VrayLight (Dome) Invisiblility and Refractions

[joaquim_montserrat1]

Hi,

I wish we could have more visibility / invisibility options in VrayLight.

I would like the sky to be invisible where alpha = 0 and visible where alpha = 1. Right now, if I check "Invisible" I don't see the sky in the background, but I also loose the sky in the refraction of the sphere.



I would be great to have another checkbox "Affect Refraction" or something like that.
See below the expected result:



The reason for this request: To have this expected result in a compositing software, we have to premult the image. This effectively removes the sky from the alpha, but the edges are not clean. The only way we found to do a clean removal of the sky background is to do a difference merge with the VraySelfIllumination. We could save unnecessary steps when compositing.

A solution to solve this issue in 3dsmax is to set a background refraction image in the Environment settings of Vray and use the dome for lighting only. The issue here is that it's difficult to match the orientation of the VrayLight and the orientation of the Environment Map in Vray settings.

Also, it doesn't make sense to remove the sky from the refraction and still have the alpha at 1. This creates a black refraction but leaves the reflection intact, which doesn't really make sense in my opinion.

Thank you for your support

[hermit.crab]

A solution to solve this issue in 3dsmax is to set a background refraction image in the Environment settings of Vray and use the dome for lighting only. The issue here is that it's difficult to match the orientation of the VrayLight and the orientation of the Environment Map in Vray settings.

Haven't you instanced the bitmap in both slots?

[mathieu_gasq]

Hi,

I have the same problem on Vray 7 !
But the solution with Vray Reflection/Refraction environment doesn't work.

I try to render a drop of water like a rain, and I can't render just my Mesh, without the dome with correct refraction render.
If i put My HDRI map in the environement slop, the refraction is very drark too and incorectly

Can I miss an option in vray to achieve that ?

thanks.

[Vizioen]

Hi,

I have the same problem on Vray 7 !
But the solution with Vray Reflection/Refraction environment doesn't work.

I try to render a drop of water like a rain, and I can't render just my Mesh, without the dome with correct refraction render.
If i put My HDRI map in the environement slop, the refraction is very drark too and incorectly

Can I miss an option in vray to achieve that ?

thanks.

Works fine over here. Can you share a simple scene?

[mathieu_gasq]

Hi,

Thanks for your reply.

My scene : is juste a sphere with glass material, with HDRI in dome light.
When the HDRI is visible :




And here when the HDRI is off :


And i just try with just on sphere and HDRI, it is the same... my refraction is modified by "invisible".
In the MANUAL of Vray, Chaos, explain that is option change the refraction too !

[hermit.crab]

And i just try with just on sphere and HDRI, it is the same... my refraction is modified by "invisible".

Attach the scene with the sphere, please.

[Vizioen]

My setup:
- Create Dome light > VrayHDRI in map slot > Set to invisible, disable affect specular/reflection
- Enable Reflection/Refraction Environment in rendersettings (V-Ray > Environment)
- Instance VrayHDRI map in Reflection/Refraction

[mathieu_gasq]

Thanks,

Sorry, it works with the Reflection/Refraction : It just a problem with multiplier value in Vray Light and Environment. The multiplier in environement doesn't works higher than 1.

Thanks for your help !

[Vizioen]

I agree it's a bit of a hacky way to do it like that and not so flexibel, but to raise the multiplier you can always raise the multiplier in the vraybitmap (Processing > Render Multiplier) or use on output map for instance as well.