As a small challenge to learn shading I'm trying to do a simple earth planet in Houdini.
It fits my modelling skill…
Anyway, I have 2 maps, a day and a night map, I was just wondering if it was possible in Houdini to group some faces or points by “hit by a specific light” or not, and thus remplace shading by group (if it is a good idea or the good way to do it).
Also is it possible to do a bit of gradient transition between the 2 textures ?
This would be nice to know how to do this effect in Houdini. I know C4D has some xpresso nodes for handling when a light is illuminating a surface.
Here is a start. Basically I am trying to use a lighting model at the SHOP level to control the bias on a mix colors node. I have taken the X vector out of the direct lighting shadow socket to control the mix. This demonstrates that some kind of control can be achieved but it is far from complete.
I don't really know what math needs to happen to turn the direct lighting model in to a controller, preferably based off the spotlight falloff.