Mapped Object is partially invisible for no apparent reason.

[Zirnworks]

Hi,

I have a mesh object that's a stack of over 100 plane elements, each with a unique Material ID and mapped with a unique V-ray standard material. Each material is composed of an opacity map and diffuse map (which also controls self-illumination). They are all bundled together into a giant multi-material, which has been applied to the plane object.

These are perfectly visible in the viewport, and yet when they render, they only partially show up! The extent of the problem is dependent on what angle the object is at relative to the camera. I have attached examples.



It appears like some weird draw distance error, but only local to the object. The camera is just a standard Physical camera. This is a very basic scene. Just a simple Vray Sun and Environment map as a light source, and these two are the only objects in my scene. Units are set to centimeters. Each plane is 1 meter x 1 meter square, so it's not like it's huge or anything.

Vray version is Next and Max version is 2017.

Any idea what is causing this and how to fix it?

[yavor.rubenov]

Hello,

What is your Max. transparency levels (Render Setup -> V-Ray -> Global switches)? By default it is 50 which might not be enough if you have over 100 planes. Can you try upping it to some higher value and see if it changes the result ?

Best regards,
Yavor

[Zirnworks]

Hi Yavor,

Setting my transparency levels to number of planes (119) did the trick! They were indeed 50 before. Thanks so much for the quick reply, very glad to have this working.


I do have a related issue: I've been trying to get the GPU render to work for this same "object." According to the documentation, there is no support for changing max transparency levels in GPU mode, so I'm assuming 50 is a hard limit. So I decided to test it with just below 50 (47 planes).

GPU+CPU: Out of memory error, terminated early.
GPU only: Rendered fine

Render mode is progressive. To my knowledge, all the Vray Next GPU settings are default.

I would have expected the opposite. I have 64 gigs of RAM at my CPU's disposal. It had been my understanding that hybrid rendering opens that up for use, so why do I only run out of memory when CPU is enabled? Being able to avoid GPU memory limit errors was a major selling point to me for purchasing Next.

From the "understanding hybrid rendering" article:

"CPU fallback - In case your scene won’t fit into your GPU RAM limits, you can still render on CPU."

Perhaps I misunderstood that? Any insight appreciated.

Thank you again.

[matanov]

Hey,

There is no limit for transparency levels in V-Ray GPU, but that crash is a thing that I want to check - can you send me the scene?

[Zirnworks]

Thank for taking a look.

I sent the file to your email. I played with it some more: It appears that when I isolate 50 frames in their own separate .Max file, I do not get the error. It's only when there are extra assets are in the scene (but off of the camera view) that I get it.

As to the transparency level limit in V-Ray GPU, there indeed seems to be a level limit for me. Earlier on, I was getting the same discrepancies in the GPU engine as I was with the CPU (back when the limit was set at 50). When the planes exceed that number, I also get a weird black box behind the objects. You can see that if you render any of the "full heads" in the file I sent you.