Opacity map in MSO causing refraction problems in Vray 1.5

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

I found that a MSO material in Vray 1.5 that contains a material with an opacity map causes unwanted effects to materials with refraction in that MSO (namely glass). Here is a render straight out of Max 8 Vray 1.47:

Max8Vray1
Max8Vray1800×600 38.9 KB

And here is the exact same scene rendered in Max 9 Vray 1.5

Max9Vray1
Max9Vray1800×600 43.6 KB

The body of the car is one MSO with 13 material/IDs, the last of which is for the Honda logo and contains an opacity map. As you can see, the refraction in the glass is incorrect in this render. When I clear the opacity map from the Honda logo, the glass is fixed. The glass has a thickness of 1/8" and the material has real world IOR and is correct. The MSO always worked fine in 1.47. It is not a corrupted material, same results when I put any glass material in a MSO with a material containing an opacity map

2

I think the bug was in 1.47, but now the RC looks wrong because it was set up to work with 1.47.

3

I get the same results when I rebuild any MSO that contains glass and another material with an opacity map (bitmap or procedural texture) in the RC. This never happened in 1.47. Also, worth pointing out, they are all Vray materials.

4

Oh, sry, there are two different issues here, One being a diffrerence in reflect/refract energy and the other is a problem with “affect shadow” not working within a MSO this is fixed in the internal releases there is a work around for RC3 http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=17187&highlight=affect+shadow+blend

5

Thanks, that worked! Worth noting, you mentioned this is a RC3 work around. We are using RC4 and still need the workaround. Anyway, thanks again.

6

This seems to work fine in the latest versions of RC4.

Best regards,
Vlado