US Patent 7605820 Creating texture data outside of a chart boundary

Discontinuities along texture mapped seams of three-dimensional models may be reduced by creating and sampling texture data outside of chart boundaries. When a texel center is not within a chart boundary (a group of connected triangles in texture space) a phantom face is generated that includes the texel center. Phantom texture coordinates are created for each texel center that is covered by the phantom face. The phantom texture coordinates are used to read a texture sample from another chart in texture space that is adjacent to the chart boundary in model space, producing a smooth transition across the seam.