990 likes | 1.11k Views
Learn about Barycentric Coordinates, Homogeneous Coordinates, Boundary Value Interpolation, Wachspress Coordinates, Mean Value Coordinates, and Deformations using Barycentric Coordinates in geometry. Understand their applications, properties, and comparisons in different dimensions.
E N D
Generalized Barycentric Coordinates Dr. Scott Schaefer
Barycentric Coordinates • Given find weights such that • are barycentric coordinates
Barycentric Coordinates • Given find weights such that • are barycentric coordinates Homogenous coordinates
Barycentric Coordinates • Given find weights such that • are barycentric coordinates
Barycentric Coordinates • Given find weights such that • are barycentric coordinates
Barycentric Coordinates • Given find weights such that • are barycentric coordinates
Barycentric Coordinates • Given find weights such that • are barycentric coordinates
Boundary Value Interpolation • Given , compute such that • Given values at , construct a function • Interpolates values at vertices • Linear on boundary • Smooth on interior
Boundary Value Interpolation • Given , compute such that • Given values at , construct a function • Interpolates values at vertices • Linear on boundary • Smooth on interior
Smooth Wachspress Coordinates • Given find weights such that
Smooth Wachspress Coordinates • Given find weights such that
Smooth Wachspress Coordinates • Given find weights such that
Wachspress Coordinates – Summary • Coordinate functions are rational and of low degree • Coordinates are only well-defined for convex polygons • wi are positive inside of convex polygons • 3D and higher dimensional extensions (for convex shapes) do exist
Mean Value Coordinates • Apply Stokes’ Theorem
Comparison convex polygons (Wachspress Coordinates) closed polygons (Mean Value Coordinates)
Comparison convex polygons (Wachspress Coordinates) closed polygons (Mean Value Coordinates)
Comparison convex polygons (Wachspress Coordinates) closed polygons (Mean Value Coordinates)
Comparison convex polygons (Wachspress Coordinates) closed polygons (Mean Value Coordinates)
3D Mean Value Coordinates • Exactly same as 2D but must compute mean vector for a given spherical triangle
3D Mean Value Coordinates • Exactly same as 2D but must compute mean vector for a given spherical triangle • Build wedge with face normals
3D Mean Value Coordinates • Exactly same as 2D but must compute mean vector for a given spherical triangle • Build wedge with face normals • Apply Stokes’ Theorem,