General Category > Ongoing Anim8or Development
IK tool
nemyax:
--- Quote from: johnar on October 06, 2016, 06:10:33 am ---a fluent method of character animation would require being easilly able to flick back and forth between IK and FK.
--- End quote ---
This is commonly done by making IK strength a separate animation track where you can set keys in the range 0.0 (full FK) to 1.0 (full IK). In this case, rotation keys are ignored at full IK, and they get more influence as IK strength decreases.
Of course, this requires that IK be based on a real-time solver instead of a system for auto-setting rotation keys as in the current Anim8or.
Steve:
johnar: I agree that all those trackballs is too cluttered. Showing just the last clicked-on bone could be a nice solution. I'll experiment.
I also plan to try enabling IK with the Bone Rotate tool: with IK visible, you'll be able to click-drag an IK handle, or click to select and then use the IK widget. In effect IK and FK would be the same tool. The only catch is that I haven't worked out how to move the whole figure like you can now in the IK tool.
I've also looked at 3D Studio which only shows 1 trackball even when you select multiple bones, but when you rotate it the bones rotate is odd ways, not how you'd expect with a skeleton system. But it doesn't show multiple trackballs, at least I haven't been able to make it do that.
I forgot to add: "I also notice the z axis often wont rotate all the way to its limit." When you rotate along one axis it can also change the others. The X can affect all three, the Z can also change X, but Y is independent. This is because of the order that the rotations are used when building the final (quaternion) orientation: First rotate X, then rotate Z in the resulting orientation after X has been applied, then Y after both X and Z. (It's mathematically impossible to do them simultaneously!)
So when you rotate around the Z axis and the X angle is also changing, when either the X or Z value hits a limit the rotation stops.
Note that when yo display the axis as arcs (hot key-X) the three axes are not always at right angles. unlike the trackball whose axes are. This is because the trackball rotates uses the final orientation as it's basis, thus avoiding the gimbal lock'
nemyax: I'm not sure what it would mean to have half IK and half FK. Do you move the effector half-way to the goal?
johnar:
steve
Ok. Good one. Understood, and interesting. Thanks for that. Cheers. :)
nemyax
Thanks for the comparison. :)
nemyax:
--- Quote from: Steve on October 06, 2016, 08:13:16 pm ---nemyax: I'm not sure what it would mean to have half IK and half FK. Do you move the effector half-way to the goal?
--- End quote ---
I mean IK animation and FK animation are independent from each other. Which one kicks in depends on which is currently enabled, and the on/off state of IK can be animated.
nemyax:
Steve
Here's an example of this in action (Maya):
Note how the bones are animated with both FK and IK and you can switch between the two. While one is active, a ghost animation of the other is displayed (this is optional).
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version