(open)[HOU-3508]Emit light from Points using shading as color

[jbvfx]

Hi,

Is it possible to emit lights from points and drive the color of the each light with a shading network on the points?
It would need to be direct illumination and not GI/Self Illumination.

Best,
Jacob

[Dubbie99]

You could compute the color as Cd, then just use the instancer to replace the points with lights.

[jbvfx]

But I want to drive it with a shading network using multiple ramps and user attributes

[Dubbie99]

I guess you can do all that stuff in a wrangle easily enough.

sorry I don’t know of another way with shaders

[chakarov]

Hi jbvfx , V-Ray LightMtl with Direct Illumination ON, does not support points, you should copy spheres over points. But looks like there is an issue wen using attribute as color multiplier for LightMtl, I've logged it in our system. For now, only solution I can give you is to do your @Cd and @intensity manipulations via VEX/VOP and use instancing of LightSphere.

[david.anastacio]

But I want to drive it with a shading network using multiple ramps and user attributes

Hey

You could try to do that but in SOPs, using the an instance node with points and the "Cd" attribute like Dubbie99 suggested (just make sure to force the attributes with the object properties) and also the "intensity" attribute, just manipulate the attributes as you would in the shading network with wrangles, remaps, etc.
But I have to say that a similar request came up already in talks we had with Gosho.Genchev.

You can do this with mesh lights (just make sure to force those attributes with object properties), and you could also try to use a light material and toggle the "Direct Illumination" option with point rendering, but honestly none of these will be as fast and optimised as the sphere lights instanced.

Best,
David.