Authors:
Roberto Nisxota Menegais
;
Flavio Paulus Franzin
;
Lorenzo Schwertner Kaufmann
and
Cesar Tadeu Pozzer
Affiliation:
Curso de Ciência da Computação, Universidade Federal de Santa Maria, Santa Maria, Brazil
Keyword(s):
Mesh Generation, Large Scale, Rasterization, GIS.
Abstract:
Meshes representing the water plane for rivers and lakes are used in a broad range of graphics applications (e.g., games and simulations) to enhance the visual appeal of 3D virtual scenarios. These meshes can be generated manually by an artist or automatically from supplied vector data (e.g. GIS data - Geographic Information System), where rivers and lakes are represented by polylines and polygons, respectively. In automated solutions, the polylines and polygons are extruded and then merged, commonly using geometric approaches, to compose a single polygonal mesh, which is used to apply the water shaders during the rendering process. The geometric approaches usually fail to present scalability for large datasets with a high vertex and feature count. Also, these approaches require specific algorithms for dealing with river-river and river-lake junctions between the entities. In opposition to geometric approaches, in this paper, we propose a raster-based solution for efficient offline m
esh generation for lakes and rivers, represented as polygons and polylines, respectively. The solution uses a novel buffering algorithm for generating merged waterbodies from the vector data. A modification of the Douglas-Peucker simplification algorithm is applied for reducing the vertex count and a constrained Delaunay triangulation for obtaining the triangulated mesh. The algorithm is designed with a high level of parallelism, which can be exploited to speed up the generation time with a multi-thread processor and GPU computing. The results show that our solution is scalable and efficient, generating seamless polygonal meshes for lakes and rivers in arbitrary large scenarios.
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