Spot vs Directional Lights sampling

[frodopytlicek]

Hi there is a bug how V-Ray sample standard lights. Please check this out. No special setup needed, just use defaults.

Spot on left directional on right.

[frodopytlicek]

Nothing? This is quite serious bug isnt it?

[vladimir_krastev]

Hi, thanks for posting. Both lights render with no noise on my setup:



What are your V-Ray and 3ds Max versions? Are you using V-Ray GPU or V-Ray CPU?

[frodopytlicek]

Oh so sorry I absolutely forgot to mention its light cone in enviromental fog not light on ground like you have. Sorry for that.

[frodopytlicek]

We are using Max 24.3 and Vray CPU 6.10.09

[vladimir_krastev]

Hi, still no noise on my end.


The target direct takes more time to clear out with Progressive sampler though. The scene is attached, please compare with yours.

[frodopytlicek]

its Max 24 we are using 22 (24.3 yeah I know its weird ). Check this scene its ours.

[vladimir_krastev]

Hi, the noise with VRayEnvironmentFog and directional lights is a bit more difficult to clear out. If you increase you image sampler's settings it will be eventually gone with the expense of render time. I will ask if this can be somehow improved and get back to the thread.

[frodopytlicek]

Ok but why there is such difference between spot and directional type? There is no way to increase samples just for directional light so you have to increace all samples which is unnecessary because everything else is clean even on low samples setting.

[vladimir_krastev]

Hi, I agree that this can sometimes get you in trouble. I have logged an issue for improving the VRayEnvironmentFog when rendering with directional lights under VMAX-13525 in our system.

[frodopytlicek]

Vray light could have same capabilities than standard ones. We get directional parameter some time ago and now decay. Only parameter missing if shadow softness/sharpness. Then we can forgot about default lights

[^Lele^]

Only parameter missing if shadow softness/sharpness.

This is controlled by directionality and light fixture size (there are a few modes that keep total emitted energy the same, regardless of fixture size.) / fixture texturing.
Cheating it for area lights -to my knowledge- hasn't been done yet by any renderer.