Vray dome light problem

[neba77]

Has anyone experienced this problem with hdri mapped dome light? I`m getting a lot of grain in the lighting coming from it. Number of samples does not seem to influence the noise levels on it. I`ve cranked up the resolution allso and the problem still exists.

 

Thanks

[Fernando Lino]

you do need to increase the subdivisions under the light parameters

[arquiteck09]

maybe is the HDRI itself, some times the results are to noisy because of the amount of information. Maybe.

[Christopher Nichols]

If you have a super bright HDRI you will need some serious AA. The best way is to follow the Universal Settings senario outlined by vlado here:

 

http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=14747

[hyperfocaldesign]

Try using a seperate, invisible, smaller, possibly blurred HDRI for your lighting, this seems to be a universal fix in software that has this problem. Hope that helps.

[Razorback]

Try using a seperate, invisible, smaller, possibly blurred HDRI for your lighting, this seems to be a universal fix in software that has this problem. Hope that helps.

 

How should we blur the hdri? I tried applying blur filter in photoshop but the noise still exist in my image. Can you elaborate how to fix this by using blurry hdri.

 

TIA

[Andrew1]

try resampling it adding more dpi this should smooth it out, then blur it.

Cheers!

[Christopher Nichols]

It is all in the AA settings. Use qmc AA with 1/25 and a clr thrsh of 0.002 for the best quality. For ok quality try 1/16 0.005

[Razorback]

It is all in the AA settings. Use qmc AA with 1/25 and a clr thrsh of 0.002 for the best quality. For ok quality try 1/16 0.005

 

Thanks Chris, what you are saying is that I don't really need to blur my sachform hdri in photoshop is that right? I just need to adjust my AA settings and that will clear the issue? Will the change of AA settings affect my render time and how does it compared to a blurred hdri that they are talking about.

 

My AA setting that produces a lot of noise is adaptive subdivision. Thanks in advance for further input.

 

Just tried it a while ago and Chris settings really helped clear the issue the only downside is the render time increases a lot.

 

Thanks again Chris.

[brobins]

Hey,

 

I am having the same issues with HDRI mapped dome lights.. A lot of noise in the lighting, I can reduce it by lowing the noise threshold to 0.003 or lower but as said above, render times are shot!

 

Would using a much smaller and blured HDRI for the lighting only help these issues?

 

Thanks

[Stephen Thomas]

The dome light will give you much better results, but also more noise issues to deal with, which means lowering your colour threshold and/or upping your AA settings as Chris suggested. However if you are using an HDRI with a large dynamic range it really is your only option as you can see by the tests I did here: http://www.cgarchitect.com/vb/25080-vray-dome-light-ibl.html

 

Creating a small blurred version of your HDRI will give you a smoother GI solution and reduce render times. You might be interested in this plugin which creates all your different maps for you. Full-res LDR image for background, half-res HDR image for reflections and 360x180 blurred HDR for GI lighting. It will even load the maps using a vray HDRI map into the correct slots and set up a sunlight for you in the appropriate position using colour and intensity values from the HDR. Well worth checking out!

 

http://www.hdrlabs.com/sibl/index.html

[brobins]

Hey,

 

Thanks for your reply.. I will check out that plugin, it looks promising!

 

Out of interest how to do usually set yours up?

 

I am using a Dome Light only effecting specular and reflection, Not effecting Reflections. Then I have the same map in the reflection overide.. Thats about it..

 

Thanks,

 

Ben

[Stephen Thomas]

Hey,

 

Thanks for your reply.. I will check out that plugin, it looks promising!

 

Out of interest how to do usually set yours up?

 

I am using a Dome Light only effecting specular and reflection, Not effecting Reflections. Then I have the same map in the reflection overide.. Thats about it..

 

Thanks,

 

Ben

To be honest I normally just drop a vray hdri map in the environment slot. I don't really use any HDRs with that great a dynamic range that it becomes a problem. I generally use the vray daylight system anyway, though sometimes I replace the vray sky with an HDR. 9 times out of 10 I wouldn't use the HDR for my background image. Either just vray sky or comp in a background in post.