GPU Pro 4

2

II

Real-Time Ptex and

Vector Displacement

Karl Hillesland

2.1 Introduction

A fundamental texture authoring problem is that it’s difficult to unwrap a mesh

with arbitrary topology onto a continuous 2D rectangular texture domain. Meshes

are broken into pieces that are unwrapped into “charts” and packed into a rect-

angular texture domain as an “atlas” as shown in Figure 2.4(b). Artists spend

time setting up UVs to minimize distortion and wasted space in the texture when

they should ideally be focusing on the actual painting and modeling.

Another problem is that edges of each chart in the atlas introduce seam arti-

facts. This seam problem becomes much wor ...