Is there a way to Wrap around an ellipsoid? or to code to Wrap around an ellipsoid?

Alex_Laws

I've seen the Wrap tool used on cylinders, and now cones. On cylinders, i know there's a center point that the wrapped face can rotate around. On a cone, it's probably the same, following the same point but rotated on an angle before revolving around the center point.

Is there a mathematical way to do the same on an ellipsoid? or a sphere?

The first problems i would run into when thinking of this (i'm not a good mathematician) is the computer power needed when calculating how much to bend into the point like on a cone. On a cone, you bend inwards linearly, while on an ellipsoid it's non linear.

HOWEVER, i'm 90% it could be fully mathematically correct.

Another problem is that if it were to be a feature/featurescript it would probably be really intensive to run, most likely with slight distortion.

Again, i'm not an amazing mathematician, so I don't know how this would be made.

Alex_Laws

Noting my ideas for possible featurescripts for reference for others or for myself:

not sure if these will work

1. Wrap using a dummy cylinderto make some surfaces, then unlinearly scale them.
   1. Problem: solves the axis of curvature in one direction, but not the other.
   2. Solution: Find a way to bend surfaces once they have been wrapped

Alex_Laws

1c. Problem 2: There is no known way to Bend surfaces that have been made.

S1mon

Other CAD tools have much more powerful ways to wrap 2D objects onto 3D. It also depends a lot on how you want things to distort. The conic wrapping that's been added recently treats the 2D object as something to literally wrap as though it was a flat (but flexible) sticker. Other people have wished for something which is more like flowing or deforming.

Here's Plasticity's "deform" tool which is similar to Rhino's "flow". In this case first you "unwrap" the conical surface (which was previously split) which creates a flat reference rectangle. Then the flat orthogonal pattern of cylinders was created on top of the rectangle , and "deformed" back. You'll notice that the cylinders are distorted by the "deform" tool. The top row is closer to being approximately round, but the bottom row is more elliptical. The bases are also smaller and they all grow as they protrude from the cone.

Rhino's version has history (unlike Plasticity):

https://www.youtube.com/watch?v=DFvPl2nW0K0

jelte_steur814

I think a way of approaching this would be to use the inverse of onshapes 'flatten surfaces' tool. it internally does some FEM to minimise strain. the inverse of the 'transform/deform' to flatten a surface, would be the wrap 'transform/deform' to be applied…

Even though the flatten surfaces feels very much like a feature, it's an analysis tool and not accessible through featurescript i'm afraid. If it would be, that would allow this to be coded up into a custom feature…

Flatten surfaces explanation:

https://www.youtube.com/watch?v=_e9inPNNZoI.