Functions | |
void | Rotate_Texture_Offaxis (double x, double y, double z, double theta) |
Rotates the represented texture coordinates (vertex parameters) about an arbitrary axis. More... | |
Detailed Description
Function Documentation
◆ Rotate_Texture_Offaxis()
void Rotate_Texture_Offaxis | ( | double | x, |
double | y, | ||
double | z, | ||
double | theta | ||
) |
Rotates the represented texture coordinates (vertex parameters) about an arbitrary axis.
- Parameters
-
x - Vector defining the axis of rotation. Need not be normalized y - z - theta - Angle, in degrees, to rotate about the axis.
DETAILS
Rotate_Texture_Offaxis() modifies a segment's "texture matrix" attribute (see Set_Texture_Matrix() ) that is applied to the (u, v, w) vertex parameters of shells and meshes. In order to give the appearance that a texture is being rotated, the vertex parameters (which don't change their geometric locations) are transformed by the opposite rotation (the matrix adjoint).
Most rotations in HOOPS (the exception is Orbit_Camera() ), no matter whether "texture" or "object", are performed using a left-hand rule. A positive rotation is represented by the direction curved fingers of the left hand are pointing when the thumb points in the positive direction along the axis in question, i.e., counter-clockwise. A negative rotation angle goes the other way. This definition can be reversed with the "Handedness" attribute.