Hello everyone !

I use a lot blender to render my project, but since i'm using houdini more and more, i try the "solaris" workflow

Really nice for lookdev, but I have a problem. I make a lot of product with glass (bottle, perfum etc) render, and i can't find a solution to have a volume absorption in my glass with material x...

Any ideas ?

(by the way, the fact that when i activate the transmission of my material, the object disappears in my viewport is really annoying)

Unfortunately it's not a feature of Karma yet. Hopefully we get absorption, dispersion, and volumetric scattering for refractive materials in Houdini 20.

I have tried Transmission + sss which look similar to Transmission scatter to some extent

ysysimon
I have tried Transmission + sss which look similar to Transmission scatter to some extent

ysysimon
I have tried Transmission + sss which look similar to Transmission scatter to some extent

Interesting ! Do you have an exemple ?

Siavash Tehrani
Unfortunately it's not a feature of Karma yet. Hopefully we get absorption, dispersion, and volumetric scattering for refractive materials in Houdini 20.

Yes I Hope so, it’s a really important feature for a render engine…

philippepetitpas

ysysimon
I have tried Transmission + sss which look similar to Transmission scatter to some extent

ysysimon
I have tried Transmission + sss which look similar to Transmission scatter to some extent

Interesting ! Do you have an exemple ?

The result is not good, it can't achieve the normal Transmission scatter effect at all....(At least in karma)

Theoretically, the difference between Transmission scatter and Subsurface Sactter is that the light of Transmission scatter obeys the law of refraction when it first enters the surface. After entering the surface, it performs random hemisphere scattering like the subsurface.

This is just the theory I understand, I'm not sure if it's correct. hopefully sidefx will implement it for us so we don't have to deal with these theories

I really hope the developers add this through a new production build as soon as it’s ready.

I too have products with a lot of glass and water involved. It’s super important and I don’t want to wait until H20! :-)

So we are using 20.5 now, but still no sign of this? I really hope that this is on the roadmap for houdini 21.

There was some documentation issues where Transmission Roughness was still marked as not supported (fixed in tomorrow's cut), but everything except Transmission Scatter and Transmission Scatter Anisotropy are supported by Karma in Houdini 20.5.

this is the first h22 production build. Am I understanding this correctly that matX supports it but Karma doesn't?
Would this feature be on the roadmap within the v22 cycle?

janjansen
Am I understanding this correctly that matX supports it but Karma doesn't?

Correct, for transmission scatter in Karma you have to pair it with a copy of the geo with Unitorm Volume shader

However Absorption (the main topic of this thread) has been supported for a while

tamte

janjansen
Am I understanding this correctly that matX supports it but Karma doesn't?

Correct, for transmission scatter in Karma you have to pair it with a copy of the geo with Unitorm Volume shader

However Absorption (the main topic of this thread) has been supported for a while

cool, thank you for pointing to the workaround