This instructable can be applied to 3D printing any crown really, but depending on the design of the crown, there might be some difficulties creating the 3D model.
Step 1: Modelling the crown - Part 1
I collect a bunch of reference photos.
I collected a few photos of the crown and realized that the basic antler design is repeated in quarters. This makes it easier to model as I only need to model a quarter of the entire crown and print it out 4 times.
BUT, if the crown's design is unique all-around, then create the vector graphic for the entire crown.
So the way we will get the curvature of the crown is to create an unwrapped, flat version of the crown and we'll do the wrapping in SolidWorks. (Imagine those paper crowns from Burger King)
First measure the circumference of your head where you'd like the crown to sit. This is how long the flatten crown needs to be.
If you are working with a reference photo that you're going to trace, resize the photo so that if unwrapped, it's the length you measured.
In my case, I'm tracing a quarter of the crown, so the size of my trace needs to be a quarter of the length I measured.
I only needed an approximation of the design of Joffrey's crown, so the minor curvature of the reference image isn't a concern to me. I also adjusted the vector artwork a bit to "flatten" the design.