// set camera position, aim, up. Verify, and make up the true up direction
void GraphicCamera::GetCoordinate(const Vec3d& pos, const Vec3d& aim,
const Vec3d& up){
Vec3d zaixs = pos - aim;
if (zaixs.Norm() < kEPSILON) {
throw "Camera position and aim are the same. Problematic";
exit(1);
}
Vec3d dir = -zaixs.Normalization();
Vec3d _up = up.Normalization();
Vec3d xaxis = dir % _up;
if (xaxis.Norm() < kEPSILON ) {
throw "Up parallel to aim. Wrong parameter";
}
this->pos_ = pos;
this->aim_ = aim;
this->up_ = xaxis.Normalization() % dir; // make it always perpendicular
// to dir
}
