Point-based geometry representations allow to process and visualize 3D models without the need for costly surface reconstruction or triangulation. They are therefore a flexible and efficient alternative to traditional spline-based or mesh-based surface representations . For instance, point-based representations allow for simple and efficient level-of-detail rendering and progressive transmission .
A crucial component for any interactive application using point-based representation is the visualization. Due to the lack of hardware support for point primitives, early point-based rendering techniques were pure software implementations , and hence were too slow for real-time visualization of highly complex data sets. However, the increasing programmability of current graphics hardware (GPU) allows for hardware-accelerated point rendering [3,4], using so-called surface splatting, where each point sample is equipped with a normal vector and a radius, and therefore represents a small circle or ellipse in object space.
High visual quality is and flexible rendering is achieved using multi-pass deferred shading achieved by the inherent anti-aliasing of surface splatting, as well as by per-pixel Phong shading and shadow mapping [5,6]. A systematic description of several rendering approaches is given in the book .
The point-based rendering metaphor, where elliptical splats are generated from simple OpenGL points, has also been successfully applied in scientific visualization. For instance, in molecular visualization, individual atoms and their connections can be represented by sphere and cylinders, respectively, which are generated and rasterized completely on the GPU . Thanks to the high rendering performance, even dynamic (pre-computed) MD simulations of large membrane patches can be visualized in realtime, which we exploited for an interactive "atom-level magnifier tool" in a combined mesoscopic and molecular visualization .
A Survey of Point-Based Techniques in Computer Graphics
Computers & Graphics, Vol. 28, No. 6, pp. 801-814.
Efficient high quality rendering of point sampled geometry
Eurographics Workshop on Rendering 2002, pp. 53-64.
High-Quality Point-Based Rendering on Modern GPUs
Pacific Graphics 2003, pp. 335-343.
Perspective Accurate Splatting
Graphics Interface 2004, pp. 247-254.
Eurographics Symp. on Point-Based Graphics 2004, pp. 25-32.
High-Quality Surface Splatting on Today's GPUs
Eurographics Symp. on Point-Based Graphics 2005, pp. 17-24.
Chapter in Point Based Graphics, Markus Gross, Hanspeter Pfister (Editors)
Elsevier / Morgan Kaufmann, ISBN 0123706041, 2007.
GPU-Based Ray-Casting of Quadratic Surfaces
Eurographics Symp. on Point-Based Graphics 2006, pp. 59-65.
Membrane Mapping: Combining Mesoscopic and Molecular Cell Visualization
Proceedings of Eurographics Workshop on Visual Computing for Biology and Medicine, 2014, pp. 89-96.