V-Ray and PG Yeti. Creating "FurShapeVRay" automatically.

[circus studio]

Hello,

I would to know why VRay create, automatically on rendering, a render collection "_untitled_" with inside somes "*FurShapeVRay".
For instance, in my BG layer, I have somes furs in black hole but I just want furs in primary visibility off.
If I create a collection with these "*FurShapeVRay" in order to contourning this issue, VRay create again a "_untitled_" collection with them.
I need to set up an Yeti or VRay knob?
I use Maya 2018, PG Yeti 3.1.7, and VRay Next upgrade 1.

Thank you,

Ed

[yolov]

Is this with the new Render Setup layers? I don't think V-Ray does anything in particular there. Whatever Maya does with all / most other nodes, it will do to Yeti nodes, with or without V-Ray.

[circus studio]

Hello,

Yes, it is render setup layers of Maya 2018. The elements called FurShapeVRay in the collection.
In another project, I used Yeti with Arnold in the same version of Maya and I don't have this problem.

[yolov]

Thanks, I can get the same here. We'll have a look and we'll try and figure out what the problem is.

[circus studio]

OK, I'm feeling less alone... I'm waiting your feedback.
Thank you.

[yolov]

The _untitled_ collections seems to be handled by the yeti code and we'll send a note to Peregrine Labs about that. It looks like something you can ignore.
For the primary visibility override - can you give me a bit more info - I seem to be able to override the primary visibility and it works.

[circus studio]

OK thank you for your feedback.
For my primary visibility problem, I have one plane ground and one mesh with hair (PG Yeti FurShape). If I put my fur in a VRay object properties set and if I make an override on the primary visibility knob of this set, I don't see the FurShape in my render but I see the FurShapeVRay (into the untitled collection) as black hole (in all channels). But may be it is not the good way to make a primary visibility OFF...

[yolov]

Can you post an image and/or a scene? It seems to work well for me, but I may be missing something.

[circus studio]

OK. How can I send you a scene .ma (I never do this on this forum before)? Private mail?

[yolov]

If the scene is small enough to send over email, you can send it to alexander.yolov@chaosgroup.com.
If the files are large, then you can upload it to something like dropbox or google drive and send me the download link via email.
Or we can provide you with FTP access to upload the scene to our servers.

[circus studio]

OK thank, I sended a scene by mail.

[yolov]

Got the email, looking into it.

[yolov]

Increasing the max transparency levels solves this (from Render Settings > Overrides > Materials).
With primary visibility off, objects are treated as transparent. Since there's lots of hair strands, after 50 intersections, the background color is returned (and by default the max transparency levels are 50).

[circus studio]

Hello Yolov,

I'm still working on hairy character and I search a solution in order to optimize my render time.
You told me when I make a primary visibility off to increase the max transparency level in order to have a good background pass without these blackholes, but my render time explode. In order to have a clean rendering I need to increase this knob over 2000. Not possible in production (more 1000 shots).
Do you have any solution for that? I can't make a hard proxy mesh for furs because too much department will be impacted (modeling, rigging, animation, pipeline), I would a rendering solution.


Another question about primary off in VRay.
If I take 3 spheres in a vop and a transparency max level at 1, the primary off is very clean, perfect, with transparency level at 1 and all the spheres are invisible in camera ray.
BUT if I smooth the sphere with VRay subdivs my spheres are now a black hole and I need to push the max transparency level to 6 in order to find the same result without smooth mesh attribute.
There is a difference between the 2 solutions in render time, the transparency at 1 is faster than transparency at 6. I don't think that is the parsing with a subdiv max at 1 of the spheres but maybe.
Please, could you explain to me why the subdiv mesh change the result and why we need to increase the max transparency level to resolve that?
If Vray can make nice primary off with transparency level at 1, I just want the same result but with the fur and the smooth too...
I don't smooth my furs (dynamique tesselation = OFF, number of segments directly set up in Yeti graph, and I don't have transparency in the shader of it, so I can't understand why I don't have the same result that my 3 Spheres without smooth test (nice primary off with few max transparency level). Please, could you explain to me that? Maybe I missed something.

Thank you by advance,

Best Regards,

Ed

[yolov]

Hi Ed,

We're still looking into this and we'll need a bit more time to be able to reply.
Sorry for the delay.