Quote - It does work in the sense that it happens. But the results are sloppy at low settings, and only "ok" at high settings. Remember, fast IDL means more errors. We've already seen that relying 100% on indirect illumination either means long render times or poor quality.

I say that because if you point a spotlight into a prop umbrella, it's pretty much the same as using a self-lit prop umbrella, in terms of illumination. You're not using the light directly anymore. On the other hand, it will be slower and require an extra bounce. If you were using 4, you'll need 5.

My demo here is that a hybrid approach stays away from the bad part of the performance of either. Using lights only, it requires that we use an array of many lights grouped in a cluster, which is slow. Using small self-lit props only, it requires that we use 20000 samples and very little caching, which is extremely slow. Using large self-lit props allows lower sampling and faster rendering, but won't fit into interiors.

This is a hybrid approach that pretty much solves all the problems at once - good rendering quality, convincing lighting, easy placement options, and fast renders.

And it's f'ing FREE, not $9.99.

You're absolutely right.  I tried turning the light into the umbrella and it pretty much just looked like it was lit only by the self lit prop.  

But I want to make sure I have the thinking right behind your approach.  Your approach makes it possible to use spotlights with low intensity and the light prop behind it gives extra illumination and softens the shadows.  Isn't that just about right?

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