Thanks for the answer, I have another question, seeing your previous work on custom keyframe animations, so I used your custom curves for a test experiment, but the expected behavior of it was puzzling, the first is that it is moving in the opposite direction, and the second is that the position of its movement is not the 30 I gave Use keyframes to customize interpolation errors - Questions - three.js forum (threejs.org)
You can see the difference in the case by quickly commenting on this line of code
