Rhino + Vray Frame Buffer Window AWOL?

This seems like a semi common issue but I dont know what is going on… Does anyone know what to do when the VRay frame buffer window (the panel that shows the rendering!) disappears and won’t return upon selection? I can see the rendering in the windows preview but nothing happens when I click on it, it doesn’t open.

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Chaos got back to me and I ended up deleting a Temp file thats created when the program runs. That has worked well and Im not having the problem anymore.

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Thanks for conveying the fix… do you recall the temp file name and location?


I do not know the full details of this ticket, but I do know the FrameBuffer state is stored in a (CSIDL_APPDATA) folder:

C:\Users{$user}\AppData\Roaming\Chaos Group\V-Ray 3.4 for Rhinoceros 5\FrameBufferState.fbs
C:\Users{$user}\AppData\Roaming\Chaos Group\V-Ray 3.4 for Rhinoceros 6\FrameBufferState.fbs

If the file gets messed up (via crash, etc) the V-Ray Frame Buffer will fail to display correctly, an easy fix is to delete that file.


Thanks Matt!

Hi Dave, I have the same problem. Do you have the information from Chaos about deleting the Temp file ? Deleting the fbs-file (as mentioned below) doesn´t work! Thank you.

Is it possible that the frame buffer window is in your “second screen”?

In that case, you can move it back in the first screen by clicking in the preview of the vfb in the window bar, then click move, and press ctrl+right arrrow on the keyboard,


Thanks, this worked for me!

Worked for me, Thanks!

Thanks, worked for me as well.
But this happens with Light Gen also sometimes. Anyway i can fix it?

Currently all windows are shown at the center of the primary display. Only the VFB location and size is recorded thought, and is persisted across multiple session. This also means that if your display layout get changed between two session the VFB may “disappear”. It is actually located outside the bound of the current monitors surface. There are couple of ways to fix the problem.

  1. You shall still be able to see the VFB in the taskbar. From there you can “Maximize” the VFB. Windows will move the VFB to the nearest monitor, and you will be able to see it. Then a simple “Restore” will have the effect of moving the VFB to the nearest monitor.
  2. Since V-Ray 6 there is a menu command that allows you to reset the VFB State
    This shall have the same net effect as option 1.

All other UI windows are always displayed at the center of the primary monitor. If your display topology changed during an active session, some windows may be left outside the current surface. Couple of options to fix that as well:

  1. Same as with the VFB option 1
  2. If “Maximize” is not available (some windows cannot be maximized) use the “Move” option. Windows will automatically move the cursor to the center of the title bar of the stranded window and enter a Move mode. Your cursor will be out of view. You just need to click and drag the mouse around until it gets into view.
  3. You can release the V-Ray license. This will also terminate all UI windows. Upon reengaging the license, by attempting to show up the wanted window, the UI process will restart and place the requested window at the center of the primary monitor

Currently we’re working on a small enhancement to place the UI window at the center of Rhino’s main window, instead of the center of the primary monitor. I hope we have that by the next release.