unity3d - Unity 4.5 Mesh Collider Not Interacting with Circle or Box Collider 2D -

unity3d - Unity 4.5 Mesh Collider Not Interacting with Circle or Box Collider 2D -

i new unity , working on 2d game. currently, having problem getting 2 colliders interact when 1 of them mesh collider , other box or circle collider. working unity sample assets 2d character interact mesh terrain. when "played" game, circle collider attached legs of character falling through mesh terrain. have simplified problem , created 2 cubes:

one cube upload , maintain 2d box collider , add together stiff body to the sec cube delete 2d box collider , add together mesh collider

i place sec cube under first cube , nail "play". top cube falls through bottom box. when replace bottom cube's mesh collider box collider , nail "play" correctly collides , stops on box. i'm guessing i'm making same error in simplified illustration in more complicated 2d character scenario. have suggestions of doing wrong? have tried making mesh collider convex (although believe should necessary between 2 mesh colliders?). have ensured z position same layers of 2 objects.

you cannot collide 3d object against 2d.

void oncollisionenter2d(collision2d coll) { // code here clueless 3d. }

api reference.

sent when incoming collider makes contact object's collider (2d physics only).

you cheat little. before unity had 2d colliders people create lean box collider3d, in case should work.

unity3d 2d unity3d-2dtools