Vray Dome Light + HDRI = White Dots

V-Ray for 3ds Max V-Ray for 3ds Max :: Issues
1

Hi!

I’m rendering an interior scene. Light Rig is simple:
-VraySun light
-Vray Dome light with a VrayHDRI texutre on it

I render using BF+LC (Universal Settings). there are a lot of white dots all around the scene, above all near the window where the light enters, both on reflective and lambertian surfaces.

If I switch off Dome light, white dots disappear. If I check “Sub Pixel” they disapper too, but the scene is a lot darker and I’ve to reset everything…

Which should be the origin of the problem? the .exr file?

Thank you.

2

How many subdivisions for Dome?

3

if you’re using vray 3, there’s a max ray intensity value that you can set under global switches. low numbers can help in this case, as the bright dots are likely caused by vary bright rays coming from the hdr map.

4

You could also try blurring your HDRI map for lighting (not for reflections, use two dome lights if you have to, one for reflections, one for lighting).

5

Thank you for your answers.

The “solution” in this case is to uncheck “Clamp” checkbox. I don’t know the reason why checking it with a value of 1.0, the Dome light reacts in this way.

Why the Dome reacts in this way? What happens between the Clamp and the Dome? Perhaps the Dome is jelous 'cause the Clamp and Subpixel are too much near? mha…

6

It would be helpful if you can post an image.

Which clamp option did you uncheck? If it’s the color mapping one, clamping to 1.0 is not a good idea generally; something like 4 or 5 is better.

Best regards,
Vlado

7

I’ve had the same issue when I’ve lowered the Gamma on an HDRi to increase the suns power, its the very white values in the reflections that make the spots. I found lowering the Domelights value helped a lot, other than that I just need a shed load of subdivs. The MRI did not help even at 1.

8

Here Vlado you can see:

Clamp ON:
www.ossosso.com/scambio/pecci/clamp_on.jpg

Clamp OFF:
www.ossosso.com/scambio/pecci/clamp_off.jpg

Anyway I want to resume possible solutions:
-Lower Hdri intensity
-set Clamp Off
-set Sub Pixel Mapping ON (image darker)
-lower Max Ray Intens.

9

The effect that you get look strange.
Would it be possible to send/attach a striped version of the scene (just the walls in example)? Usually one should get a speck-free result when Clamp (Color mapping) option is enabled.