LuxCoreRender Forums

Hi, What settings to use to see a laser beam clearly and sharply through a volume?

I already tried different Scattering Scale Values between 0.1 to 1 but it ends up either too faint to see or too blurred out.

Scattering Scale 0.1 Scattering Scale 1

my setup

1) Why did u use Glass Material? If u are looking for only volume affects laser - just put Null (Transparent) instead of Glass.
2) Homogen absorb colour shouldn't being black(at least completely black)
3) Laser source should be really small - now u have size of 30cm. Put some lower values (0.002 for example)
4) Increase performance for laser in lamp settings tab.
5) If using BiDir pathtracing - set Sampler from Sobol to Metropolis

This:

1) set cube material to "null" (not glass);
2) multiply laser light source power by 10;
3) set volume absorption to 0;
4) divide volume scattering by 10

and the result is:

Thank you guys. I got it working but is there a way to simulate also refraction and partial internal reflection?
With Null Object refraction also doesn't seem to work.

Jan wrote: ↑Thu Apr 01, 2021 1:38 pm With Null Object refraction also doesn't seem to work.

Refraction is a feature only of glass material (i.e. volume IOR is used only when going trough a glass surface). NULL is just a passthrough material.

Dade wrote: ↑Thu Apr 01, 2021 2:33 pm

Jan wrote: ↑Thu Apr 01, 2021 1:38 pm With Null Object refraction also doesn't seem to work.

Refraction is a feature only of glass material (i.e. volume IOR is used only when going trough a glass surface). NULL is just a passthrough material.

What Material to use if the object is liquid?

Also why is Volume Scattering behaving erratically with Glass Materials which is per se transparent?

Jan wrote: ↑Thu Apr 01, 2021 2:54 pm What Material to use if the object is liquid?

Glass.

Jan wrote: ↑Thu Apr 01, 2021 2:54 pm Also why is Volume Scattering behaving erratically with Glass Materials which is per se transparent?

It doesn't It works like a glass with refraction and (internal) reflection. Null material should be like a glass with IOR 1.0, 0.0 reflection and 1.0 transmission.

P.S. there is also some other factor related to what a BiDir or Path can or can not render but that should be your problem.

Dade wrote: ↑Thu Apr 01, 2021 9:21 pm
P.S. there is also some other factor related to what a BiDir or Path can or can not render but that should be your problem.

Thanks Dade. I got the laser beam refraction and reflection through glass almost working now by hiding the Glass Object from Camera. There's still something strange however and I cannot get the beam to come out visible from the glass cube beneath. That means no more light scattering after coming out and returns only after hitting and bouncing back on a Matte Plane Object???

Laser Beam Spot Beam

Thanks again! Got it fully working now. It needed another External Volume Shader Node for the Plane Object beneath the Glass Cube Object.