2

I'm having an issue with a path animation. I have a root object, with a number of children, animated on the path. My problem is, the further down the path I go, a jitter develops in the parented geometry. I have linked a video of the problem. http://sean.novak.us/vid/help/jittersAlongPath.mp4

Sean Novak
  • 195
  • 2
  • 8
  • Are there any other constraints in play? – Robin Betts Sep 22 '20 at 21:19
  • 1
    Looks like float point precision issues as you move away from scene origin – Duarte Farrajota Ramos Sep 22 '20 at 21:29
  • The character armatures use constraints to follow the seats. However, the ship geometry is parented to the animated path constrained object. – Sean Novak Sep 22 '20 at 21:29
  • @DuarteFarrajotaRamos, I thought the same thing, until I scaled down the whole scene by 0.1. If it was only a relation to 0,0,0, I think I would have observed SOME change. This makes me think it has something to do with the transformation along the curve. – Sean Novak Sep 22 '20 at 21:31
  • 1
    What type of curve do you use? I've heard a few instances of Bezier Curve internal math leading to precision issues, and Paths being better for animations – Duarte Farrajota Ramos Sep 22 '20 at 21:37
  • @DuarteFarrajotaRamos, I am using Bezier. I'll switch and see if it helps. Thanks for the suggestion! – Sean Novak Sep 22 '20 at 21:40
  • @DuarteFarrajotaRamos, I'm back to thinking it's your first suggestion, the float point precision issue. While the path seems like it helps a bit. If I ONLY scale down the path, the jitter lessens. However, It seems if I scale down the geometry as well, the jitters return. I think I need to apply transformations to all of the geometry to get it right. Uffff.. this is going to take a while. – Sean Novak Sep 22 '20 at 23:18
  • That's not it either. Applying scale did nothing. I'm guessing the shorter path, with larger geometry is less noticeable, simply because the geometry is larger and the jitter is less noticeable. If I scale the geometry in proportion to the path, the jitter remains the same. Distance from world origin makes not difference. – Sean Novak Sep 22 '20 at 23:58
  • Ufff, I ended yesterday unsuccessful. To get around this issue, I'm just going to render the camera rig on the path. Then composite the ship interior and characters as a separate render. I'll probably loose fidelity in the animated reflections, etc. But, I'll try to fake the lighting by animating them to match rotations etc. What a pain! – Sean Novak Sep 23 '20 at 08:49

2 Answers2

0

Turns out, this IS in fact a floating point precision issue. Not something to do with the math along the path, itself. In an effort to keep my vehicle and camera near the world origin, I created a root object, parented my environment and path to it, then animated it's location to try to keep the vehicle near to 0,0,0. It has helped a LOT! Here is a video, outlining the solution and result: http://sean.novak.us/vid/help/jitterSolution.mp4

Sean Novak
  • 195
  • 2
  • 8
0

Hi I saw your solution to the jittering problem, which I have now too. Can you explain it better? I think you created a world origin object and parented all your objects in the scene... I'm not sure what do you mean by "world origin object"... Thank you sir.

Michael Bell
  • 1
  • Hi Michael, did you watch the video that I linked? Yes, basically use an empty, parent everything to it, then animate it so that your camera is near 0,0,0 (world origin). – Sean Novak Oct 23 '20 at 19:02