Cell Indexing‎ > ‎

Rhombus Index

The Rhombus index is uses UV axis coordinates to address rhombus tiles that cover the ISEA3H.  The Rhombus Index addresses the need to utilize a rectilinear data structure, such as texture mapping and other efficient GPU operations, while maintaining complete coverage over all ISEA3H DGGS cells.


The Rhombus Tile

The Icosahedron faces form the first resolution of 10 rhombus tiles. Each cell using UV axes and a rhombus index. Each cell in the rhombus is given a U,V coordinate U,V:


       

UV coordinate can be integers or floating numbers.


Basic Operations
The PYXIS DGGS SDK includes algebraic expressions and operations to efficiently iterate/traverse over the icosahedron referenced cells covering the globe. 

zoomIn(r,u,v) -> return {r: r + char(floor(3*(u+3*v)), u: 3*u-floor(u*3), v: 3*v-floor(v*3)}
zoomOut(r,u,v) -> var lastDigiit = r[r.length-1]; return {r: r.substr(0,r.length-1); u: (lastDigit%3 + u)/3, v: (lastDigit/3+v)/3 }



Comments