MeshData.py 文件源码

def sphere(rows, cols, radius=1.0, offset=True):
        """
        Return a MeshData instance with vertexes and faces computed
        for a spherical surface.
        """
        verts = np.empty((rows+1, cols, 3), dtype=float)

        ## compute vertexes
        phi = (np.arange(rows+1) * np.pi / rows).reshape(rows+1, 1)
        s = radius * np.sin(phi)
        verts[...,2] = radius * np.cos(phi)
        th = ((np.arange(cols) * 2 * np.pi / cols).reshape(1, cols)) 
        if offset:
            th = th + ((np.pi / cols) * np.arange(rows+1).reshape(rows+1,1))  ## rotate each row by 1/2 column
        verts[...,0] = s * np.cos(th)
        verts[...,1] = s * np.sin(th)
        verts = verts.reshape((rows+1)*cols, 3)[cols-1:-(cols-1)]  ## remove redundant vertexes from top and bottom

        ## compute faces
        faces = np.empty((rows*cols*2, 3), dtype=np.uint)
        rowtemplate1 = ((np.arange(cols).reshape(cols, 1) + np.array([[0, 1, 0]])) % cols) + np.array([[0, 0, cols]])
        rowtemplate2 = ((np.arange(cols).reshape(cols, 1) + np.array([[0, 1, 1]])) % cols) + np.array([[cols, 0, cols]])
        for row in range(rows):
            start = row * cols * 2 
            faces[start:start+cols] = rowtemplate1 + row * cols
            faces[start+cols:start+(cols*2)] = rowtemplate2 + row * cols
        faces = faces[cols:-cols]  ## cut off zero-area triangles at top and bottom

        ## adjust for redundant vertexes that were removed from top and bottom
        vmin = cols-1
        faces[faces<vmin] = vmin
        faces -= vmin  
        vmax = verts.shape[0]-1
        faces[faces>vmax] = vmax

        return MeshData(vertexes=verts, faces=faces)