Creating UV Map from Specific Section Of Model Without Certain Deformities

Question

If I have a hollowed out hemisphere-like object with a bunch of holes in it (think hollowed out bowling ball or something), is there a simple way to get a UV map of only the outer side EXCLUDING the holes?

In my mind, thinking of something along the lines of shrink wrapping something and being left with the plastic I guess? Specifically, this is for exporting the UV map as a guide for a sewing project, so the goal is to have the surface of the object in a flat format without holes.

I'm relatively new so I'm not sure how I would go about something like this, thanks for any suggestions!

Answer 1

When mapping a curved surface (such as a hemisphere) to a UV Map (always flat) some distortion is inevitable. For this example I've created a hemisphere similar to what you've described, with the previous UV mapping deleted (Object Data Properties > UV Maps > - Remove UV Map). Seams (UV > Mark Seam) have been marked around the holes, and all faces except in the holes are selected. The view in the 3D Viewport is Top Orthographic.

Above a UV map of just the selected faces (the hemisphere, sans holes) has been created, exactly as seen in the 3D Viewport (UV > Project from View). Because the View is orthographic, distortion is minimized for the faces flatest to the view, and greater for those as their angle from the view increases.

There are several ways to reduce distortion on the outer faces of the hemisphere. Above, outer edges of the hemisphere's UV map have been selected and scaled (hotkey S) by hand. The holes have been UV unwrapped by inverting the selection in the 3D Viewport (selecting only the holes), then UV > Unwrap, then scaling down.

Whether or not this would be suitable for a sewing guide (probably not), or how to use Blender to make a sewing guide, is somewhat outside the remit of the Blender Stack Exchange (which covers questions about using Blender, but not sewing).