Complete Polygonal Scene Voxelization

Abstract

We present a fast and robust tool for automatically converting complete polygonal scenes into volumet ric representations. A wide range of scenes are handled by storing the st atus (inside/ outside) of th e volumetric space areas in the cells of an octree. The algori thm first looks for a point in the scene for which t he status can be univocally determined. When such a point is found , it propagates its stat us to the surrounding visible cells. This iterative two-step procedure is repeated for different parts of the scene until the status of all the cells has been determined. The algorithm's advantage is t he coherence with the rendered geometry; it can handle compl ex geometry and exhibits robus t solutions for a broad range of scenes contai ning numerous artifacts, such as cracks , holes, overlapping geometries, interpenetrating meshes, double walls, and fuzzy borders.

Automatic portal generation for 3D audio – from triangle soup to a portal system

“…For example, in the second version of the Unreal Engine [16], portal construction was done with the help of a level editor built into the engine. Although a method of generating portals for arbitrary scenes was described in 2002 [14], use of the automatic generation of portals is not widespread yet in the video game industry due to difficulties associated with the proper implementation of such techniques. In the literature, a similar algorithm for automatic portal generation has been described [8,32].…”

“…The proposed method is based on the voxelization of the input geometry [14] and then computing the distance field [4]; i.e., assigning the shortest distance to any wall in the scene for each voxel. It is worth mentioning that the same voxelization can also be used to automatically generate a simplified geometry (through the so-called re-meshing), which can then be used in other algorithms (such as OC visibility [41]).…”

“…Also, it should be noted that the described 3D extension of the Watershed algorithm is referring to the maxima, while in the original Watershed algorithm [6,14], minima are used (in our example, minima can be used by inverting the distance sign).…”

“…On the right -a point is inside the area even though the line connecting it with one of the area cuboids intersects the scene geometry. This situation cannot occur if a special type of voxelization is used [14] or when thin-wall usage in the input geometry is forbidden.…”

“…The OC solution is popular and has been implemented in a number of game engines (e.g., CryENGINE). An algorithm for automatic portal placement was already suggested by D. Haumont [13,14]. Automated solutions, which allow for eliminating errors caused by oversights during manual editing, can limit the time an artist spends on this purpose and facilitate changes in the projects levels.…”