mayavi smart downsampling for volumetric rendering

Good afternoon,

I am accustomed to calling:
ix,iy,iz=np.indicies(src)
mlab.pipeline.volume(mlab.pipeline.scalar_field(ix,iy,iz,src))

My new problem is that src is too large. Specifically the np.indicies call runs out of memory, but I suspect the second line would have problems as well.

The obvious solution is to try downsample when the user is zoomed out and show full resolution when the user is zoomed closer in. I'm sure someone has tried to write this before. It might even be literally built into mayavi but I don't know it.

What are my best options for doing this?

Thanks,
Chris