Limit "follow path constraint" motion by rotation speed

#1

Hi,

I’m trying to simulate the trajectory of a vehicle-like object.

I use follow path constraint and this works reasonably well except for sharp corners where the vehicle rotates at infinite speed to be able to follow the path

I would like to constraint the maximum rotation speed, so the object follows the path within certain limitations (ideally max rotation, max acceleration, etc.)

This is the standard result:

Standard

Disabling “Constant Velocity” helps a little bit, but I still don’t see any way to control the rotation speed limit.

ConstantVelocityDisabled

This is what I would like to accomplish, where the object stops in the corner, rotates at a certain speed, and once its properly oriented, it continues its path along the path.

Acceptable

And this is the ideal solution. Since the vehicle can move forward or backward interchangeably, it would find the shortest rotational path and use that one before continuing along the path. I realize this is probably an order of magnitude harder, but who knows, maybe there is a simple and elegant solution to this.

Ideal

I hope someone can help me or point me in the right direction. Thanks!

#2

Fillet the spline vertex, or make a rotation key frames the frames right before and after the turn.

#3

I should have added that this needs to be done not manually ( these examples were done manually,) but the use case requires paths with thousands of sharp corners.

#4

latest max has chamfer spline mod that could save you manual work ?

#5

Yeah, that would solve the infinitely fast rotation, but do you know if there is a way for it to preserve rotation speed the same way it can preserve motion speed and acceleration ?

#6

Adding a spring controller on top of path constraint gives a decent position animation smoothing.

It breaks the rotation though, so add another copy in front of it to look at it with look-at constraint, or use a script that matches rotation to translation direction like these:

http://www.scriptspot.com/forums/3ds-max/general-scripting/automatic-rotation-of-moving-objects-to-match-their-direction