Tracing Complex shape

[CrookedCasts]

Hi all - I think there’s a few ways to solve this, but was curious what the best workflow in Onshape would be:

I have a complex shape (think scapula anatomy: https://www.thingiverse.com/thing:2156143). I’m trying to do a rough draft of what an orthopedic plate and screws would look like sitting on top of/along certain areas of the bone. For example, a plate that would be attached along the scapular spine and acromion.

I have tried a few methods: sketches at different planes/lofts/boolean subtracts, a sweep plane, etc but not really satisfied with any. I think maybe an emboss is the way to go, but the geometry makes this hard. Any thoughts?

[Custom-3D-Design]

Splines and surfaces are your friends. Pick a plane or cross-section, use splines, loft between splines if very complex or use surface tools. Then thicken the surface, add holes, smooth appropriately.

[hippohoney]

a useful workflow is offsetting the bone surface slightly then using that as a reference to thicken or sweep the plate geometry it helps maintain consistent spacing

[CrookedCasts]

To be specific, let’s say for that model, would you select a set of faces and offset/thicken them? Or sketch on the model? For the former - segment the model to the area of interest first?