Why do animations along a path cause extremely drastic changes in rotation?

(PixelLove3D) #1

The position follows the path smoothly, but literally between the first and second frame of a spider with the “follow path” constraint on the master bone, there’s this extremely sharp rotation that messes up the rotation of the spider for the rest of its path animation. These sudden snaps occur several times throughout the animation and there’s no reason for them. The curve is fairly smooth and there’s lots of vertices in the curve to interpolate smooth movement. I did notice that for no reason whatsoever, tiny changes in the positions of the vertices near the spider either through the hooks or in edit mode tend to drastically change the rotation of the spider.
How can this be fixed for all points along the path? The only thing I’ve noticed is that there’s this curve property called “twisting” and I set the smooth really high. That fixed the sharp rotation between the first and second frame, but not for any of the other frames.


Drastic Turn Example.blend (10.2 MB)

(Jason van Gumster) #2

Moved from “Artwork > Animations” to “Support > Animation and Rigging”

(erickBlender) #3

Checking your .blend i have noticed few things that might cause unwanted effect on your animation.

First when animating with many different objects, it is advised to make every object’s origin to be in the same place, and make sure that all axes are pointed on the same direction before parenting.

Second: when using curve you know that when you go to edit and do ctrl+t tilt the normals?

For me those the things i will fix first and see how things are going.

(PixelLove3D) #4

Okay, the tilt definitely helps. It doesn’t fix all the wrong rotations but it helps, thank you.

(sundialsvc4) #5

I build a separate library-file of every object that’s going to appear – sometimes using a bunch of Scenes so that I don’t literally have too-many files – and each object is built with an origin at (0,0,0) in the center of the screen with no rotation or scaling. If the object is going to ordinarily move around a certain point in its geometry, that point is designated as its local origin.

Every subsequent use of that object in any scene is linked to that one asset (from a separate blend-file).

Sometimes the library-asset files contain a test Scene in which the objects are shown moving around. (This Scene is linked to the object-source scene(s) in the same way that other, external, blend-files would link to them.)

Each object is constructed to-scale, with a certain agreed-upon relationship between Blender Units and real-world units of measure. (Every reference photo has one or more tape-measures in it.) The object is thus of its correct, real-world size when no scaling is applied to it.