Rectangle light gets cut off in environment fog the more directional it is

[evanerichards]

Is it expected behavior that a rectangle light gets more and more cut off the more directional it is?
Is there a way to keep the beam from getting cut off like that? Please advise.
Thanks!

Please refer to the below images to see what I mean.

Directional = 1


Directional = .99


Directional = .95


Directional = .75

[yolov]

What's the image sampler settings for this image? If you're using bucket sampling with min subdivs 1, can you try raising the min subdivs and see if that helps?
You could also check if rendering with and without adaptive lights makes any difference.

[evanerichards]

I was using bucket subdivision. I'll try switching that up as well as rendering without adaptive lights and report back if any of those things help.

Thanks!

[yolov]

What V-Ray build are you using, actually? If it's old(-ish) you could try a newer nightly, there's a good chance that this has already been fixed.

[evanerichards]

I'm on 3.52.01 (OSX)

[evanerichards]

None of these things worked.
I changed the lights from adaptive, I turned minimum subdivs to 8 in bucket rendering, and I tried progressive rendering. All three renders looked the same as the images I posted

[vlado]

Ok then, can you try a nightly build, and if that fails too, I will need a scene so that I can fix it.

Best regards,
Vlado

[evanerichards]

Sure thing. I'll give the latest nightly build a try tonight and let you know what I find.

[evanerichards]

Latest nightly build didn't change anything. Here's the scene file.


WeirdLighting.ma.zip

[vlado]

Thanks, I'm looking into it.

Best regards,
Vlado

[damaggio]

Hi evan, I was curious about your issue since I use fog quite often, I tested here and see the same result on the latest build, I found out having directionality set to 1 leads to this artifact and also makes the area light not visible, if you switch to Disc the artifact seems to go away and light source is still visible.
Lets see how Vlado responds...gotta get back to work.
Good luck.

[evanerichards]

Yes, I experienced the same thing. Glad to hear it's not just me
The artifact also gets more and more pronounced the more directional (closer to 1) the light gets. Good to know I can turn it to disc shape and have the artifact go away. That may be what I end up doing in the meantime.

[evanerichards]

Hi evan, I was curious about your issue since I use fog quite often, I tested here and see the same result on the latest build, I found out having directionality set to 1 leads to this artifact and also makes the area light not visible, if you switch to Disc the artifact seems to go away and light source is still visible.
Lets see how Vlado responds...gotta get back to work.
Good luck.

Funny. Switching to the light disc did not solve the problem for me. I wonder why it worked for you?

[damaggio]

I haven't tried again since last time but set up a new scene and test it again, don't use the same light as before, there could be some issue when that light in particular when it was created.....just a thought.

[evanerichards]

Has this problem been resolved? I've been doing a lot of lighting with fog and am finding it difficult to shape the fog the way I'd like with the light directionality being so finicky.