Laser and Volume Scatter

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Jan
Posts: 37
Joined: Sun Jan 10, 2021 2:37 pm

Laser and Volume Scatter

Post by Jan »

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
laser_scatter scale 0.1.jpg
Scattering Scale 1
laser_scatter scale 1.jpg


my setup
Snap5_laser.jpg
Attachments
laser beam thru glass.blend
(1.13 MiB) Downloaded 125 times
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DionXein
Posts: 81
Joined: Mon Jun 01, 2020 10:22 am

Re: Laser and Volume Scatter

Post by DionXein »

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
Attachments
Pr_1.jpg
Pr_2.jpg
Last edited by DionXein on Thu Apr 01, 2021 9:49 am, edited 1 time in total.
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Dade
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Re: Laser and Volume Scatter

Post by Dade »

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:

laser.jpg
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Jan
Posts: 37
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Re: Laser and Volume Scatter

Post by Jan »

Thank you guys. I got it working but is there a way to simulate also refraction and partial internal reflection?
refraction.jpg
With Null Object refraction also doesn't seem to work.
Snap5_laser_null obj.jpg
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Dade
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Re: Laser and Volume Scatter

Post by Dade »

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.
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Jan
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Re: Laser and Volume Scatter

Post by Jan »

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?
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Dade
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Re: Laser and Volume Scatter

Post by Dade »

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.
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Jan
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Re: Laser and Volume Scatter

Post by Jan »

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
Snap11_laser thru glass.jpg
Spot Beam
Snap11_spot thru glass.jpg
Attachments
spot beam thru glass.blend
(1.13 MiB) Downloaded 124 times
Jan
Posts: 37
Joined: Sun Jan 10, 2021 2:37 pm

Re: Laser and Volume Scatter

Post by Jan »

Thanks again! Got it fully working now. It needed another External Volume Shader Node for the Plane Object beneath the Glass Cube Object. 8-)
laser thru  glass with refraction and reflection.jpg
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