Surface Reconstruction from Constructive Solid Geometry for Interactive Visualization

A method is presented for constructing a set of triangles that closely approximates the surface of a constructive solid geometry model. The method subdivides an initial triangulation of the model’s primitives into triangles that can be classified accurately as either on or off of the surface of the whole model, and then recombines these small triangles into larger ones that are still either entirely on or entirely off the surface. Subdivision and recombination can be done in a preprocessing step, allowing later rendering of the triangles on the surface (i.e., the triangles visible from outside the model) to proceed at interactive rates. Performance measurements confirm that this method achieves interactive rendering speeds. This approach has been used with good results in an interactive scientific visualization program

Linear-time CSG rendering of intersected convex objects

The Sequenced Convex Subtraction(SCS) algorithm is a hardware based multi-pass image-space lgorithm for general purpose Constructive Solid Geometry (CSG)Rendering. Convex objects combined by volumetric intersection, difference and union are rendered in real-time without b-rep re-processing. OpenGL stencil and depth testing is used to determine the visible surface for each pixel on the screen. This paper introduces a specialised algorithm for CSG Rendering of intersected convex objects,we call SCS-Intersect. This new technique requires linear time with respect to the number of intersections. SCS-Intersect is primarily of interest as an optimisation to the SCS algorithm for rendering CSG trees of convex objects. A revised formulation of the SCS CSG Rendering algorithm is presented in this pape

An image-space algorithm for hardware-based rendering of constructive solid geometry

A new approach to image-space hardware-based rendering of Constructive Solid Geometry (CSG) models is presented. The work is motivated by the evolving functionality and performance of computer graphics hardware. This work is also motivated by a specific industrial application --- interactive verification of five axis grinding machine tool programs. The goal is to minimise the amount of time required to render each frame in an animation or interactive application involving boolean combinations of three dimensional shapes. The Sequenced Convex Subtraction (SCS) algorithm utilises sequenced subtraction of convex objects for the purpose of interactive CSG rendering. Concave shapes must be decomposed into convex shapes for the purpose of rendering. The length of Permutation Embedding Sequences (PESs) used as subtraction sequences are shown to have a quadratic lower bound. In ma ny situations shorter sequences can be used, in the best case linear. Approaches to subtraction sequence encoding are presented including the use of object-space overlap information. The implementation of the algorithm is experimentally shown to perform better on modern commodity graphics hardware than previously reported methods. This work also examines performance aspects of the SCS algorithm itself. Overall performance depends on hardware characteristics, the number and spatial arrangement of primitives, and the structure and boolean operators of the CSG tree