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