Introduction

Volume rendering techniques are used in various domains in biomedical and engineering disciplines. They are often used in biomedical imaging to visualize the CT/MRI datasets. In mechanical engineering, they are used to visualize intermediate results from FEM simulations, flow, and structural analysis. With the advent of GPU, all of the existing models and methods of visualization were ported to GPU to harness their computational power. This chapter will detail several algorithms that are used for volume visualization on the GPU in OpenGL Version 3.3 and above. Specifically, we will look at three widely used methods including 3D texture slicing, single-pass ray casting with alpha compositing as well as isosurface rendering, and splatting.

After looking at the volume rendering methods, we will look at volume classification by implementing transfer functions. Polygonal isosurfaces are also often generated to extract out classified regions, for example, cellular boundaries. We, therefore...