Skeletal animations require position, rotation and scale on every key, and instead they should be independent of each other

[kdrnic]

Currently skeletal animation keys as passed to THREE.Animation constructor are like this:

{
   pos: [ , , ],
   rot: [ , , , ],
   scl: [ , , ],
   time: 
};

the problem is that it is required that both pos, rot and scl fields be present.
This is problematic depending on the animation.
Suppose we have a bone animated like this:
Frame 1) Set rotation, set position
Frame 2) Interpolate rotation, interpolate position
Frame 3) Set rotation, interpolate position
Frame 5) Interpolate rotation, interpolate position
Frame 6) Interpolate rotation, set position
Frame 7) Interpolate rotation, interpolate position
Frame 8) Set rotation, interpolate position
etc. etc.
it is impossible to pass such animation to three, because some keys will have either rotation or position set and expect the other to be interpolated from values defined in a previous key.

If a key is passed without the pos array, it will give errors of "Cannot read property '0' of undefined" in three.js:29612.

If a key is passed without the rot array, it will give errors of "Cannot read property 'x' of undefined" in three.js:728.

This has become quite annoying as I am trying to correctly implement a loader for a format that allows keyframes to have only position or only rotation set.

[mrdoob]

So the workaround is to create interpolated values in the data or zeroed values?

[makc]

to create interpolated values

you would have a whole layer of code on top of this to make it work. people will want to export curves. makes sense from the file size point of view.

[mrdoob]

Yes. I just wanted to double-check that I understood the problem.

[Dynasty9]

With the current setup is is possible to animate the upper half with one animation and the lower with another?

[kdrnic]

@mrdoob wouldn't this be more fit as an Improvement rather than a suggestion (I am talking about the label)?

[mrdoob]

😊

[kdrnic]

kdrnic/three-mm3d#1 was closed by making a function applied to the data before it is used to construct THREE.Animation. It checks for keys lacking pos or rot, looks for the closest previous key and closest next key not lacking, and interpolates linearly.

[donmccurdy]

The THREE.Animation class no longer exists, and as far as I know this case works correctly with the new animation system. Please reopen if this is still reproducible.