GPU‐based Fast Ray Casting for a Large Number of Metaballs

Abstract

Metaballs are implicit surfaces widely used to model curved objects, represented by the isosurface of a density field defined by a set of points. Recently, the results of particle-based simulations have been often visualized using a large number of metaballs, however, such visualizations have high rendering costs. In this paper we propose a fast technique for rendering metaballs on the GPU. Instead of using polygonization, the isosurface is directly evaluated in a per-pixel manner. For such evaluation, all metaballs contributing to the isosurface need to be extracted along each viewing ray, on the limited memory of GPUs. We handle this by keeping a list of metaballs contributing to the isosurface and efficiently update it. Our method neither requires expensive precomputation nor acceleration data structures often used in existing ray tracing techniques. With several optimizations, we can display a large number of moving metaballs quickly.

Visualization of big SPH simulations via compressed octree grids

“…Most commonly this is performed by resampling particle quantities to a Cartesian proxy grid [5], [6], and then using iso-surface extraction or direct volume rendering. To avoid the memory consumption of a proxy grid, SPH data can be rendered directly by evaluating the SPH kernels at sampling points along the view rays [7], [8]. An iso-surface extraction technique that works directly on the particle set was introduced in [9].…”

A Fast Runtime Visualization of a GPU-Based 3D-FDTD Electromagnetic Simulation

“…When the accumulated permeation rate (alpha value) reaches a threshold defined in advance or the ray falls out of the drawing space, the intensity of the corresponding pixel on the image plane is calculated from the accumulated voxel data at that point. Although the method was not suited for runtime and interactive visualization due to its high computing complexity in past days, high speed rendering is now feasible using GPUs technologies [15].…”

Fast Particle‐based Visual Simulation of Ice Melting

“…Then, the extracted iso-surfaces are rendered by using the ray tracing technique. In the interactive rendering method, in order to achieve interactive feedback, our method employs a GPUbased ray casting method similar to [KSN08]. Fig.…”