MeshData.py 文件源码

def cylinder(rows, cols, radius=[1.0, 1.0], length=1.0, offset=False):
        """
        Return a MeshData instance with vertexes and faces computed
        for a cylindrical surface.
        The cylinder may be tapered with different radii at each end (truncated cone)
        """
        verts = np.empty((rows+1, cols, 3), dtype=float)
        if isinstance(radius, int):
            radius = [radius, radius] # convert to list
        ## compute vertexes
        th = np.linspace(2 * np.pi, 0, cols).reshape(1, cols)
        r = np.linspace(radius[0],radius[1],num=rows+1, endpoint=True).reshape(rows+1, 1) # radius as a function of z
        verts[...,2] = np.linspace(0, length, num=rows+1, endpoint=True).reshape(rows+1, 1) # z
        if offset:
            th = th + ((np.pi / cols) * np.arange(rows+1).reshape(rows+1,1))  ## rotate each row by 1/2 column
        verts[...,0] = r * np.cos(th) # x = r cos(th)
        verts[...,1] = r * np.sin(th) # y = r sin(th)
        verts = verts.reshape((rows+1)*cols, 3) # just reshape: no redundant vertices...
        ## 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

        return MeshData(vertexes=verts, faces=faces)