Match mlab.pipeline.volume image position to the extent in mlab.points3d
my volume image is plot by mlab.pipeline.volume(mlab.pipeline.scalar_field(dd)). dd is a (30,30,30) array of my data points' density. My data points are plotted by mlab.points3d(data[:,0],data[:,1],data[:,2],color=(0,1,1),mode='point',extent=(-10,10, -10,10, -10,10)). How can I make the two images match? Changing extent to (1,30, 1,30, 1,30) still can not match them, also the outlines are the same for the two images.