Mesh light casting self shadow issue

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

Hello,

quick question…since when does the mesh light cast a self shadow???

Please have a look at the image below, inside the chandelier there is a box mesh light and its quite evident on the light fixture that the mesh light is casting a shadow of itself.
If i use vray sphere light its not doing this…is this a bug or a property of a mesh light? Should not the mesh light be actually shining from behind the fixture?
The light fixture is double sided material - actually a shelled object with a 0.5mm thickness.
Is there any way to avoid this? So the light behaves like the sphere light???

Thanks for the pointers
Martin

mesh light.jpg
mesh light.jpg760×354 68 KB

2

Hi,

This seems to be a problem in the latest official versions, but I think there is some improvements and fixes ready to be added for the next service pack release. Can you post or send this scene to support@chaosgroup.com to verify that? I just want to test with your setup.

3

It’s not a bug, that’s how the mesh light works generally. You will get the same result if you model six separate plane lights.

A solution could be to make the mesh light not a box, but some slightly rounded geometry.

Best regards,
Vlado

4

Here is some comparison with six plane lights vs a box mesh light…

Best regards,
Vlado

plane_lights.png
plane_lights.png640×480 40.8 KB

mesh_light.png
mesh_light.png640×480 40.1 KB

5

It does the same thing when i make the mesh light out of a capsule object…still casts self shadows…anyway, i will send part of the scene for sure in the morning