Recommended animation cycle lengths and key frames

General Discussion
1

I may of missed it but cant seem to find anything on rule of thumb for animation cycle lengths and recommended number of keyframes. Everything on search is basic generalizations.

I figured 24 FPS for frame rate is normal so should the cycle be completed in 2 seconds or 4seconds on average with 8 keyframes for example?

Any links or input is welcome.

Thanks.

2

I don’t know of anything specific to reference, sorry.

From experience, I find I use 8 key frames for a walk cycle, which last 1 second or so… I find i am always playing with the animation speed in engine to get my animations running correctly … while animating i find i leave an arbitrary amount between keyframes, some days its 10, others 20, so speed tweaking is always needed.

My latest line of thought is exporting only keyframes, and slowing down the animation speed, letting the engine take care of tweening. The downside is, for now, that means all interpolation will be linear, you can work around this by adding some extra key frames. I feel using this method of only exporting keyframes:
a) reduces load on the engine (wild assumption); and
b) makes for smaller file size (i have it in my head the ogre exporter exports every single animation frame, which makes file size unnecessarily bloated… this could be wrong, and my not be the case with blender importer or XBuf, I don’t research =/

3

(sorry to jack your thread here) toucher, if you have a loop that start and ends on identical frames (e.g. walk) do you export with the last frame == first, or is perhaps export the 2nd to last so there is some interpolation between the 2? Because all my walk cycles look like they have a tiny hitch when they loop - as though it plays that frame twice without moving.

4

for an animation that is 4 keyframes long …

key frame 1 goes at frame 0;
key frame 2 goes at frame 10;
key frame 3 goes at frame 20;
key frame 4 goes at frame 30;

then (when the animation is finished):

a copy of key frame 4 goes at frame -10;
a copy of key frame 1 goes at frame 40;

then:

export frames 0 - 39;

5

Thanks for the response. Do you lay the root bone parallel to the ground or perpendicular? I’m seeing parallel in modeling examples but the jmonkey tutorial shows it as perpendicular to the ground. Both examples do have the origin at 0 though.

6

perpendicular. In the past, if the root bone was not at 0,0,0 there were issues, I don’t think this is the case anymore, the last few armatures I have used did not have the root bone at 0,0,0 and have worked fine.