vray Dome light with HDRI -> chaotic light spots on model

[aleksandrsnedzveds]

Hi!

 

When I use vray Dome light with HDRI sometimes on model appears chaotic light spots. I tried change settings to remove this spots, but unsuccessful. When I changed the image size or quality spots change location and scale, but they didn't disappear.

 

Please someone help with advice.

Edited March 8, 2016 by aleksandrsnedzveds

[himanshuchoudhary]

Are you using 'store with irradiance map' option on the vraydomelight? If so, try turning it off and render again. You will need to tweak the render settings as well after turing this option off. I used to do this quite a lot in my old studio(faster render times, but wrong process) and the renders used to be splotchy, unless you crank up the IR map settings

[aleksandrsnedzveds]

Thanks for advice, I tried turning off 'store with irradiance map' and change other render settings, but unfortunately it didn't help. Anyway thanks a lot!

 

I found that those light spots appear mostly on glass material (actually behind the glass looking from building outside). I tried change different settings again and again without any success.

 

I attached some previews and render settings. I would appreciate any advice.

[himanshuchoudhary]

Are you using render elements? Maybe that can help point out where this problem is..

[Francisco Penaloza]

it may be quality of your HDRI, try reducing the size of the image and making it a little more blurry for lighting. and use the large sharper version for reflection.

[aleksandrsnedzveds]

Are you using 'store with irradiance map' option on the vraydomelight? If so, try turning it off and render again. You will need to tweak the render settings as well after turing this option off. I used to do this quite a lot in my old studio(faster render times, but wrong process) and the renders used to be splotchy, unless you crank up the IR map settings

 

I don't think that is model or element cause. I made simple test model with similar settings and same HDRI map. All the same. I guess it is HDRI map or irradiance map settings cause.

 

Thanks for your help!

[aleksandrsnedzveds]

it may be quality of your HDRI, try reducing the size of the image and making it a little more blurry for lighting. and use the large sharper version for reflection.

 

Thanks! At this moment I left HDRI only for reflection and using Vray sun for lighting. But in next render I will try to use two Vray lights with two different HDRI maps, one for reflection and other for lighting. Thanks for idea!

[Chris MacDonald]

Have you tried any of this?

 

Use texture – when the Rectangle, Dome, or Mesh light type is used, this tells the light to use a texture for the light surface. If there are surfaces which are close to a texture-mapped light, it is best to have GI enabled. This allows V-Ray to use combined direct and indirect sampling for the light, reducing the noise for surfaces close to the light.

 

Texture – specifies the texture to use. The texture intensity is also affected by the Multiplier of the light.

 

Resolution – specifies the resolution at which the texture is resampled for importance sampling.

 

Adaptiveness – controls the amount to which light sampling is tuned to the texture brightness. If 0.0, no adaptation based on texture intensity is performed. When set to 1.0 (the default), the maximum amount of adaptation is used. Changing this parameter may be required if there are very bright portions of the map, which are however obscured for the particular scene. This will prevent the light from concentrating a lot of samples in this area and shooting too few samples in other parts of the texture. This parameter is ignored when the light type is Mesh, as in that case sampling is not dictated by texture brightness.

[aleksandrsnedzveds]

Have you tried any of this?

 

Thanks Chris for your advice!

 

Finally I solve the problem, but problem was with other settings. Solution was very simlpe.

 

I increase number of Irradiance map interpolation samples setting. I did it before, but I didn't increase it enough.