# Quad-buffer (Crystal Eyes) not working on Linux
**URL:** https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948
**Category:** ParaView Support
**Created:** [November 10, 2019, 5:42pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948 "2019-11-10T17:42:39Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@steve](https://discourse.paraview.org/u/steve)
#### Post date: [November 10, 2019, 5:42pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/1 "2019-11-10T17:42:39Z")
The release notes for Paraview 5.7.0 says quad-buffer stereo (Crystal Eyes)
active shutter glasses work. However, I can not get “Crystal Eyes” stereo
working with Paraview 5.70.
I am installing Immersive Paraview on a traditional CAVE configuration at NIST.
```
3 Walls (Front, Left, Floor) in a corner arrangement
Nvidia Quadro RTX card 4 outputs:
X11 Display numbers -
:0.0 Console LCD flat panel
:0.1 Front projector
:0.2 Left projector
:0.3 Floor projector
CentOS 7.7 Linux
Also same problem on a problem on a home system:
Nvidia Quadro P1000
X11 Display numbers: :2.0 Console, :3.0 Front, :4.0 Left, :5.0 Floor
LCD monitors on all
Fedora 30
```
I believe I have the card, cables and driver properly configured since
glxgears works properly using this command.
```
mpiexec -env="DISPLAY=:0.1" /usr/bin/glxgears -stereo $config : \
-env="DISPLAY=:0.2" /usr/bin/glxgears -stereo $config : \
-env="DISPLAY=:0.3" /usr/bin/glxgears -stereo $config
```
I have tried a three process mpiexec pvserver and just single process started
with
```
praview --stereo --stereo-type="Crystal Eyes"
```
All other stereo modes work when selected in the GUI. I suspect I am seeing
just one eye. I not entirely sure I have a correct config.pvx file.
I have adapted the one cave.pvx example.
Are there any other config file examples?
Any suggestions on what I should do to get Crystal Eyes stereo working?
Thanks
---
### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [November 11, 2019, 3:32pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/2 "2019-11-11T15:32:37Z")
@steve, can you provide information on how you’re launching your pvserver processes and also the cave.pvx file you used?
Note the 5.7 Quad-buffer note only refers to the Qt client supporting quad buffer. The support for stereo on the pvserver processes – which is what you’re relying on in this case – should be large unaffected by these changes.
---
### Author:  [@steve](https://discourse.paraview.org/u/steve)
#### Post date: [November 12, 2019, 1:45am UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/3 "2019-11-12T01:45:59Z")
Is the problem that I am using the pre-built binary?
After executing the start up script, in another window I type:
```
paraview --stereo --stereo-type="CRYSTAL EYES"
```
My start up script an cave.pvx are below.
Thanks,
Steve
Here is my server start up script
```
#! /bin/bash
# ParaView-5.7.0-MPI-Linux-Python3.7-64bit is from pre-compiled binaries
export PARAVIEW_ROOT=/home/steve/localtmp/ncsw/PV/ParaView-5.7.0-MPI-Linux-Python3.7-64bit
mpiexec=${PARAVIEW_ROOT}/bin/mpiexec
pvserver=${PARAVIEW_ROOT}/bin/pvserver
config=./cave.pvx
$mpiexec -env="DISPLAY=:1.1" $pvserver --stereo --stereo-type="CRYSTAL EYES" $config : \
-env="DISPLAY=:1.2" $pvserver --stereo --stereo-type="CRYSTAL EYES" $config : \
-env="DISPLAY=:1.3" $pvserver --stereo --stereo-type="CRYSTAL EYES" $config
```
Here is cave.pvx
```
```
---
### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [November 12, 2019, 6:43pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/4 "2019-11-12T18:43:43Z")
> [@steve](#):
>
> Is the problem that I am using the pre-built binary?
That should not be it.
I am looking into it now. I think I am able to reproduce the issue. I’ll keep you posted as I learn more.
---
### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [November 12, 2019, 9:53pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/5 "2019-11-12T21:53:16Z")
Try launching pvserver with the following arguments as well: `--stereo --stereo-type="Crystal Eyes"`. The arguments are currently needed for both the client and the server processes.
---
### Author:  [@steve](https://discourse.paraview.org/u/steve)
#### Post date: [November 13, 2019, 7:03am UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/6 "2019-11-13T07:03:01Z")
That is what my script does and I have run the paraview command with the two parameters. I have tried evry combination I can think of. Am I missing something?
Just to summarize:
using mpiexec I run 3 copies of pvserver
I run a single copy of paraview
I specify both stereo args on all.
What else should I try?
Thanks,
Steve
---
### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [November 13, 2019, 1:04pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/7 "2019-11-13T13:04:09Z")
That’s strange; specifying stereo args to both processes did the trick for me with ParaView 5.7 binaries from [paraview.org](http://paraview.org).
Looking at the code, the arguments are case sensitive. So trying using `--stereo-type="Crystal Eyes"` and not `--stereo-type="CRYSTAL EYES"`.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [November 19, 2019, 4:55pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/8 "2019-11-19T16:55:14Z")
I reproduce. My cave setup worked Perfectly with ParaView 5.6.2, but not with ParaView 5.7.0.
I will bisect and see where does this come from.
@steve : You mention a NVIDIA Quadro P1000 card but also RTX cards ? Afaik RTX doe not support Crystal Eyes. Your quadro should supports it though.
---
### Author:  [@steve](https://discourse.paraview.org/u/steve)
#### Post date: [November 19, 2019, 6:47pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/9 "2019-11-19T18:47:00Z")
Its a Quadro RTX 8000 running the Nvidia driver 435.21
No that I am using exactly “Crystal Eyes” as the stereo type, I getting stereo.
I’m in the process of creating the correct connections in the VRplugin to VRPN. I will start with the example on the immersive Paraview wiki. If anyone has any additional examples or documentation, please pass them along.
-Steve
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [November 20, 2019, 8:27am UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/10 "2019-11-20T08:27:32Z")
Great news !
Does it works with the P1000 as well ?
You can find VRPN examples here :
[https://www.paraview.org/Wiki/Immersive\_ParaView](https://www.paraview.org/Wiki/Immersive_ParaView)
>
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [November 20, 2019, 4:04pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/11 "2019-11-20T16:04:48Z")
> [@utkarsh.ayachit](#):
>
> The arguments are currently needed for both the client and the server processes.
This is what I missed in my own configuration. it is working perfectly here as well.
---
### Author:  [@steve](https://discourse.paraview.org/u/steve)
#### Post date: [November 20, 2019, 5:14pm UTC](https://discourse.paraview.org/t/quad-buffer-crystal-eyes-not-working-on-linux/2948/12 "2019-11-20T17:14:44Z")
Yes, Crystal Eyes stereo is working on my Quadro P1000.
Note: My xorg.conf is set to create DISPLAYs :1.0 :1.1 :1.2, :1.3 and the P1000 system have common
flat panel monitors and not stereo capable projectors. So I declare its working based on seeing
the double images on the monitors.
Also, I don’t see double images on :0.0 were the paraview client runs. I do see the double image
on :1.1, :1.2, :1.3 (my simulated cave walls).