I was wondering what is it about the volume visualization node that seems to give more smooth volume visualizations than say that same volume rendered (left image) which seems to tend to make it look more like particle rendering?

It's not that I favor one or the other in terms of results….but even after trying different settings of voxel size, density, number of points used, etc., overall it seems that rendered images tend towards a rendering of particles compared to the volume visualization node which seems to look more like what I would expect from voxels.

Probably stochastic sampling on Mantra is causing less dense areas to look like “particles” if it doesn't have enough samples

The viewport is probably being down sampled if the volume is very high resolution.

Thanks guys…must be because of high resolution.

Although it was rendered with Karma, I noticed the same with mantra.

Couldn't find anything related to stochastic in Karma, although I did try some different options on the Karma node and cranked up some values related to volumes in the Render Geometry Settings to no avail.