Now I introduce a shader called "Tricky Glass". Click here to read about it

This is a dual shader that asks the renderer "Why are you here?" If the renderer is asking "To see what you look like" the shader says "Glass". If the renderer is asking "To see if you block (shadow) the path to this light source I'm looking at" the shader says "Transparent". (Or various subtle combinations of other things, but that's the basic idea.)

The result is a beautiful and accurate pattern of light and shadow from a point light in SuperFly, that converges in minutes, not days. Notice how the light is modulated by the glass shade. Some people think you need IES lighting simulators for this. You do not. Point lights and tricky glass can work very well to do realistic light patterns. The tricky glass can even be invisible, and just modulate the light pattern from a point light.

Learn your tools. If you don't know how to get the results that others are asking for and you think you have advice based on what what you imagine to be the truth, consider just saying nothing.

When a scene is modeling a tiny light source, such as a single bulb in a big room, the answer is point light, not area light.

Take particular note of the caustics on the table. To see those, the renderer had to pass the light through SIX Tricky glass surfaces (4 for the vase, 1 for the lamp shade, 1 for the light bulb -- the point light was inside the bulb.)

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)