A Go port of the RTIN terrain mesh generator mapbox/martini by mourner.
Additional info on martini can be found at the Observable notebook, "MARTINI: Real-Time RTIN Terrain Mesh", written by mourner. Original algorithm based on the paper "Right-Triangulated Irregular Networks" by Will Evans et. al. (1997).
Sanity checks of porting correctness and static typing nuance by referencing kylebarron's Cython port pymartini.
A mesh consisting of vertices and triangles can be generated from a terrain PNG image.
file, _ := os.Open("data/fuji.png")
img, _, _ := image.Decode(file)
terrain, _ := gmartini.DecodeElevation(img, "mapbox", true)
martini, _ := gmartini.New(gmartini.OptionGridSize(513))
tile, _ := martini.CreateTile(terrain)
mesh := tile.GetMesh(gmartini.OptionMaxError(30))
go get github.com/engelsjk/gmartini
Benchmarking shows comparable results to mapbox/martini for preparation steps and to pymartini for mesh generation.
go test ./benchmark -run TestExecutionTime -vinit tileset: 39.450ms
create tile: 10.201ms
mesh (max error = 0): 14.202ms (vertices: 261880, triangles: 521768)
mesh (max error = 2): 11.739ms (vertices: 176260, triangles: 351014)
mesh (max error = 5): 6.633ms (vertices: 94496, triangles: 187912)
mesh (max error = 10): 3.313ms (vertices: 45107, triangles: 89490)
mesh (max error = 20): 1.329ms (vertices: 17764, triangles: 35095)
mesh (max error = 30): 0.779ms (vertices: 9708, triangles: 19094)
mesh (max error = 50): 0.361ms (vertices: 4234, triangles: 8261)
mesh (max error = 75): 0.191ms (vertices: 2117, triangles: 4094)
mesh (max error = 100): 0.120ms (vertices: 1239, triangles: 2373)
mesh (max error = 250): 0.032ms (vertices: 200, triangles: 359)
mesh (max error = 500): 0.018ms (vertices: 46, triangles: 75)