Programming Tutorials

NOTE: These tutorials refer to older versions of Voreen and are therefore somewhat outdated. They might still contain some useful information.


Raycasting is a technique to visualize volume data at interactive frame rates and the primary rendering technique in Voreen. For every pixel of the image plane a ray is traced through the scene starting from the viewer. If the ray hits the volume the color of the pixel is calculated by sampling the data values of the ray at a finite number of positions in the volume. On each sample the transfer function is applied and composited with accumulated values of the ray. There are several acceleration techniques to speed up raycasting, e.g., early ray termination and empty space skipping. This tutorial gives a brief overview about GPU-based raycasting in general and describes how it is implemented in Voreen.

  Raycasting Tutorial

Volume API

This tutorial deals with the handling of volumes used by Voreen. This covers the different classes of the volume API, the connection to OpenGL and the used representation as textures, and the loading mechanism.

Volume API Tutorial