1
$\begingroup$

I am dribbling a soccer ball using child of constraint. In the image I would like to keyframe the ball where the arrow in drawn but when I try to keyframe it it still follows the child path, How do I fix this?

enter image description here

$\endgroup$
  • $\begingroup$ I see you have the 'Influence' slider keyframed at 1.00. Is it also keyframed down to zero somewhere along the timeline? If so what happens? When you say it's following the 'child path', what path is that? Experience has taught me it's best to duplicate the ball, remove all constraints, animation, and parentage, and switch to that. There's no complications then. You can still switch back to the other if needed, or to any other duplicate if need be. $\endgroup$ – Edgel3D Aug 28 at 12:08
  • $\begingroup$ when the influence is 0 the ball either stays in its original location or at keyframe 80 if i change influence to 0 it goes back to its original location. The child path is the left foot. regarding duplication, lets say I duplicate, what do I do then? $\endgroup$ – Kamran Ali Aug 28 at 14:27
  • $\begingroup$ It will need a step by step explanation. I'll put an answer together. $\endgroup$ – Edgel3D Aug 29 at 2:46
0
$\begingroup$

Whilst your project has the ball constrained as a Child of' the parent character (or foot) I've instead placed physics properties on the ball for the initial bounce and returned to physics when it enters the goal square.
Exactly the same process applies though and this will always work - give you a completely 'free-from-constraint' ball with which to do as you wish.

The video (above) is what happened when kicked with the physics in play and for whatever reason would not behave as needed.

The second (below) when employing a duplicate to bypass the physics altogether..

The procedure -

When kicked, at the frame the foot comes into contact with the ball, stop the animation and duplicate the ball.

Immediately remove the copy's constraints, physics, animation, parentage, everything, so you end up with a free and unconstrained mesh.

Keyframe the copy's location and rotation.

In the Outliner, keyframe the original ball to invisible and the copy to visible.

Go back to frame 1 and keyframe the copy's loc/rot again.

Also reverse the visual switching in the outliner and keyframe that. (the original is to be seen at frame 1, the copy to be invisible)

Animate the copy and send it into the goal square. (emulate a bounce or two?)

-===============-

Whilst unnecessary, for demo purposes here, the original (physics) ball is switched back as the copy crosses the goal threshold.

Similarly in your project, you can also switch back to the child-ball at anytime.

Switching back - At the frame required...

Move the player-character so the two balls are at the same location. (or close) Use SH-S to set the 3D cursor to the selected duplicate, then select the original ball and send it to the 3D cursor's location. (SH-S again)

This will place both at precisely the same location. From there it's a simple matter to rotate the child-ball in all 3 axis' until they're aligned again. I've found it easier to use wireframe mode and "Normal" orientation for this. Always be in ORTHO view.

-================-

When the balls are textured you have to ensure this is matched at the switch-back frame also -

An easy way to do this is -

Temporarily remove the original ball's smoothing and texture. Reassign one face to a bright colour before duplicating. At the switch-back frame rotate both balls so their mis-coloured faces match up.

-===============-

Switching can take place between the two balls as often as needed, all without fear of some constraint's apron strings mucking you around.

The monkey video below has been freely switched back and forth between physics and animation several times, plus throwing in a path constraint for good measure, all without a single glitch. It's a basic workaround but it always works.

Monkey Blend file is available if you want that.

$\endgroup$
  • $\begingroup$ Thanks I will try this, what about dribbling the ball? How do I make it smoother by using child of constraint? $\endgroup$ – Kamran Ali Aug 30 at 17:34
  • $\begingroup$ If you're asking how to smooth the dribbling with parentage, I've never tried it. If you're asking for a smooth transition to the duplicate when the original is moving, then at the switch-over frame you have to start the animated ball off instantly at the same speed as the original. (i.e. experiment) Don't set the keyframes to 'Linear' or you'll lose the adjustment handles in the Graph editor. Instead use the launch (1st) handle to start it off at speed, not accelerate gradually. If you're inexperienced I guess I can throw a video together, show how it's done. $\endgroup$ – Edgel3D Aug 31 at 1:38
  • $\begingroup$ Please show a video as it will help translate everything youve said. Would that be ok? $\endgroup$ – Kamran Ali Sep 1 at 20:19
  • $\begingroup$ OK, will do, give me a few days, I'm laid up with a bung leg at the mo... Maybe I should apply a modifier or two on it. $\endgroup$ – Edgel3D Sep 2 at 4:04
  • $\begingroup$ Thanks boss. Will wait for it. $\endgroup$ – Kamran Ali Sep 2 at 17:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.