I do not know anything about 3D printing, let me know if another place might be more appropriate for this post.
My friend about three months ago was in a catastrophic motorcycle accident. He was hit by a texting F150 truck driver. He lost his leg, an eye and has had pretty much full body reconstruction, including jaw and face. He was wondering if he could 3D scan in the helmet he was wearing with all the first responders/doctors (who helped save him that night) signatures then give each one a copy to thank them. He is in Ontario/Brampton area. He can pay for it.
Picture is not of actual helmet. Being sent down from up north right now.
I should add, that scanning the transparent face/eye guard there will prove challenging, you might want to cover whatever is left of that with tape to help scanning…
Perhaps if you tape transparent parts, only from the inside, then perhaps you might be able to better capture the cracks themselves…
Just my thoughts on it…
Some dulling spray will give you decent enough coverage for a laser scanner to pick up the shape. Helmets tend to have large featureless areas that make optical based scanners struggle and photogrammetry not feasible. A good engineering level scanner will be just fine.
I once ran out of contrast spray on a job, ended up using Tinactin. No shit, it produces a very scannable white matte surface.