the most common name i found in graphics textbooks is cross product.

so recap, the most common operations with vectors in graphics are two: the dot product and the cross product.

dot/inner/scalar product is the componet-wise product:

a dot b = s (scalar) =

a.x * b.x + a.y * b.y + … =

|a| * |b| * cos(phi)

cross/vector/outer product, gives the plane-bundle where the two vectors are built, or the normal to that plane, wich is basically the same.

a cross b = n (vector) =

(for the 3-space case)

n.x = a.y*b.z - a.z*b.y

n.y = a.z*b.x - a.x*b.z

n.z = a.x*b.y - a.y*b.x

|n| = |a| * |b| * sin(phi)

(^^^ correct me boys if i’m wrong about this ^^^)

DMY

[This message has been edited by dmy (edited 12-21-2000).]