if you apply the polygon collider to a sprite, Unity has a really nice system of letting you edit the polygon in the editor, by clicking and dragging nodes and clicking to delete them etc. But the actual sprite is an image and completely independent from the collider. I wonder if there is a tool in the asset store with which I could create (rather than import) a “polygon sprite”, so that editing the sprite and its polygon collider is the same thing. This would be fantastic for prototyping. I am looking for a simple 2D version of what ProBuilder already does for 3D.
A similarly useful tool would be a spline sprite: Editing the spline would automatically edit its collider, which would be great for prototyping racing games etc. Is there such a thing?
Ragespline might fit what you’re after. It’s not quite as straightforward as creating polys in a 3D DCC (rather than just freely drawing shapes, you drop in spline-based prefab shapes and edit those).
It hasn’t been updated for quite some time, but if you just want it for chucking things together it may fill a hole.
There are some other in-editor editors, though I think most interest has been around solid modelling, and I’ve not really used any of them. Have a look under Editor Extensions/Modelling.