shallow surface fog problem

V-Ray for 3ds Max V-Ray for 3ds Max :: Issues
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1

Hi
We are working on an aerial shot of an island and I was planning to use refractive material with fog for the sea…
I have a single mesh for the island and seabed, and a single plane for the sea..
The problem is that polysurfaces where the sea intersect seem to be not detected by fog parameter hence they cause the sea material to look dark.
image should be self explanatory, I have tried zeroing the refraction and transparency cutoff values but that didnt help.

Cheers

fogproblem.jpg
fogproblem.jpg640×480 59.4 KB

fogproblem2.jpg
fogproblem2.jpg640×480 34.5 KB

2

Hi,

I made a quick test with a similar setup and was not able to replicate your result.

Can you share some more details or simple scene file?

Capture.JPG
Capture.JPG1382×887 158 KB

3

Hi
I hope attached helps.

Looking forward for the news.
Thanks
maa-to-chaosgroup.zip (1.95 MB)

4

Hi,

Thank you for the file.
The darker boarder comes from the V-Ray Sun shadows, so please try to reduce the “Shadow bias” option. Values below 0.002 will give you better results I think.

5

Tashko could you please briefly explain Shadow Bias and how, if at all, it relates to scene scale? I’ve always gone with the equivalent of 2mm for any scene, so if I’m in metres then I use 0.002, if i’m in mm then I use 2. Is this correct?

6

Hi Alex,

Yes, this is the correct workflow for now when you are using V-Ray Sun. This case was considered before and we decided to make some changes on that regard, but unfortunately can’t give any time frame about it.

Here is one discussion about the same issue.

7

Thanks Tashko - good to know on both counts.

8

Thanks for the reply Tashko, for this project we have done the corrections in photoshop but your feedback is going to help for the further renders..