Light data to generate geometry

[Josami]

Hello! I've been trying to get light data in some attribute or texture in order to use the shadows to generate geometry. Until now, the best approach has been baking the light as a texture and loading it using Attribute from Map. However, the baked texture works only if the character is static.

What would be the best approach to cache or cast lighting data in order to procedurally generate geometry? A shader, maybe?

 

Thank you in advance.

[konstantin magnus]

If you need light maps right on your geometry you could shot rays from the surfaces towards the sun. When objects are in the way you will get a shadow.

light_sim.hipnc

[Josami]

Thank you very much for your answer konstantin! It was really helpful. I’m thinking of using that shadow as a vector source to modify particles emitted from the character’s body.

However, the shadows I'm trying to use are the ones cast over the character's body — didn't explain myself. Based on your sample file I came across the idea of using an external geometry point as a fake light object, using its position to calculate the dot product. Just have to set a normal in the same direction the spotlight is pointing, and reference its position. It's a pretty basic and common setup, but maybe someone finds it useful.

 

 

 

FAKE_LIGHT.hiplc