Geometry goes missing or doesn't update during render: ​​​​​​​

[ian_mayhew]

I've had this issue in several projects where render geometry seems to become "decoupled" with the original geometry.
Sometimes geometry will be "left behind"- where I move something in model space, but after hitting render, the object hasn't moved. Below, the barge, tugboat, and the tow line were all moved in position together:

... But the towline stayed put. I haven't found a way to fix this besides copying/deleting/pasting the object back into place

This seems to happen suddenly, to objects at random, which is not easy to keep track of when doing super large/complex renders with lots of elements.

Other times, things just go missing altogether. A couple hours working back and forth on this ferry render, the hull disappeared.



The hull geometry is clearly visible in the viewport, but I can't get it to render in the scene.

This one is problematic for me, since the boat is a linked block, and inserting/reinserting it into the scene every time something disappears is NOT a good use of my time.
I noticed that switching the renderer from CPU to CUDA makes it come back, but CPU works best for me from an interactive standpoint. Switching back to CPU afterward does not make the geometry show up again. Not sure if that leaves any clues to why this is happening...

This has only started happening to me after the latest update. Is Anyone else experiencing this/know of a way to remedy it?

[ivelina_mincheva]

Hello ian_mayhew!

Thank you for writing us and sharing some examples of the issue.
We can not reproduce it on our side. Is it reproducible in heavy scenes with lots of elements only? Which Rhino and V-Ray versions do you use?
Could you please share a test scene or at least the linked block that causes the "missing" geometry constantly so we would be able to investigate the problem further on? You can send us the packed project (V-Ray>Pack Project...) through our support portal (https://support.chaos.com/hc/en-us/requests/new) with the link from this forum topic in the message.

Thank you.
Kind regards,
Ivelina

[rene_rapati]

In the last few versions of V-ray there have been problems with linked blocks in combination with V-ray geometries and V-ray lights.
See this topic for reference.

It would not surprise me if your problems were caused by using linked blocks. Maybe you can try to insert the blocks instead of linking them and test if the geometry keeps disappearing. Unlinking the blocks can fairly easily be done from the blockmanager in Rhino.
This problem has caused many time consuming problems for me also. Realizing too late in the process that there are things missing from the render. Most of the time this meant doing it all over again and again and again....

[nikolay.bakalov]

Hi,

mind that linked blocks, being blocks by nature, does not support lights. This is a Rhino limitation. Also Scatter guests cannot be part of a block too, since the origin point cannot be deterministically evaluated.

Thus in those cases you must either embed or use worksessions

[ian_mayhew]

I'm using the latest version of Rhino and Vray
Version 8 SR7 (8.7.24121.13001, 2024-04-30)



In the case of the first example-- those are simply curves with the thickness property applied to them. They're not blocked or linked in any way. I can move all of the objects around and they update in the render EXCEPT for the curves... I have uploaded this file, ivelina_mincheva.

I have had similar issues from time to time with other geometry, but I don't have more examples on-hand to share, unfortunately.

In the second example, with the missing hull- I think a layered material went missing-- likely a result of using a linked block. The base material got unassigned- which made the material invisible...

I use layered materials, two-sided materials, and decals fairly frequently, and still have lots of issue with them getting duplicated or going missing (despite what the latest patch notes promised). Linked blocks are important to my workflow in order to maintain revisions in models. They also greatly reduce file sizes so that I can save changes without having to wait (and I'm not going to turn off auto-save either.)

[nikolay.bakalov]

Hi, the curves will not update in interactive due to changes introduced in Rhino 8.6.
look at this topic on the McNeel forum for more info: https://discourse.mcneel.com/t/objec...ring/181057/18

[ivelina_mincheva]

Hi ian_mayhew!

Thank you for sending us the simple Rhino scene and all this important information about the two issues. Using Rhino 8.6, we managed to reproduce both issues. Note that they are not reproducible with older Rhino versions as 8.5, 8.4, etc.

1. The issue with not rendering (Production or Interactive) moved curves/ meshes with enabled Thickening option (as well as Edge Softening, Displacement, etc.) - it is logged in our system as VRW-4450 and a fix will be included in our next released V-Ray version.
2. The issue with the missing nested materials in materials like Bump, Two Sided, Blend, etc. when a linked block is inserted - if this nested materials are deleted from the scene. The new inserting of the linked block will not import the nested materials as it did in Rhino 8.4. This is logged as VRW-4451 and our developers will further investigate it.

Thank you for spending time to narrow down the reasons causing the issues.

Regards,
Ivelina

[yusufcankat_donmez]

I have the same problem even with many simple scenes. Following things happening and these look kind of paranormal a bit:

1. Elements are visible in the scene but not rendering.
2. Elements look weird after moving in the scene, a ghosted copy stays at the previous position.
3. Changes made to the elements don't apply to the render. These elements are not blocks or complicated imported things etc. Very simple geometries without a problem(due to check report in Rhino).

The last versions are unfortunately huge disappointment. Every single day V-ray is pushing my borders. I would still understand if that would happen in the earlier or beta version but this is really bothering.