A sample code for a blog post at eetumaenpaa.fi

MarchingCubesJob.cs

using Eldemarkki.VoxelTerrain.Meshing.Data;
using Eldemarkki.VoxelTerrain.Utilities;
using Eldemarkki.VoxelTerrain.VoxelData;
using Unity.Burst;
using Unity.Collections;
using Unity.Jobs;
using Unity.Mathematics;

namespace Eldemarkki.VoxelTerrain.Meshing.MarchingCubes
{
    [BurstCompile]
    public struct MarchingCubesJob : IJobParallelFor
    {
        [ReadOnly] public VoxelDataVolume<byte> voxelData;
        public byte isolevel;

        public NativeCounter vertexCountCounter;

        [NativeDisableParallelForRestriction, WriteOnly] public NativeArray<MeshingVertexData> vertices;
        [NativeDisableParallelForRestriction, WriteOnly] public NativeArray<ushort> triangles;

        public void Execute(int index)
        {
            int3 voxelLocalPosition = IndexUtilities.IndexToXyz(index, voxelData.Width-1, voxelData.Height-1);

            VoxelCorners<byte> densities = voxelData.GetVoxelDataUnitCube(voxelLocalPosition);

            byte cubeIndex = MarchingCubesFunctions.CalculateCubeIndex(densities, isolevel);
            if (cubeIndex == 0 || cubeIndex == 255)
            {
                return;
            }

            int edgeIndex = MarchingCubesLookupTables.EdgeTable[cubeIndex];

            VertexList vertexList = MarchingCubesFunctions.GenerateVertexList(densities, voxelLocalPosition, edgeIndex, isolevel);

            // Index at the beginning of the row
            int rowIndex = 15 * cubeIndex;

            for (int i = 0; MarchingCubesLookupTables.TriangleTable[rowIndex + i] != -1 && i < 15; i += 3)
            {
                float3 vertex1 = vertexList[MarchingCubesLookupTables.TriangleTable[rowIndex + i + 0]];
                float3 vertex2 = vertexList[MarchingCubesLookupTables.TriangleTable[rowIndex + i + 1]];
                float3 vertex3 = vertexList[MarchingCubesLookupTables.TriangleTable[rowIndex + i + 2]];

                if (!vertex1.Equals(vertex2) && !vertex1.Equals(vertex3) && !vertex2.Equals(vertex3))
                {
                    float3 normal = math.normalize(math.cross(vertex2 - vertex1, vertex3 - vertex1));

                    int triangleIndex = vertexCountCounter.Increment() * 3;

                    vertices[triangleIndex + 0] = new MeshingVertexData(vertex1, normal);
                    triangles[triangleIndex + 0] = (ushort)(triangleIndex + 0);

                    vertices[triangleIndex + 1] = new MeshingVertexData(vertex2, normal);
                    triangles[triangleIndex + 1] = (ushort)(triangleIndex + 1);

                    vertices[triangleIndex + 2] = new MeshingVertexData(vertex3, normal);
                    triangles[triangleIndex + 2] = (ushort)(triangleIndex + 2);
                }
            }
        }
    }
}