polygon bug?

vyh77

Hi,

Either there is a bug, or I still don't understand the coordinate system.

I created a triangle like this:

local triangle = b2.PolygonShape.new() triangle:set( 0, -20, -5, -10 5, -10, )

which is in my opinion convex and CCW. But I got error "Polygon should be convex and should have a CCW winding order."

When creating the polygon CW, works fine without errors:

local triangle = b2.PolygonShape.new() triangle:set( 0, -20, 5, -10, -5, -10 )

tkhnoman

This is a very well known limitation for box2d.
So you don't need to treat this as bug.

vyh77

ok, thanks for the answer! Maybe it's a good idea to explain this limitation of box2d on Gidero's documentation: http://docs.giderosmobile.com/reference/physics/b2PolygonShape/set

It would help newbies like me.