- Home /
Concave collision issue with 2D game
Hi to all. I don't understand why if i use a concave collider with my 2D game the 2D objects cross the planes and crossing each others as if there were no collider. Instead, they don't do this with 3D objects such as Boxes... If i use a convex collider they works without problem with all others colliders... (See the image below) 
Only mesh colliders marked as convex can collide with each other.
Answer by NowhereStudios · Oct 13, 2012 at 10:18 PM
Concave Meshes simply can't only collide with other concave meshes, so if you need something like this, then:
You must split them to convex collider parts
Create an concave game object. dont create any colliders to it.
Add convex part game objects in to your concave gameobject.
Add mesh collider to your convex meshes and mark them as convex.
Remove your convex gameobjects MeshRenderer and MeshFilter components.
Goodluck :)
Answer by Daniele92 · Oct 15, 2012 at 08:44 PM
Thanks for response.. And isn't there an automatic solution to make concave vs concave collision? becaus i'd like to use ragespline 2d programmatically to make complex shapes..
Answer by UGTools · Oct 18, 2012 at 01:23 PM
There's a solution to automate this available at the Asset Store and that may help you: link
Another workaround is using compound colliders, basically what NowhereStudios describes. You can get documentation about this here (search for "compound colliders").
Your answer