Why don''t you just check if the mesh is on the right side of the circle, (you can use a dot product for this I''m pretty sure) and then check for distance (radius). That should get you what you need. It''s just a 2-step process.

Here''s what you need to do as an exact formula:

Let v = the vector that represents the direction that you''re facing, or the middle of your swing.

Let u = the vector from the point of swing to the point you want to test.

if u dot v is > 0, then it is on the side of the circle representing your swing that you want.

THEN

if the distance between your centre of swing, and the point you are testing is less than the radius of your swing, then that point is getting hit.

There you go, that''s what you need to know. You might want to look up a good book about linear algebra and matrices. I''d suggest "Linear Algebra and its Applications, Third Edition" by Davic C. Lay.

Any questions, just write back.

I almost forgot to say this. If the bounding boxes don''t intersect, then they aren''t going to hit at all. Also, if the bounding boxes interesct, then you''d probably want to test all of the vertices to make it very accurate. You could probably get by checking only every second vertex assuming that your model is fairly detailed, and not spiky.