SpriteCollection Editor Polygon Collider questions

[Intrawebs]

I can't seem to find documentation on what these three items below are and when/why I should use them?

Collider Type = none, front & back, font, back
Convex = true/false
SmoothSpehereCollision = true/false


I'm creating a top down arena game would like to use polygon colliders for my sprites, which is fine, just want to know if I should be messing with these options above.

[unikronsoftware]

If you use 3d colliders, it creates no caps by default. Front / back / front & back adds these caps to 3D colliders.
Convex ticks the convex box on unity 3d colliders, and likewise for smooth sphere collisions.