Voxel-based Representation, Display and Thickness Analysis of Intricate Shapes Abstract

This paper presents a novel voxel-based representation scheme coupled with voxelisation, display and geometric algorithms for the purpose of thickness analysis of very complex free form shapes. The binary voxel model is stored as a stack of voxel layers represented as bit-arrays. Polygonal solid models obtained from a CAD system or 3D scanning are converted into voxel format with a maximum resolution of 1000 (overall volume of 1 billion voxels) in less than 2 minutes. Near realtime visualization of the voxel model is achieved by direct point rendering using a look-up table based on a finite set of neighbour voxel configurations. This gives better images than simple cube face display that has blocky appearance. Geometric computation functions have been developed to perform thickness analysis in terms of cross-sectional visualisation, progressive skin removal and radiography with minimum, maximum and total thickness along an orthographic direction. Testing of the algorithms for intricate shapes like a Ganesha idol, pelvic bone and cylinder block gave satisfactory results. The voxel based framework can be coupled to a standard CAD system, providing additional capabilities to product designers. Keywords: Voxel, Solid modeling, Geometric reasoning, Computer-Aided Design. 1