Man, these types of programs really make me nostalgic and brings me back to when I was a child. I was obsessed with 3d software like blender and sketchup.
https://web.archive.org/web/20180322042858/http://www.stmuc....
TLDR; Wall of Text: Blender 3D is awesome! (Godot + Blender = Even Better.)
My favorite early learning app was wings 3d, really fantastic modeling flow and creates clean messages by default
(1) http://www.povray.org/news/moray-announcement.phphttp://www....
I was going to model a lot of pieces and make a game or something, but I spent so much time on the head that I gave up after that.