Hi

I want to use a dome light in combination with several portal lights for high contrast areas.
When I plug in the portal light, Karma stops sampling the dome light environment map and only samples the Portal Lights.
I tried the Portal Light LOP and also classic geo by enabling Is Portal in the Render Geometry Settings.
It sounds like the Portal MIS Bias is exactly what I need but it doesn't make any difference when changing it.
I'm in Houdini 21.0.440.
Does anyone have an idea how to set this up?

Thanks!

Hi,

Yes for high contrast area setting Portal MIS to -1 (sampling environment map) may be more beneficial.
However the option seems to be broken when using Portal Light HDA (attached hip file).
I will investigate it further.

It would be great if you could log a bug and attach a sample model too. Thanks!

It actually is working as expected, sorry. I was playing with MIS Bias instead of Portal MIS Bias.
Please try the hip file I shared on the previous post and change the option on the dome light Karma tab to see the effect.

There are two node branches in the hip file that demonstrate the old (via Render Geometry Settings) and new style (Portal Light HDA)
of setting up Portals.

Please report a bug if this doesn't help. Thanks.