Visualization of 3D densities

Hi all,

I’m looking for information about 3D density visualizations.
I don’t ask an aesthetic question here, but more about some best practices or technical experiences around that.

I thought about representing these using:

  • density map as slices (one slice = a png file with density as
  • each element simulated by a particle and visualizing particles with some glowing effect if there are a lot of particles, the “volumic matter" seems to be brighter etc)

Anyone ?
Any ideas, technic would be interesting.


Hi Julien,

ofxVolumetrics does load sliced png images on to GPU buffer and render it as 3D.

I wrote an extension to cut the volumetric 3D from any direction but I’m lazy so it’s not merged yet:


the visualiztion technique is called ‘Volume Rendering’, the wikipedia article has quite some information on it:

Also talks about optimizations etc. The only two techniques of which I know how they work are

  1. slices based approach, where you render a stack of semi-transparent textures oriented towards the user, slicing through the volume data and mapping the scalar field value to texture color with what is called a lookup-table (LUT)
  2. raycasting based approach, where you sample the volume data along sight rays originating in your camera center and going through each pixel on your projection place. This approach I think has more potential for optimization since you might terminate your rays early, can be better parallelized using fragment shaders for the per-pixel compuation, allows e.g. supersampling/antialiasing and can be dynamically adapted for a quality / performance tradeoff
    You might conduct additional research about more recent state of the art.

There is an implementation in VTK afaik (

Edit: Oh yeah, this one:

Have fun!