Single Sample Seamless Tri-Planar Mapping (UE5)

Here I demonstrate a method of using temporally blended stochastic sampling to achieve tri-planar mapping and texture switching using a single texture sampler. Traditional tri-planar mapping requires a sample for each of the 3 world planes in order to achieve a seamless blend. This can be costly, especially for landscape materials with many textures. By levering frame blending used for TAA, dithering and noise we can achieve a seamless transition with just one sample for all planes. The downside is that the dithering may become momentarily visible upon disocclusion for a few frames while the blending accumulates, especially in areas of high contrast. This technique can also be used to blend samples from arrays to allow landscape materials to seamlessly transition under a single sampler. Inspired by: Timestamps 00:00 Welcome 00:30 The issue with tri-planar mapping: 3 samples per texture 01:15 A typical tri-planar materia