An adaptive dandelion model for reconstructing spherical terrain-like visual hull surfaces

In this paper we present an adaptive dandelion model for reconstructing spherical terrain-like visual hull (VH) surfaces. The dandelion model represents a solid by a pencil of organized line segments emitted from a common point. The directions and the topology of the line segments are derived from the triangle facets of a geodesic sphere, which are recursively subdivided until the desired precision is achieved. The initial lines are cut by silhouettes in 2D and then lifted back to 3D to determine the ending points of the line segments defining sampling points on the spherical terrain-like VH surface. A mesh model can be easily constructed from the dandelion model. Our algorithm has the advantages of controllable precision, adaptive resolution, simplicity and speediness. We validate our algorithm by theories and experiments.