Releasing an object from the hand

As I have learnt, the hand picks an object

  1. using the child-of constraint, setting the influence to 1 & applying a keyframe. Then in the previous frame, the influence is set to 0, click ‘set inverse’ and apply keyframe.

But in releasing the object at a specific frame,
2) go to the next frame & set influence to 0. The object jumps elsewhere but can’t be brought back by ‘Set inverse’.
So what’s the simplest way to release please?

Take the Dynamic Parent Addon.

Tutorial is in first post.

Maybe this is too obvious, but you can keyframe the new location.

Sorry, New Visitor. What’s the Dynamic Parent about?
Is it applicable to my query?

Sorry, I don’t follow.
Can you please explain more?

Go to the next frame.
With the released object selected, press “i” to insert a keyframe and choose location.

I am sending a screenshot of a man holding a cone and wishing to release (throw) it in frame 20. Note the influence is 1. If set to 0, the cone jumps to another location.

Sorry, images got superposed. Don’t know why.
Will try again. [Can’t send Blend file - too large.)

Right, and when it goes back to its original (un-influenced position), move it to the influenced one again, manually, and set a keyframe…

Thanks for that. I did try manually - something I wanted to avoid.
Manually, it is not easy to get it back in the exact position it was before the Influence was set from 1 to 0. I wonder why the ‘set inverse’ doesn’t work with Release but with picking the object.

To get the position manually, go into pose mode and select the bone. It will tell you the exact offset from the origin to use.

I am sending the screenshot again. The man holds the object (cone) in frame 19 (influence=1) and wants to release it at frame 20 where the influence is still 1. But the moment it is set to 0, the cone jumps elsewhere. It would have great if it could be brought non-manually.

Before disabling the constraint, select the object and ctrl-a apply visual transform. Then mute the constraint and keyframe (constraint + transform). This will transform the object to the proper constrained orientation but without the constraint.

Because this involves a frame delay, this has the potential to look twitchy. If you know how you want it to move, you’ll actually want to temporarily apply a visual to the last frame at which the constraint is active, get a proper f-curve going, register the next frame, then go back and undo the visual you registered.

(This should work with just registering visual transforms instead of applying them, but for some reason it doesn’t work with all constraints, so I apply the visual transform and register it manually like this instead.)

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I would treat this as two perfectly-timed animation sequences. First, the ball is parented to the hand with an influence of 1.0. At the moment of release, the move is done by keyframing. First, the ball is keyframed at its present position (so that it doesn’t move), and the influence is keyframed to become zero (instantly). The remainder of the ball’s path is simply more keyframing. Be sure that the animation-path governing the influence does not ‘lead out’ to zero.

Your solution would be okay if the offset was known but Pose Mode only applies to Meshes.
The moment you select the object, we are switched into Object Mode and restoring the precise orientation of the object becomes a bit of guesswork.

Thanks, Bandages. I feel you are on the right track and your scheme is elegant to start with but I got stuck again.
To be precise, (looking at the screenshot) I selected the object (cone) & set a visual transform [what a grand name] at frame 20 where the influence=1. The cone promptly moved to its original location on the table. Now I set the influence to 0, whereupon the cone moved to its old position in the hand. Excellent.

I now wanted to move the cone (relieved of the constraining hand) along some arbitrary path. But the moment to moved to the next frame (by R arrow key), the cone jumped back to its old position on the table ! Most disappointing.
Perhaps I should undo the Visual but how??

Did you keyframe just before changing frames? Both position and constraint influence?

There is no guesswork, open Pose Mode for the armature and click on the bone, in the Items menu on the right of the 3D View (the “N” menu), if you click the bone it will tell you how much that bone has moved from its rest pose. That offset is exactly how much that “Influence 1” slider was affecting the other mesh.

I believe you should follow Edsa because I like his approach better anyway, but you should definitely know that you can get the transform of a bone (how much it is influencing)

The operation of the Add-on looks great - once it is set up.
I’ll wait for the 2.8 version. Thanks for proposing the Add-on.
It may prove to be popular.