Alex Q

Maybe the Light linker just works on the direct illumination. It is quite annoying.

Hello everyone,
I need some help because i cannot figure this out myself.
I have two volumes layered like cloud strata. It seems that Houdini’s Light Linker doesn’t fully block light as expected. When I try to restrict a light to only affect the lower cloud layer, global illumination still appears to bounce off the upper volume. For example, even with a single downward-facing light meant only for the lower clouds, the upper volume still receives some indirect light. As soon as I set the Volume Limit to a value like 32 in Karma, the upper cloud starts picking up bounced light from the lower one, which I’m trying to avoid. I had assumed the Light Linker would isolate the lighting completely, but that doesn’t seem to be the case. This is becoming quite problematic for the look development of the project, especially since our scenes are very large.

Thank you
Alex.

Hi everyone

I have some issue to get my vel works properly, if someone may help it would be awesome.

1) Just a simple ripple wit wrangle converted to SDF

2) I 've Built a volume using VDB from poly, then Added cloud noise etc... Then build a vel with a VDB analysis with a custom value vel. Then I've combined my velocity fields into a vector3 field using the scalar to vector sop

3)Then I am trying Velocity Field in a Volume VOP (problem here i guess)

4. I am trying to Push the Density with VDB Advect I connected my original density VDB to the first input of the VDB Advect node, then plugged the velocity VDB coming from the Volume VOP into the second input. I set the advection method to MacCormack (you can also use Semi-Lagrangian) to push the density using the velocity field. My problem is here or inside the Volume vop. I get an error on the advect: (Unrecognized velocity grid type)

{{{The reason I am trying to use this way it is because if an another way i subtract my ripple density to my cloud density with a volume wrangle it does not look realistic, Then maybe better to trying to push the voxel directly, The final result could be a wavy cloud on large scale cloud.}}}

Thank you

{{IN the video It is the volume wrangle not the one I am trying to acchieve and i am not satisfy with that way.}}