Single precision limits

[areknawo]

Recently I’ve started to create a 3D map with buildings & roads in ThreeJS. For tiles I used GeoJSON. I was converting lat & long to mercator projection and move map simply with OrbitControls. The tile was positioned on certain coordinates and BufferGeometry was holding vertices relative to the center of the tile. Everything was fine when extruding the building. The problem started when I got to displaying roads. GL Lines, as many may know, don’t have many option for customization (width on Windows & cups etc.) so I went with creating lines from triangles. The implementation itself was fine but the roads themselves weren’t so ideal. The greater the zoom was the worse the quality, as GeoJSON data was becoming more and more accurate - the coordinates have more floating point digits too. So, as the mercator values goes upto 8 digits before and even more than that after after floating point. And as this difference is growing and Float32 cuts the rest of coordinates the distortions are briefly seen. I thought about emulating 64 Bit in shader but it isn’t really performant on mobile devices. The other option is to somehow minimize these numbers to 7 significant digits without losing quality. So, any advice or help?