Visualization Handbook

9

Multidimensional Transfer Functions for Volume Rendering

JOE KNISS, GORDON KINDLMANN and CHARLES D. HANSEN,     Scientific Computing and Imaging Institute, University of Utah

9.1 Introduction

Direct volume rendering has proven to be an effective and flexible visualization method for 3D scalar fields. Transfer functions are fundamental to direct volume rendering because their role is essentially to make the data visible: by assigning optical properties like color and opacity to the voxel data, the volume can be rendered with traditional computer graphics methods. Good transfer functions reveal the important structures in the data without obscuring them with unimportant regions. To date, transfer functions have generally been limited to 1D ...