include/exclude lights from environment fog

[ronald_a]

is there a way to include/exclude lights from environment fog?

[Gosho.Genchev]

Hello,

light linking and volumes are not working correctly in the stable/nightly builds since Aug 14th - the core dev team has been working on issues there. If going back to the official builds is not an option, I'm hoping the change can be reverted for tomorrow's builds, I've pinged the devs and will message here once I know if a quick fix is possible.

I've attached a hip file showing how you can go about doing this here: https://drive.google.com/file/d/17VP...ew?usp=sharing

[ronald_a]

So do I understand correctly that your demo is not supposed to work with yesterday's stable. Also, this solution only seems to work if I use a gizmo but not environment fog (as in rop environment), correct? Because this is actually what I am after.

[Gosho.Genchev]

Yes to both. The demo won't work with the latest builds, we'll have this resolved ASAP.
The EnvFog implementation in Houdini is the same as Maya's - light linking is only possible with a geometry gizmo. You can wrap your entire scene in a piece of geometry - you won't take a performance hit from this.

[ronald_a]

I'm afraid I have to disagree. In maya it used to work to put lights into the envfog set and set the envfog mode to "override". This is currently just working with gpu because it is also broken there for some time now with cpu. But in houdini there is no way to tell the environment fog which lights to use and which not. Also, using a gizmo, if I place my camera inside of the geo, i will not see the fog.

So asides the core problems with volumes, i believe we are missing the functionality to do the linking.

[Gosho.Genchev]

My mistake, turns out that you are correct. I've logged a request for supporting this in Houdini, too.

Also, using a gizmo, if I place my camera inside of the geo, i will not see the fog.

Seems that there are two ways to limit the fog to the bounds of a certain piece of geo, and I was aware of only one. We'll add the other workflow as well.

As a side note, you could also parent a sphere under your render camera and reverse the vertex winding direction to flip the surface. I've attached an example here:
https://drive.google.com/file/d/1z_A...ew?usp=sharing


The devs are currently looking at the light linking issue.

Cheers!

[ronald_a]

Thanks Gosho