Quote Originally Posted by User137
Noo, there is now variable in both functions that i don't understand. P1.PP in first code and m_Plane.D in C++ source. They must be some single floating point value from plane but what is it?
PP stands for "producto punto" in spanish, that means "dot product". For your C++ code the D must stand for dot product. The plane is defined with just the Normal of the plane, which is a 3D vector, and the dot product.

The author is using integer arithmetic, that's why he uses those Int64.

Anyway, it's great it works for you!