# How to convert physics animation to a curve/path?

Ok. I have a ball at the very top and a long curved tube leading down and I want to turn the ball's physics animation into a follow path animation. In order to do that I need to somehow make a path out of all location points in which the ball was during its fall down the tube. But I don't know how to do it...

• You are wrong. Locations points I'm speaking about are the ones in physics animation of the ball.
– Rig
Commented Dec 23, 2018 at 23:24
• Why do you want to convert the physics animation though? Why not keep it?
– Sava
Commented Dec 23, 2018 at 23:30
• In order to make my camera follow that path. And because knowing how to do such things could be useful in the future to my other projects.
– Rig
Commented Dec 23, 2018 at 23:34
• As I said below, I don't think it is possible. But, why don't you make the ball as a camera, or make a camera follow the ball instead?
– Sava
Commented Dec 23, 2018 at 23:38
• The ball is rotating a lot - I'm not sure how to handle camera's rotation so it would be inside the tube and point at the ball all the time. I want to avoid extra work in setting its angle right. Converting the animation to a curve would be fast. Also I could just save that curve for later, put it together with other curves and easily compare if I would need to in the future. It is much easier to store curves than entire animations.
– Rig
Commented Dec 23, 2018 at 23:48

One method of converting a motion into a path is detailed in How to add trailing light effect to finger tips - by adding a particle system to drop particles as a vertex moves through space and then running a script to convert that particle system into a path. I also created an add-on as part of this answer to make the process easier.

Once you've installed and enabled the add-on and you have your trail of particles (disable gravity and interactions from your particle system and have it emit a single particle for each frame of the animation) you simply execute the Particles to Path function (press Space (Blender 2.79) or F3 (Blender 2.8) and start typing the name) :

This should then generate the required path which you can use for your Follow Path constraint.

You can easily create a path by using a curve, and set it in the centre of the tube. Then set the ball to follow that curve.

• It would be time consuming and really inaccurate since the tube is long and twisted and the ball is bouncing a lot. I want to take out part of physics animation of the ball and turn it into a curve.
– Rig
Commented Dec 23, 2018 at 23:28
• I don't think that's possible.
– Sava
Commented Dec 23, 2018 at 23:29
• It should be. All locations of the ball during the fall combined should be easy to convert into a curve. And getting them out of the animation shouldn't be hard. At least I see no problem in that unless it wasn't ever implemented.
– Rig
Commented Dec 23, 2018 at 23:42