View Full Version : Light Intensity Gradient

Gui Lo
03-07-2003, 08:18 PM
Hi, I was doing a scene depicting a flash light moving and illuminating a night scene.

I wanted an effect where the image is mainly monochrome until the area is lit and the it shows up in colour.

I managed to fake it with light incidents but it would be nice to have a light intensity gradient so that the colour, spec, transparency or bump can be altered by the intensity of the light it receives. Also this would work with several lights.

What do you think?

Gui Lo

03-08-2003, 05:39 AM
Yeah, I agree. Having gradients for overall light intensity, shadow coloring etc. could also greatly benefit toon shading and analytic (pseudo-thermal) renders with GI for instance. Th limitation of one light only for light incidence is a bit annoying and even then it ignores any shadowed areas.

However, from what you described the effect could have ben easily achieved using compositing. I assume you do not have any such tool so I would vote for getting one if you are doing such things more often. Also comping can save your butt in a lot of other situations ;).


Gui Lo
03-08-2003, 12:10 PM
Thanks for the reply Mylenium.
I have photoshop and Aura to do comp work. The light does not produce a perfect circular shape and is often broken so comping was dismissed and I went with faking the effect and altering a few camera angles.

I'm glad you mentioned the shadows, since I forgot and it is one of the main reasons why Light Incidents does not work well.

Another use would be colour bloom where colours look over saturated when the pass from shadow into daylight.

Gui Lo

Robert Zeltsch
03-09-2003, 06:33 AM
Not only for toon shading or so. Think of volumetric effects and the light passing through!!

Cool idea! :)