Painting and rendering textures on unparameterized models

Abstract

This paper presents a solution for texture mapping unparameterized models. The quality of a texture on a model is often limited by the model's parameterization into a 2D texture space. For models with complex topologies or complex distributions of structural detail, finding this parameterization can be very difficult and usually must be performed manually through a slow iterative process between the modeler and texture painter. This is especially true of models which carry no natural parameterizations, such as subdivision surfaces or models acquired from 3D scanners. Instead, we remove the 2D parameterization and store the texture in 3D space as a sparse, adaptive octree. Because no parameterization is necessary, textures can be painted on any surface that can be rendered. No mappings between disparate topologies are used, so texture artifacts such as seams and stretching do not exist. Because this method is adaptive, detail is created in the map only where required by the texture painter, conserving memory usage.

TileTrees

“…While being extremely simple to compute, this projection can handle successfully non trivial cases, including a full sphere. It also handles correctly two-sided thin surfaces, as illustrated Figure 4 -a difficult case with previous volume approaches [Benson and Davis 2002;DeBry et al 2002]. In fact, it can even texture the back and front sides of a triangle differently.…”

“…To enable texturing of implicit surfaces and avoid explicit parameterization altogether, Benson et al [Benson and Davis 2002] and DeBry et al [DeBry et al 2002] proposed to encode texture data in an octree surrounding the surface. This provides low distortion and adaptive texturing, at the expense of a space and time overhead: The tree contains many unused entries in its nodes, and accessing the data requires a long chain of indirections.…”

Interpolation and parallel adjustment of center-sampled trees with new balancing constraints

“…Instead, uniform resolution is forced at those locations requiring interpolation [3,10,36]. To prevent large accuracy jumps caused by large resolution differences, trees are often constrained by 2-to-1 balancing that allows only one level difference between adjacent cells [16,31].…”

Skeleton-based 3D Surface Parameterization Applied on Texture Mapping

“…Some works try to solve the seam problem by boundary color duplication [Purnomo et al 2004], [Carr and Hart 2002] and [Piponi and Borshukov 2000]. Another group of approaches use an octree structure [Benson and Davis 2002], [Debry et al 2002] and [Lefebvre and Dachsbacher 2007] to store the data instead of mapping the surface into a planar domain. An alternative way to texture mapping was presented in [Yuksel et al 2010], where the color sample positions are defined directly on the 3D surface.…”