white dots in my vray rendering... help!

[sakinadugawalla]

sub-pixel mapping never did the trick for me. what seemed to work was deactivating caustics.

 

good luck everyone...seems to be luck of the draw!

 

Hi, on the vray settings, do I have to deactivate caustics for each light or object? Is there one way I can deactivate caustics with one click of a button. Thanks.

I am using Max Design 2012 with V-ray 2.00.03

[Terri Brown]

Hi Sakina,

 

Open your Render Setup tab, click on the Indirect Illumination' tab, and in the very first window make sure Reflective is unticked (under the GI caustics heading).

 

Hope that helps.

 

All the best,

Terri

[sakinadugawalla]

Hi Terri,

 

Thanks for that. I had already unticked it.

I even manually changed every single material to have the glossy rays from on with GI to Always, as suggested by another user.

Maybe it is still the material that I received from the modeller. I will keep you all posted on the result.

 

Cheers

[sakinadugawalla]

Hello all,

 

So after a week (yes a week: deadline missed!), I figured out all the little things that need to be fixed to avoid this "white-dot phenomenon":

 

under "Render Setup"/F10,

 

1. V-ray submenu:

Image sampler - Adaptive DMC, Filter Mitchell Netravali

Adaptive DMC image sampler, untick DMC sampler threshold and manually select Clr thresh ~0.005 or above, the default 0.1 is too low

Color mapping: type "Reinhard"; multiplier: 1, burn value: 0.9, gamma: 2.2; select only sub-pixel mapping and clamp output, my level was enough at 1, some users increase it to 5.

 

2. Indirect Illuminatuin submenu:

Gi caustics on, but untick reflective and refractive.

Primary engine irradiance map, tick show calc phase and show direct light and randomize samples. subdivs are at your discretion. just remember that interp. samples should be a much lower number to the subdivs. i.e. 40/10 not 40/20. There is an article i read, that says the closer the numbers in size, the less contrast you will have.

Secondary engine light cache, subdivs, higher give you a more detailed/accurate/clearer picture, however your render takes longer, the higher the value. Sample size @ 0.02 works fine, any lower value increases the render time.

V-ray Caustics: untick on

 

3. Settings submenu:

 

Everything can stay the same, however, under VRay System, I unticked "MAX-compatible ShadeContext".

 

This should fix everything. If however, like me, you STILL had issues, then you will have to do what I did:

 

In Material/Map browser, select each material, go to Options submenu, untick "Trace reflections" and "Trace refractions", and go to "treat glossy rays as GI" change that from "Only for GI rays" to "Always".

 

All the best, and thanks to everyone for helping out on this issue.

 

Cheers!

[sakinadugawalla]

Hello all,

 

I posted the same day, but it seems my post was not approved by the moderator.

What solved it was changing the multiplier of the primary engine to 0. It seems that the materials were too complicated so their reflective/refractive attributes were multiplying the amount of light in the scene exponentially.

But yes, GI caustics as mentioned by Terri, sub-pixel mapping and clamp colours are the three most important checks to stop this white-dot effect.

 

Best,

Sakina

[chceen]

Hi,

 

the reason for white dots in a Vray rendering is the following:

 

One or more overbright lights in your scene.

 

 

So if the dots appear check for the following:

 

- Lights with high intensity values

- Hdri with strong contrast or high intensity values

 

If you find it scale the value down (to a defalut like 1 or so) and the dots should disappear

[rashed]

I tried every solution mentioned here but with no luck . Eventually I had to use a different lighting approach because for some reason using vray dome light was causing the problem but any other light type didn't!

[adamkiss1]

I turned off Trace Reflects -> noise disappeared, but render time was much longer, plus no traced colors

 

and it worked only for minutes

Edited June 19, 2014 by adamkiss1

[cesocom]

hi all,

had the same problem and checking "sub pixel mapping" removed the dots but however the accuracy of colors and brightness in some areas in the image (especially shadow areas) was compromised as mentioned in many posts online. So did some more testing and there was another tick that solved the problem for me. In "V-Ray :: Global Switches" inside "Materials" section check the tick "Filter maps for GI". That removed the dots without changing the overall accuracy of brightness and colors... hope this helps someone!

[Jesper Pedersen]

Hi. We had this problem when using a VRay light material on geometry to light a scene.

Tick "Direct Illumination" to ON in the material editor. Also avoid lights emitters being located immediately next to very reflective geometry.

 

Good luck

Jesper Pedersen

http://www.pedersenfocus.ie

[elipan]

And for Vray 3.0 users, solution is very simple these days:

http://www.v-ray.com/features/max-ray-intensity/

 

Really helped me out.

[akmyrzatur]

Ch Ceen was right. If u use vraylightmat select all of them and unchek

[sarahchalek]

I had this problem because the glossiness of my reflective materials was set to 1 and it was concentrating too much light in small points. I lowered the glossiness to .95 and increased the subdivisions to 12 and it seems to be better. I'm doing animation and the white points were flickering throughout my sequence. It's hard to spot when I do test renders because it doesn't show up in every frame. If the white spots persist, I'll try turning on sub-pixel mapping.

[rafaelcarvalho1]

The solution for Vray 3.0 users is ticking the option "Max Ray Intensity" on Global switches.

Unticking the refractive caustics on GI settings also helped me.