TrackIR V-sync

[Vinkman]

Frame rates at 30 or more are typically fine for a smooth image during gameplay. But I find with TrackIR that a smooth looking image turns studdery as I pan the view around. Speed and smoothness of the image seems to be a function of the pan speed. So for smooth TrackIR operation, frame rates in the 50s seem necessary. Is the head position Sync'd with the refresh rate? or is some mis-match in TrackIR head position updates, causing the choppiness to be worse than it should be?

I have the TrackIr plugged into the fast USB port. Not sure if the slow ports agrivate this issue.

Any thoughts? 

[ImADot]

I've noticed it too. Perhaps technical questions regarding the  way TIR works is best asked of the TIR makers? 

[Vinkman]

I've noticed it too. Perhaps technical questions regarding the  way TIR works is best asked of the TIR makers? 

TrackIr just sends signals to the computer that replicate position vectors. I don't think they have anything to do with when, or how often the game redraws an image. Ah figures that out. 

[Bino]

I have a TrackIR 5 on my computer, but have not noticed any visual stuttering while panning.  I do have most of my USB devices (j-stick, throttle, pedals, TrackIR, web cam) in a powered hub.   

I guess you might try the TrackIR forums?

[The Fugitive]

TrackIr just sends signals to the computer that replicate position vectors. I don't think they have anything to do with when, or how often the game redraws an image. Ah figures that out. 

But it does take up memory and cpu cycles. With my old computer I noticed more and more stuttering. I also spotted other issues and lowered my eye candy a bit here and there and my stuttering went away. With my new computer, I have no issues at all, but this one is a bit of a monster   

My guess is with anything else, as you add more and more to an older system you WILL get more and more issues. They keep adding to the game because everyone wants more and more. You will need to keep adding to your computer to keep up.

[Vinkman]

I think what I'm asking is why the picture looks choppy with a frame rate in the 30s when panning, but doesn't looks choppy when you aren't panning. It's not that the frame rate drops when panning.
It's like when you pan you head, the game is drawing 2 frames in a the "fixed" orientation call it position 1, skipping position 2, then drawing 2 new frames while fixed at position 3 showing smooth motion of objects in the frame, skipping position 4, drawing two frames at position 5, etc....

If the image is updated 30 times a second, and everytime it showed the new position when redrawing, it seems the picture should be as smooth as the motion in the fixed view.

If AH was undersampling the TrackIR relative to the frame rate, then with choppiness might result. When the frame rates are high enough (50s) the panning is smooth. It seems like the pan positions are half the frame rate, creating a choppiness when panning that is doesn't do justice to the actual frame rate.

Have you fellas not experienced that? But now that you mention it, perhaps the TrackIR signal send needs to be V-sinc'd, so it might be a TrackIR issue. I'm just wondering if anyone else has experienced it, and what the root cause might be.

I bring it up because I think it sort of forces TrackIr users to have higher frame rates than snap view users. 

[Skuzzy]

Choppy motion, typically, is associated with slower video cards.  When you simply look straight ahead, the game only loads what changes.  When you pan, every pixel on the screen changes.

The game is smart about what it has to draw.  If your are experiencing choppy panning, then cut down on the graphics and see if it improves.  If it does, then you have narrowed down the issue.  Usually it is video card, but it can also be the CPU.

[Vinkman]

Choppy motion, typically, is associated with slower video cards.  When you simply look straight ahead, the game only loads what changes.  When you pan, every pixel on the screen changes.

The game is smart about what it has to draw.  If your are experiencing choppy panning, then cut down on the graphics and see if it improves.  If it does, then you have narrowed down the issue.  Usually it is video card, but it can also be the CPU.

I hadn't thought it might be a selective redraw. Thanks skuzzy.