LuxCoreRender Forums

Blender 2.79b
LuxCore 2.1 alpha0
CPU Path + Metropolis (also BiDir + Metropolis and Path/BiDir + Sobol)

Glossy Translucent Material with interior homogeneous volume
I can't see any difference, though every ball have different absorption depth
From left to right: 0.01 mm, 0.1 mm, 1 mm, 1 cm, 1 m, 10 m, 100 m

The transmission color of the glossy translucent mat is black, so the volume does not make any difference because no light is transmitted.

B.Y.O.B. wrote: ↑Thu May 17, 2018 3:03 pm The transmission color of the glossy translucent mat is black, so the volume does not make any difference because no light is transmitted.

Do you have an example scene, which shows the difference in absorption depth? I still cannot figure out how absorption depth affects the material.
This scene has transmission color 7F7F7F at all balls.

Yes, looks like it's something wrong in Blender.
PS.
It works fine in Material Preview, but not in Render Preview nor in Final render.

wasd wrote: ↑Thu May 17, 2018 3:52 pm Do you have an example scene, which shows the difference in absorption depth? I still cannot figure out how absorption depth affects the material.

The absorption depth is the distance after which a white light ray (1, 1, 1) has the color that is specified as absorption color.
You can see the effect best with the null material.

B.Y.O.B. wrote: ↑Thu May 17, 2018 5:40 pm

wasd wrote: ↑Thu May 17, 2018 3:52 pm Do you have an example scene, which shows the difference in absorption depth? I still cannot figure out how absorption depth affects the material.

The absorption depth is the distance after which a white light ray (1, 1, 1) has the color that is specified as absorption color.
You can see the effect best with the null material.

What about an example?

OK. I get it. Volumes just don't really work with anything but Null material.

Volumes are independent from materials.
The material describes the surface, the volume describes everything inside or outside of the surface.

You might see something else than you expect because the material reflects too much light and transmits too little?

From left to right:
- Null
- Matte Translucent
- Glossy Translucent
- Glass
- Rough Glass

Hope this helps.

B.Y.O.B. wrote: ↑Thu May 17, 2018 7:56 pm You might see something else than you expect because the material reflects too much light and transmits too little?

Maybe.

wasd wrote: ↑Thu May 17, 2018 8:46 pm Maybe.

You are confusing object transparency (or opacity if you prefer) with object surface+volume. Transparency makes all object (surface+volume) transparent, like with alpha channel. In your case must be set to 0, it is not what you are looking for.

The object material describes the surface (i.e. the "skin") of an object while volume describes the interior.