Matlab's volume visualization got a big boost with volshow a couple years ago, if you have the image processing toolbox. Using the volume V from the comment above, use:
There's a lot of rendering options. For example, I frequently prefer using a MIP's on a black background. E.g. try:
volshow(randn(100, 100, 100), 'Renderer', 'MaximumIntensityProjection', 'BackgroundColor', [0, 0, 0]);
It's tricker to visualize volume data if you have RGB voxels but there are some FEX options out there.