Objects in Array Stretched and Deformed with Curve Modifier

Question

I have a chain object, and I have a curve it follows. I got it to work for following curve, but chain object are not circles but both parts are more like stretched circles (ovals).

Object I made with two toruses one rotated 90 degrees and then joined them together. I tried single torus too, but same issue persists, on a curve it just looks like a stretched oval.

What is the issue?

Answer 1

The curve modifier distorts the objects, that is the intended behavior. If you want an undeformed array use either by Instancing (Duplifaces before 2.8*) or a particle system instead.

Add your Array+Curve modifier stack to a simple plane mesh instead.

Create a new plane mesh, parent one single chain link to it and activate Object Properties > Instancing > Faces (Duplifaces pre 2.8*)on the plane's object properties.

Then add the Array modifier, use an empty object rotated $90º$ to introduce rotation to each link. Activate the Object Offset option and pick the empty.

Adjust spacing and settings as desired, and then add the curve modifier exclusively to the plane object alone.

Alternatively use a particle system instead of Instancing > Faces feature with one particle per face if you wish to hide the original link independently. Manually adjust particle count to match the number of arrayed links.

Answer 2

For modern versions of Blender with Geometry Nodes available, a friendlier approach can be used.

1. Add a Geometry Nodes modifier to your bezier curve.
2. Use a Curve to Points node set to Length, and adjust the Length as desired.
3. After that use an Instance on Points node
4. Add whatever geometry you like to the Instance socket. In the illustrated case I constructed a torus (from a curve circle and a Curve to Mesh node, but you can use any bespoke object instead)
5. To rotate every other instance you can use a Rotate Instances node
6. Under the Selection socket connect an Index node to identify which instances to rotate
7. Between the to add a Math node set to Modulo of $2$, to only select every other instance