void Matrix4x4::LookAt(const Vector4 & vFrom, const Vector4 & vTo, const Vector4 & vUp)
{
Vector4 vZ = Normalise(vFrom - vTo);
//vZ.DumpVector4("vZ");
Vector4 vX = Normalise(vUp.Cross(vZ));
//vX.DumpVector4("vX");
Vector4 vY = vZ.Cross(vX);
//vY.DumpVector4("vY");
elem[0][0] = vX.x; elem[0][1] = vY.x; elem[0][2] = vZ.x; elem[0][3] = 0;
elem[1][0] = vX.y; elem[1][1] = vY.y; elem[1][2] = vZ.y; elem[1][3] = 0;
elem[2][0] = vX.z; elem[2][1] = vY.z; elem[2][2] = vZ.z; elem[2][3] = 0;
elem[3][0] = -vX.Dot3(vFrom);
elem[3][1] = -vY.Dot3(vFrom);
elem[3][2] = -vZ.Dot3(vFrom);
elem[3][3] = 1;
}
void Quaternion::Align(Vector3 v1, Vector3 v2)
{
if (v1 == v2) {
s = 1.0f;
x = 0.0f;
y = 0.0f;
z = 0.0f;
} else {
Vector4 A = Vector4(v1).Normalise();
Vector4 B = Vector4(v2).Normalise();
Quaternion res(acos(A.Dot3(B)),A.Cross(B));
s = res.s;
x = res.x;
y = res.y;
z = res.z;
}
}