Light Bias Still Useful?

[Joelaff]

Are the light bias settings still useful, other than constantly having to lower them when you get random shadows issues?

I have yet to see issues with this value set too LOW. Can that happen? What happens if it is too low? Certainly made sense with shadow mapped lights, but what exactly is it doing with a regular VRayLight (plane) ?

Thanks.

[^Lele^]

The shadow bias works analogously as it always has.
If a scene is big enough, and the bias is low enough, you may get coplanarity issues (acne, fighting, streaking, moire'. as one pleases.).
There is sadly no automatic biasing technique in literature that I know of (certainly none that has been adopted by anyone else.), so it has to stay.

[Joelaff]

I guess I will just have to try harder to break it. On a few scenes I tried setting it to 0 and it had no ill effects. It is dependent upon the extents of the scene I guess, like Z fighting issues.

What is the default value based on? Unit settings? Thanks.

[Buck]

depending on your scene scale, sometimes it's useful to adjust it. I work with alot of real scale small objects, with closeups on fine detail I'll actually lower the shadow bias from .02 to .001 and get better defined shadows in small detailed areas.

[Joelaff]

Yes, this is what I frequently have to do for table top or macro setups. But it has been a while since I have seen any artifacts from lowering it too much. So I was wondering if it was still a thing in VRay 6. But I guess so.

[kosso_olli]

Same here, I have never seen any artifacts from lowering the bias too much. But we rarely work with huge scenes, so that might be different for other people.

[vlado]

My goal is to eventually remove these parameters and have V-Ray handle everything automatically, hopefully I will be able to get to it soon. The implementation has been sitting on my mind for a long time, maybe it's finally time to try it out.

Best regards,
Vlado

[Joelaff]

Would be interesting if you have a solution for it. I do prefer more user controls over less user controls.

This is one setting I do find myself having to lower from the default quite frequently, and never having to raise.

[Pixelcon]

just discovered this! Praise the lord
https://www.youtube.com/watch?v=X-_UCUlmCP0

[Vizioen]

just discovered this! Praise the lord
https://www.youtube.com/watch?v=X-_UCUlmCP0

Yeah I'm not willing to go to 2024 with the color picker problem, do you have issues with that?

[Pixelcon]

Yeah I'm not willing to go to 2024 with the color picker problem, do you have issues with that?

I use the corona improved picker which works. As for the standard max one, I'm really not sure.
Seems like a slatemate: https://forums.autodesk.com/t5/3ds-m...ht/true/page/5

[M.Max]

As a workaround( for Max 2021 to 2023) you can set the default state for Any parameter using this script :
https://cganimator.com/3dsmax-2021-1...d-the-manager/