Visible Bucket Hole in Spotlight Beam

[doppelgaengerdigital]

I am using Maya Spotlight with a very small Cone Angle for Laser Beam Effect. I am using a Volume Grid with Bercon Noise Modulation for light scattering, which works fine.

EDIT:
Thought Light Cache mode renders fine. Also visible artifacts there.

Is it reproducable?

I attached the scene.

Thanks!

[hermit.crab]

This happens when camera rays don't manage to hit the light (due to its size). Increasing the Bucket Min Subdivs should improve it.

[doppelgaengerdigital]

Thabks for the quick response! Yes, this improves the result, but also increases rendertime.

another approach would be to render meshes, right?...but not preferred...
What would be faster in theory, light material or mesh lights?

[hermit.crab]

Yes, I think you create a similar effect with meshes. VRayLightMtl without DI should be the quickest. Add some transparency as well.

[doppelgaengerdigital]

That's what I've tried now. Added ramp to Opacity. It renders quickly and looks fine, also with very thin lines. But it doesn't interact with my fog volume nicely and scattering is also not working.
I tried a mesh light also, but there is the same problem, that the edges of my geo are visible and I can't get nice falloffs and scattering I would like.

Is there any way to improve sampling very small light beams without raising Min Subdivs on Devs side?

best
Stefan

[hermit.crab]

I'm afraid not. Since the fog is barely visible (not sure if intended) raising the min subdivs wouldn't increase render times that much; if it's not black, the min subdivs are likely to be overridden by the max subdivs anyway. Test it out.

[^Lele^]

Is there any way to improve sampling very small light beams without raising Min Subdivs on Devs side?

If there is it isn't obvious.

A raytracer needs to cast rays to know what the contents of a scene are.
Consider it a person throwing darts in the dark, hoping to hit something.
If you force it to throw more than one dart in a specific location to begin with (the min subdivs), they'll have a better idea of where to keep throwing.
One dart is too small to make educated guesses, and so bits of the scene are skipped.

Notice this is visible in this kind of setup particularly, as the rest of the scene is empty.
If there was something else going on behind the rays (say, a textured object), the sampler would likely have an easier time finding the rays as well.

If you're in doubt, use a sampleRate RE to see what's going on with the scene.

[doppelgaengerdigital]

thanks for your feedback! I got good results now, faking the effect with light material and further projecting some bercon noise onto opacity of the material. Looks good and renders super fast!
Makes sense, that the sampler has a hard time, especially on blank backgrounds. This is exactly what I was getting.