High Performane Timer and Rendering Jitter


22-12-2006 00:52:55

Thanks to Bekas, and Ravenger re: the high performance timers.
I was thinking heavily about when I should broach that topic and, got lucky that it was brought up. I am going thru the tutorials, and noticed a problem with jitter.

In Tutorial2 (Mogre) there was a subtle yet distinct pattern of jerky motion / jitter that occurs when I use the left or right key to move the camera. This is much less noticeable when moving forward or back, yet still present.

I know its not my video card or my computer because they are reasonably good (sig below).

I have encountered this issue before, and it was related to excessive calls to render to the video card. I used FRAPS and its showing >600 FPS.
Previously I used a delta timing system, and only called the video card to render 120FPS. But that was using a different engine.

Since I am no expert in this area, I was wondering if you have any suggestion to reduce the # of calls to render? And where would I find the code that actually makes use of these calls so it can be edited?
Or perhaps, I am barking down the wrong tree?

Thanks for assistance,


PS, (I also had this jitter when using an inacurate timer, that for whatever reason could not measure anything less than <= 16ms.


22-12-2006 13:27:46

Addendum: Sig: AMD dual core 2ghz, 1 gig ram 2-2-2-5, WD 160GB HD ATA, Geforce 7600GT.



23-12-2006 23:37:39

See MOGRE tutorial 5 which mentions custom render loops a bit. For more details search around in the main forums.

Also, for the jitter thing, read this: http://www.ogre3d.org/phpBB2/viewtopic.php?p=152891&sid=3117e4919bfe2d40afd1432b0bfb3d29


12-01-2007 21:26:46

Thanks for the tips.

I found that Jitter resolved to nearly undetectable levels when I used the tutorial for overriding the frame listener.

I am not exactly sure why overriding the frame listener would fix the jitter... but suffice it to say that simply overriding it with the supplied code per tutorial #4 did work miracles versus jitter seen in Tutorial #2.

Thanks again.