Interacting with Volume Data: Deformations using Forward Projection

We present a rendering algorithm for the forward projection of volume deformations. Spatial deformations are modeled by allowing the user to define curve skeletons inside the target object. Our rendering method utilises modern consumer graphics hardware and is integrated into an easy to use interface. In addition, we give an analysis of spatial transfer functions computed on the GPU, and give a solution to the problem of cracks appearing in image space when samples are pulled apart.