Author Topic: Light beam not rendered correctly with fog  (Read 5256 times)

2021-06-02, 03:30:33

Basshunter

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What could be the reason for this problem?

« Last Edit: 2021-06-02, 17:52:40 by Basshunter »

2021-06-02, 16:01:41
Reply #1

Nejc Kilar

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Howdy!

Could you please try disabling the "adaptive light solver" in the render settings -> performance compartment and then try to re-render? Kind of looks like that could maybe be the culprit, would really appreciate it if you could try it out and report back.

Thanks!
Nejc Kilar | chaos-corona.com
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2021-06-02, 17:34:39
Reply #2

Basshunter

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Hi Nejc!

I tried turning "Adaptive Light Solver" off but the problem persists.

« Last Edit: 2021-06-02, 18:04:48 by Basshunter »

2021-06-02, 18:34:36
Reply #3

maru

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It would be nice to disable the AI denoiser - otherwise it is hard to see the base image quality, e.g. if the noise is uniform or if there are some "holes" in it.
You can try increasing the Light Samples Multiplier in Render Setup > Performance from the default 2 to something like 4-8. It will give you better quality of direct lighting (=what we see inside the fog).
Marcin Miodek | chaos-corona.com
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2021-06-02, 21:27:13
Reply #4

Basshunter

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Hi Maru.

I disabled denoiser and tried increasing "Light Samples Multiplier" but still can't get a clean image. Even after 30 mins the whole image has artifacts and the light beam is not renderer as expected. If at some point you feel it'd would be a good idea to take a look a the scene by yourself, just let me know and I'll share it.

2021-06-02, 21:57:46
Reply #5

mferster

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Have you tried a render test without the light's housing around it?

2021-06-02, 23:05:18
Reply #6

Basshunter

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Have you tried a render test without the light's housing around it?

I have. But nothing improves apparently.

2021-06-03, 10:59:55
Reply #7

burnin

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See if this helps...
Set Volume to "Single Bounce only" & make it's mapping "Step size" larger

PS
I found it somehow hard for Corona to clear noise (finding light in Volume) near its source

2021-06-03, 14:13:14
Reply #8

PROH

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Hi. Just made a quick test with the sttings you provided as a starting point. I found this working:

Render settings:
Adapive Light Solver - OFF
Light Samples Multiplier - 8

Volume material settings:
Absorbtion Color - 128,128,128 (or lower)
Single bounce only - ON

The absorbtion color seems to be the single most important to reduce the noise.

Hope it helps

2021-06-03, 15:40:32
Reply #9

Basshunter

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Thank you burnin and PROH for your suggestions. I tried using your settings but I'm afraid "Single Bounce Only" is not an option for me in this case. It reduces the scattering of light across the scene significantly, making everything too dark. My client and I need the lights to behave as close to reality as possible for this project.

On the other hand, I didn't see a great improvement in terms of noise reduction with any of the suggested settings. The renderer keeps having problems specially on the areas of the beam closer to the source. I guess these kind of effects like fog and steam are just difficult for renderers.

I'm a little worried at this point not knowing how I'll solve this issue. There're still another 41 moving heads to be added to the scene :c

2021-06-03, 15:46:55
Reply #10

TomG

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Don't forget you can always send the scene to us via private uploader, see link in my signature, and we can take a look at your specific scene directly.

(BTW single bounce only usually makes the rays more prominent, and perhaps the loss of light across the scene as a whole could be compensated for by adding lighting that illumates the whole scene, just as a thought).
Tom Grimes | chaos-corona.com
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2021-06-03, 16:12:13
Reply #11

PROH

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Hi. Hmmm.. before writing my previous post I actually made a direct comparison between your settings and my suggested settings, and found a noticeable improvement. So it seems theres something else thrown into the equation.

Besides that, I have done something like this before, using the standard Max light with "volume light" render effect for the beams only. That worked out quit well, with less noise and faster render times than Corona Volume Mtl. Maybe that's something to try out?

Regards

2021-06-03, 16:43:56
Reply #12

Basshunter

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Thank you, Tom, for the tips. I'll prepare the scene and send it to the team. By the way, is there any benefit, at least in my case, from using a Volumetric Material on the Global Volume Material slot instead of a box or vise versa?

Quote
Hi. Hmmm.. before writing my previous post I actually made a direct comparison between your settings and my suggested settings, and found a noticeable improvement. So it seems theres something else thrown into the equation.
Maybe I missed something. There's a couple of mesh lights on the ceiling which I didn't mention because they're being rendered just fine. I'll take a closer look to the Max lights and see if I can get something from it.

2021-07-24, 06:38:12
Reply #13

Basshunter

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Just revisiting my own post. I couldn't prepare and upload the scene before. I just did. Here's what I'm getting using Corona 7 and 3ds Max 2022. I really hope you guys can help me with this when you have some time.

2021-07-25, 18:46:40
Reply #14

TomG

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Have you tried disabling Adaptivity?
Tom Grimes | chaos-corona.com
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