CAVE screen lag

[brunomartelli]

Hi

Im wondering we've got 12 projectors in the CAVE, but when navigating now there is a sort of lag in some of the screens sometimes. We have updated to latest vizard etc. Any ideas what it might be? or what to look at? (it didnt used to do this so something else may have changed)

[Jeff]

Are you running the same scenes as before? What is the framerate when you notice the lag? You can see the framerate if you press F4 with the script running. How are you syncing the machines, through Quadro G-Sync or Vizard's cluster application?

[brunomartelli]

Yes running same scene, machines are synced with Vizards Cluster app

with clustering 30fps, without 190fps
with clustering (no sync frames) 44 - 60fps

[brunomartelli]

Originally Posted by brunomartelli

Yes running same scene, machines are synced with Vizards Cluster app

with clustering 30fps, without 190fps
with clustering (no sync frames) 44 - 60fps

(((message wants 10 more characters)))

[Jeff]

Do you notice lag if both the Sync Frames and Sync Draw options are enabled with your scene?

Is there an issue with lag if you run a simple scene with clustering and sync enabled? What is the framerate in this case? Try the following code:

import viz
viz.go(viz.FULLSCREEN)

viz.add('dojo.osgb')

import vizcam
vizcam.PivotAnimate()

[brunomartelli]

ok that runs fast but there is no stereo...

[brunomartelli]

back to my scene. with no sync frames and sync draw the fps is higher but variable, with sync frames and sync draw the fps is lower and also variable.

my scene has a large number of landscape tiles. many are not visible because of LOD helper in the OSG file. Is it possible to dynamically load tiles when needed???

[Jeff]

If your scene does not render at 60 fps then enabling sync in the cluster application will lower the framerate because all machines will wait for the slowest one. If you don't enable sync some of the machines may run faster but then they will be out of sync. To keep all screens in sync and maintain a high framerate you'll need to reduce the complexity of your models or optimize them. Here are some articles that maybe helpful:

Drawable Budget
Polygon Budget
Texture Budget
GPU Budget Intro