camera_utils.py 文件源码

def points_and_normals(self): 
        """
        Returns the point/normals parametrization for planes, 
        including clipped zmin and zmax frustums

        Note: points need to be in CCW
        """

        nv1, fv1 = self._front_back_vertices
        nv2 = np.roll(nv1, -1, axis=0)
        fv2 = np.roll(fv1, -1, axis=0)

        vx = np.vstack([fv1-nv1, nv2[0]-nv1[0], fv1[2]-fv1[1]])
        vy = np.vstack([fv2-fv1, nv2[1]-nv2[0], fv1[1]-fv1[0]])
        pts = np.vstack([fv1, nv1[0], fv1[1]])

        # vx += 1e-12
        # vy += 1e-12

        vx /= np.linalg.norm(vx, axis=1).reshape(-1,1)
        vy /= np.linalg.norm(vy, axis=1).reshape(-1,1)

        normals = np.cross(vx, vy)
        normals /= np.linalg.norm(normals, axis=1).reshape(-1,1)
        return pts, normals