Crate fast_surface_nets[−][src]

Expand description

A fast, chunk-friendly implementation of Naive Surface Nets on regular grids.

Surface Nets is an algorithm for extracting an isosurface mesh from a signed distance field sampled on a regular grid. It is nearly the same as Dual Contouring, but instead of using hermite (derivative) data to estimate surface points, Surface Nets will do a simpler form of interpolation (average) between points where the isosurface crosses voxel cube edges.

Benchmarks show that surface_nets generates about 20 million triangles per second on a single core of a 2.5 GHz Intel Core i7. This implementation achieves high performance by using small lookup tables and SIMD acceleration provided by glam when doing 3D floating point vector math.

High-quality surface normals are estimated by:

calculating SDF derivatives using central differencing
using bilinear interpolation of SDF derivatives along voxel cube edges

When working with sparse data sets, surface_nets can generate meshes for array chunks that fit together seamlessly. This works because faces are not generated on the positive boundaries of a chunk. One must only apply a translation of the mesh into proper world coordinates for given chunk.

Example Code

use fast_surface_nets::ndshape::{ConstShape, ConstShape3u32};
use fast_surface_nets::{surface_nets, SurfaceNetsBuffer};

// A 16^3 chunk with 1-voxel boundary padding.
pub type ChunkShape = ConstShape3u32<18, 18, 18>;

// This chunk will cover just a single octant of a sphere SDF (radius 15).
let mut sdf = [1.0; ChunkShape::SIZE as usize];
for i in 0u32..(ChunkShape::SIZE) {
    let [x, y, z] = ChunkShape::delinearize(i);
    sdf[i as usize] = ((x * x + y * y + z * z) as f32).sqrt() - 15.0;
}

let mut buffer = SurfaceNetsBuffer::default();
surface_nets(&sdf, &ChunkShape {}, [0; 3], [17; 3], &mut buffer);

// Some triangles were generated.
assert!(!buffer.indices.is_empty());

Crate fast_surface_nets[−][src]

Example Code

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