vray shadow stress

[Toko]

Hey Everybody,

when i create vray lights with HDR or Softbox map in it i got terrible looking shadows.
(the normal render looks good but the render element shows me many noise in it)

when i switch the lightmap off everything looks good and clean...
i tried everything: really high subdivisons in all lights, switching the sampler modes (DMC...)

any ideas?


the right side shows the shadows without any map in the vray light


thanks in advance
Tommy

[vlado]

It would be helpful if you can provide us with a scene to vray@chaosgroup.com so that we can check if there is anything wrong.

Best regards,
Vlado

[Toko]

thanks for your quick reply vlado! I created a quick testscene with the problem and sent it via email.

[Svetlozar Draganov]

The main parameter to control the noise in this situation is with Adaptiveness parameter in VrayLight.
You can also decrease the noise by using Store with Irradiance Map from VrayLight , but you have to enable Global Illumination with Irradiance Map as a first bounce.

[Toko]

Thanks for your help!
after playing with the adaptivness parameter i saw that this didnt help in every situation, the shadows in my scene looks very bad and noisy.
but i noticed that i helps when i play with the directional parameter in the vray lights. The Shadows looks a way better!

btw. when i work with textures in vray lights (softbox map etc) it would be cool to get a visual feedback...like show map in vieport

[bernhard]

thx for sharing this info...

but one more thing.. what can you do if you render without GI ?
so far I couldn't find any solution in order to fix the noise issue in the VrayShadow element - just cranking up samples can't be really the way to go.

any ideas ?

also.. when using "Store with Irradiance Map" I dont' get my VrayShadow render element - but that's what I want to have for comp purpose.

[joconnell]

Another thing to note is that if the shadow is quite faint, vray's early termination will kick in and not put much sampling into the shadows. If they end up only being a small difference in the final image, you'll often get quite noisy looking elements. When used at their final level, they'll look fine but the actual element itself can often be very grainy.

[simmsimaging]

Another thing to note is that if the shadow is quite faint, vray's early termination will kick in and not put much sampling into the shadows. If they end up only being a small difference in the final image, you'll often get quite noisy looking elements. When used at their final level, they'll look fine but the actual element itself can often be very grainy.

That, and Svetlozar's answers might explain a lot about why my VrayShadow elements are most often totally useless. I always use texture mapped lights.

Svetlozar: I leave the adaptiveness set to the default of 1 - assuming that provides the maximum quality. Is that correct?

[vlado]

Svetlozar: I leave the adaptiveness set to the default of 1 - assuming that provides the maximum quality. Is that correct?

It provides maximum efficiency (samples are only taken when needed for the final image). Maximum quality would be with a value of 0.0 but it might be too slow for any practical use.

Best regards,
Vlado