IPR: Material with Fog Color renders black

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

Got a problem with IPR: two objects which have a material with Fog Color applied render black in IPR.
It renders fine in ADV, also with progressive sampler. Trace depth is 12 in both cases. the inside of the glass screen has a BlendMtl for the primer at the edges. But even if I set blend amount to 0, it still doesn’t work. Please take a look at the attached images. Is this a known bug?

adv_v01.JPG
adv_v01.JPG1160×876 89.1 KB
ipr_v01.JPG
ipr_v01.JPG1476×1108 119 KB

Max 2017, V-Ray 3.60.03

Regards

Oliver

2

No, I’ve never seen that. Can you post the scene? What kind of object is it? Does it have any modifiers (f.e. Shell) that are set to render-time only?

Best regards,
Vlado

3

Here are the parts. Just place any image into the environment background so to see through see glass.
No modifiers apart from a UVW map.
ipr_fog_problem_01.zip (858 KB)

4

Our colleagues managed to reproduce your issue and it was reported as a bug to our system. We will inform you when we have any progress on it.

5

Okay, thanks.

6

Is this bug fixed in any one of latest releases?

7

I remember we looked into it, and the problem was something about the 3ds Max Falloff map, as far as I remember. Not sure it’s fixed though - will check. We have similar issues with the 3ds Max boxed mapping texture.

Best regards,
Vlado

8

Well, the materials in the scene I sent to you do not have any falloff texture in any of the shaders. Good to know, none the less.

9

So the actual reason is a bit more convoluted as our QA guy pointed out. The upper geometry has a refractive material applied. The one below has a blend material with the same refractive material as base. It seems that the normal Adv renderer “sees” the geometry at the bottom as part of the same material/geometry and makes it refractive like it has volume, while IPR treats them like two separate materials thus making the upper geometry black. We need to figure out what to do about that.

Best regards,
Vlado

10

I will try to join the two surface and see what happens.
Thanks so far!

11

They need to have the same material; it’s not necessary for them to be one object. You can maybe use VRayMultiSubTex to have different properties on the surfaces.

Best regards,
Vlado

12

Bug is still not fixed in Next.

13

Is the issue somewhere on the to-do-list?

14

Very OT Oliver but how do you manage to render a viewport background? When i plug an image to viewport background i get black render everytime. Or did you mean the evnironment and not background?

15

Yes, it is.

16

Sure, environment background. The viewport background (alt+b) is just for display purposes in Max viewport, it will not get rendered