So, I'd like to simulate a light bulb in Fusion. Basically, to have a sphere that's mostly transparent with a light source in the middle; and the intensity of the light source increases, the globe glows brighter. I tried placing a point source light in the middle of a sphere, and turned down the alpha and opacity of the sphere, but that doesn't work -- no light is seen.
Can someone give me a few hints are to how to do this?
You can't actually see 3D lights as you would lights in the real world.
A simple way of simulating a light source would be to add a 3D sphere, piped into a 3D renderer and then piped into a blur so soften the edges. Then simply Merge this with your Lightbulb either with Screen or Additive.
You will need to make sure that the 3D sphere and your "glow" are sharing the same 3D camera of course.