Animating a joint relative to position of any underlying pose/additive animation

[Thaumaturge]

@LifeLand

In the part you quoted, i was trying to explain why pure half-body animation wouldn’t solve my problem…

Ah, fair enough–I thought that you might have been talking about half-body animation, but I wasn’t sure, and it seemed better to check!

@LifeLand

The character’s running animation needs to affect the upper body, because it doesnt look right if they arent throwing their weight around and maintaining ballance while they run.

Sure, but can you not perhaps incorporate that into your “aiming” animations–making them no longer single-frame, of course, but allowing them to incorporate reactions to movement?

(This would of course incur one animation per movement state, but should work well, I imagine.)

@LifeLand

What would be more useful in my situation is additive blending, so like
8(main animation) + 2(animation layer) = 10
Or 8 + -2 = 6

I may be mistaken, but I’m not sure that this would work–at least, not without having your animation layer incorporate some adjustment for the motion of the main animation.

For example, consider the following stick-figure:

      O
      |-----
      |
      |

Now, let’s say that the main animation has this figure bend backwards:

   O  /
    \/
     \
      |

Because of the parent-child relationship between “back” and “arm”, the arm is lifted by the motion of the back–without the arm having any animation of its own, mind!

To counter this, we’d presumably want to animate the “arm” downwards. But if that backwards bend isn’t present throughout the main animation, then when it’s not bending backwards the downwards animation of the “arm” would result in the arm pointing downwards…

What you really want, if not half-body animation, is arguably some form of inverse kinematics, in which you specify the object-relative direction for the arms and then do the reverse calculations to determine the required bone-positions for those arms…

[edit]
If you do decide to look into inverse kinematics, then perhaps take a look at this thread:

Simple Inverse Kinematics Solver

I created a simple IK solver for Panda3D. It’s pure python and supports hinge constraints and ball constraints. The implementation is based on CCD (Cyclic Coordinate Descent), which creates relatively smooth motion. [IK-2021-03-08_22.14.25] [CCDIK-2020-12-29_17.31.24]