CGTalk - Constant Interpolation Doesn't Always Work

View Full Version : Constant Interpolation Doesn't Always Work

bcbarnes

01-15-2006, 07:21 PM

Searched through previous posts but didn't see any resolution to this problem. If I set the key type to "constant" in the keyframe controls, and am in full body mode, then set some keys, I can see in the FCurves that all the keys have constant interpolation. Unfortunately, the character doesn't behave that way when I scrub the timeline. Specifically, most joints seem to work fine, but the hips and ankles seem to react as if I had linear interpolation set.

I've included an FBX file that demonstrates the problem. Keys at frames 0, 30, 60 rotate the shoulder in constant interp mode, and that works fine. Keys at 60, 90, and 120 rotate the hips, and that is also in constant interp, but it doesnt "pop" in when it should, it slowly slides up to the keyframe, and then "pops".

I have found that I can "fix" the ankles by setting the reach(r) to 100%, but I can't figure out how to fix the hips.

Brian.

bcbarnes

01-16-2006, 10:59 AM

Got the solution from "bclark" over at the alias user forum, and thought I'd pass it along.

You have to select all the IK effectors, and all the FK effectors, and in the properties window, set the "Quaternion Rot" option to un-checked. Don't really know what this does, but it fixes the problem.

Brian.

intovidfilm2

01-23-2006, 02:23 AM

This has been driving me insane.

Think it has something to do with the Ik/Fk integration.

Haven't been able to figure out how to select between viewing FK or IK curves.

Per this post:
http://forums.cgsociety.org/showthread.php?t=224382&highlight=constant+tangents

What if you set the keframe type to Constant before you key,then key in Full Body mode.Or drag select the keys in the timeline and right click> Interpolation>Constant.

I tried the timeline selection range, and it works.(Highly unintuitive, very annoying, compared to working in native 3d app, as I'm sure you realize this makes for some seriously inefficient workflow.)

If anyone knows another method, or how to view fk/ik curves independently , please chip in. This is extremely annoying.

Would really like to understand what is going on here, perhaps once understanding it will be just easy workflow. For pose to pose, this was, and still is a headache.

Besides just doing this stuff that appears to work, I would like to understand the workings behind it, why it might be wrong,ghost keys or whatever.

CGTalk Moderation

01-23-2006, 02:23 AM

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.