Previous | Next --- Slide 71 of 79
Back to Lecture Thumbnails
dchen2

There is a way to solve this with cross products, but I was wondering if it is more efficient to use matrices: assuming the triangle is nondegenerate, we can consider the basis {P1 - P0, P2 - P0} and check if the coordinates of q under this basis are positive and have sum less than 1/2.

bobzhangyc

Can i represent each edge as a vector and do some vector calculation to check if a block is in a triangle?

dab

How often do we want to do this instead of using Barycentric coordinates?

anag

Would this involve calculating the angle between the vector from Pi to q and the vector from Pi to Pj and checking its sign?

tcarey

Is this the same method we use to sample points for interpolated color and uv coordinates?

Oh_skr

Could we compare the sum of the area of triangles P0P1q, P0P2q, P1P2q against the area of the triangle P0P1P2? These two areas should be the same iff q is inside the triangle P0P1P2, and we can avoid repetitive calculation by saving the area of P0P1P2 inside its data structure.