Transfer functions

This is some images of the transferfunctions that Wang, Ruman and I did in our course in Scientific Visualization, a course held by Ken Museth, a real celebrity within the CG community.







This was implemented in VTK using ray casting (one of the three methods for direct volume rendering that VTK supports) by letting the rays be terminated after a certain threshold value. Often the data for volume rendering is simply fields of scalars. To find a suitable transfer function is not easy but important. Transfer functions tell how the scalar values are mapped to the opacity and colour in the image. We need three functions to map respective colour in RGB and one for the opacity.