update README

Author: sjkelly

README.md

@@ -8,6 +8,52 @@ This package provides meshing algorithms for use on distance fields.
 Including:
 * [Marching Tetrahedra](https://en.wikipedia.org/wiki/Marching_tetrahedra)
 * [Marching Cubes](https://en.wikipedia.org/wiki/Marching_cubes)
+* [Naive Surface Nets](https://0fps.net/2012/07/12/smooth-voxel-terrain-part-2/)
+
+## Interface
+
+This package is tightly integrated with [GeometryTypes.jl](https://github.com/JuliaGeometry/GeometryTypes.jl).
+
+All algorithms operate on `SignedDistanceField` and output a concrete `AbstractMesh`. For example:
+
+```
+using Meshing
+using GeometryTypes
+using LinearAlgebra: dot, norm
+using FileIO
+
+# generate an SDF of a sphere
+sdf_sphere = SignedDistanceField(HyperRectangle(Vec(-1,-1,-1.),Vec(2,2,2.))) do v
+    sqrt(sum(dot(v,v))) - 1 # sphere
+end
+
+m = GLNormalMesh(sdf_sphere, MarchingCubes())
+
+save("sphere.ply",m)
+```
+
+The general API is ``(::Type{MT})(sdf::SignedDistanceField, method::AbstractMeshingAlgorithm) where {MT <: AbstractMesh}``
+
+For a full listing of concrete `AbstractMesh` types see [GeometryTypes.jl mesh documentation](http://juliageometry.github.io/GeometryTypes.jl/latest/types.html#Meshes-1).
+
+### Meshing Algorithms
+
+Three meshing algorithms exist:
+* `MarchingCubes()`
+* `MarchingTetrahedra()``
+* `NaiveSurfaceNets()`
+
+Each takes an optional `iso` and `eps` parameter, e.g. `MarchingCubes(0.0,1e-6)`.
+
+Here `iso` controls the offset for the boundary detection. By default this is set to 0. `eps` is the detection tolerance for a voxel edge intersection.
+
+Below is a comparison of the algorithms:
+
+| Algorithm          | Accurate | Manifold | Performance Penalty | Face Type |
+|--------------------|----------|----------|---------------------|-----------|
+| MarchingCubes      | Yes      | No       | ~4x                 | Triangle  |
+| MarchingTetrahedra | Yes      | Yes      | ~12x                | Triangle  |
+| NaiveSurfaceNets   | No       | No       | 1x                  | Quad      |
 
 ## Credits