Multi/Sub-Object Problem

[digitalmediatechnik]

I've recently had to do some changes to an old project done with Vray 2.4.
Some of the objects are using the standard Max Multi/Sub-Object using standard Max materials. Very basic stuff.
In Vray 2.4 these rendered (& still render) fine. In Vray 3.6 the flipped faces of the object are rendering black.
The first example here has 2 material IDs with identical materials assigned to each. The second example has the same material applied to the whole object (no multisub object). Swapping the materials for Vray materials solves the problem but is a crazy amount of work & it will likely not exactly match what was done before.
At the moment I am lucky to still have a working 2.4 installation but it's in an earlier version of Max which also isn't ideal.
What has changed between 2.4 & 3.6 to make it behave like this?
Anything I can do without going back and flipping faces or converting materials to Vray mats? Any magic setting or button to click on?

[Miro]

Looks very similar to an already reported and logged as a bug issue, but to be sure - can you share the scene with that object to support@chaosgorup.com?

By the way, you can avoid the manual work and convert those standard materials to VRayMtls automatically with the V-Ray scene converter tool.

[flino2004]

try...explode by element.

[digitalmediatechnik]

Looks very similar to an already reported and logged as a bug issue, but to be sure - can you share the scene with that object to support@chaosgorup.com?

By the way, you can avoid the manual work and convert those standard materials to VRayMtls automatically with the V-Ray scene converter tool.

I sent you a mail Miroslav!

Interestingly, I found that the problem only occurs when there is a light in the scene. No lights means no problem (which is not a solution!).

[digitalmediatechnik]

try...explode by element.

Not sure I understand what you mean? You are not suggesting going into each model and editing the direction of the faces are you?

[Miro]

Looks like the 2-sided option of the Standard material is not considered when it's plugged in a Multi/Sub-object node.
It's logged in our bug tracker and we'll post here when we have any news.

[digitalmediatechnik]

Looks like the 2-sided option of the Standard material is not considered when it's plugged in a Multi/Sub-object node.
It's logged in our bug tracker and we'll post here when we have any news.

But only when a light is present which seems a bit weird...

[flino2004]

Select the object and then explode it by elements...you still have one object after doing that but the elements are not attached to each other. I got something similar once in a while and doing that I revolved.

[digitalmediatechnik]

Select the object and then explode it by elements...you still have one object after doing that but the elements are not attached to each other. I got something similar once in a while and doing that I revolved.

I've got hundreds of archive scenes with sometimes thousands of objects in each. It's just not practical as a solution. Anyway, the guys are working on it and I'm confident a fix will be forthcoming (no pressure guys )

[padre.ayuso]

Looks like the 2-sided option of the Standard material is not considered when it's plugged in a Multi/Sub-object node.
It's logged in our bug tracker and we'll post here when we have any news.

But.... why.... just convert the scene materials to VRay materials, right? I have had buckets stuck on Standard Materials for hours, not worth the "handling of bug" just get rid of all standard materials, no? Unless there is an advantage to Standard materials I'm not aware of?

[anthonyh]

There are a few uses for standard materials in some situations, we use it for matte passes. I understand the scene converter argument but Vray states standard material compatibility (aside from raytrace/reflect and a few other situations) so I would expect it to work, at least until Vray states otherwise which is always a possibility.

[digitalmediatechnik]

But.... why.... just convert the scene materials to VRay materials, right? I have had buckets stuck on Standard Materials for hours, not worth the "handling of bug" just get rid of all standard materials, no? Unless there is an advantage to Standard materials I'm not aware of?

If it was just one scene then I could maybe accept that approach. But if I want to do a small change to an old job with multiple xref models I don't want to have to go through all the models converting the materials. It's madness.

I could understand if it never worked but it worked fine in v2.5 and every version before that including the first versions of VRay free! Something changed in v3 that broke it & the solution cannot be going back & converting more than 10 years of models. In the absence of a fix I'd rather do that work in v2.5 which luckily I still have access to.

[padre.ayuso]

If it was just one scene then I could maybe accept that approach. But if I want to do a small change to an old job with multiple xref models I don't want to have to go through all the models converting the materials. It's madness.

I could understand if it never worked but it worked fine in v2.5 and every version before that including the first versions of VRay free! Something changed in v3 that broke it & the solution cannot be going back & converting more than 10 years of models. In the absence of a fix I'd rather do that work in v2.5 which luckily I still have access to.

Makes sense.

[digitalmediatechnik]

Any news on this?

[digitalmediatechnik]

Still nothing on this?

This problem is stopping me moving fully to Vray 3 and will currently stop me upgrading to Vray Next.

I can understand problems implementing new features or getting something new working properly but this works in v2.5. It's a bit bizarre that it still can't work in v3.

Please don't let this problem just be forgotten about!