View Full Version : Light Reflections

Chris Jones
04-02-2014, 07:51 AM
Area lights decrease in intensity when they're scaled up. That's not particularly convenient, but I've learned to live with it. Luminous objects increase in intensity when they're scaled up (if viewed in the reflection of an object with reflection blurring turned on). Also not convenient.

What's particularly inconvenient though is when you're trying to use an area light with a luminous plane serving as the light's reflection (in place of a specular highlight), and you've got a disparity between the light's intensity and the intensity of its reflection. So what I'd like to do is sync the two via some automation.

I thought I was getting somewhere with the following node setup and an exponential gradient in the Gradient (2) node (I don't know how to accurately generate one, so I eyeballed it), but for some reason the luminosity remains constant until the light has been scaled past a certain threshold. In fact it doesn't seem to matter what kind of gradient I come up with, I just can't get the object's luminosity to increase when I shrink the light, even with settings of 1,000,000,000%...


Is this worth persisting with, or is there already a tool that couples lights and their reflections in this way?



04-02-2014, 08:37 AM
The intensity of the area light is constant over the entire area of the light... the intensity of the polygon lum is constant at each spot on the poly... this is where the discrepancy comes in. As such you need to get the square of the size for the light (or more ideally its actual area) and use this value to drive the plane luminosity value...

Chris Jones
04-02-2014, 07:40 PM
Well, even though I had the right nodes in there, I'd never have thought to plug them together like that.

Thank you good sir!