.