VR FAQ
From Virtools Wiki
Q/ Does your VR Pack provide Framelock?
A/ It depends on what you call FrameLock :
- Framelock as called by NVidia is commonly called Genlock. This is a hardware feature needed to synchronise the vertical retrace of screens.
- Framelock as called by Wildcat is commonly called Swaplock. This is a feature that allows the synchronisation of graphics buffers swapping. This feature can be achieved on the software side with the VRPack or on the hardware side on Wildcat cards only
Q/ What is recommended graphics card?
If you're talking about Genlock, you will need a nVidia Quadro FX card that supports Genlock with a NVIDIA Quadro G-Sync card You can find on nVidia's site a list of cards that support genlock
Quadro Fx 4500, 4600, 5500 and 5600 support both stereo and genlock.
We recommend using one PC per GPU (ie not putting several cards in the same PC, unless you want to boost one card performance through SLI) See this article to understand why.
Q/ What are graphics cards which support Hardware Swaplock using VR Pack?
A/ Hardware swaplock is only supported by Wildcat cards.
Software swaplock is provided by the VRPack and is the preferred solution, as there is no noticeable difference. This solution is used by the vast majority of VR Pack users, including CAVEs, stereo walls etc.
Q/ What are graphics cards which provide Genlock using VR Pack?
A/ The VRPack supports all genlockable cards. Nvidia cards are recommended. You can find on nVidia's site a list of cards that support genlock
Q/ Does the VRPack support edge blending?
Edge blending is provided as a unsupported VRPack sample (starting Virtool 4 SP2), it is still successfully used by a few users.
Q/ Is it possible to drive 4 or more outputs using either a QuadroFX4600x2 or QuadroPlexII ?
Please see the Quadro Plex page.
Q/ Do these devices run in horizontal span across all outputs?
No, horizontal span is only across a single GPU. So you'd have multiple horizontal span displays, one for each GPU.
Q/ If so, can these devices support horizontal span resolutions greater than 4096 wide?
The Windows desktop supports a resolution greater than 4096, but a graphic context can't exceed that value. [on a FX 4500 at least, we haven't tested on newer cards. We believe this value is set by the MAX_TEXTURE_SIZE variable of the graphics card, but this has yet to be confirmed by nVidia] This means you'd have to run multiple VR Players to overcome this limitation. This implies that your composition is working properly on a cluster.
Q/ Is it possible to use the VRPack in Dual View mode? Does this restrict our choice of OpenGL vs DirectX ?
You can run multiple VRPlayer in Dual View mode or Horizontal/Vertical Span mode.
Here's an article about the use of multiple CPU/GPU : http://www.theswapmeet-forum.com/virtoolswiki/index.php/VR_MultiGPU_CPU
Q/ Is it possible to use dual graphics cards with the VR Pack? (eg. two Geforce8800's)
Yes, with the limitations explained here
Categories: VR | FAQ
