VolumeDensity8 volume = new VolumeDensity8(32, 32, 32);
Region region = new Region(new Vector3DInt16(0, 0, 0, 0), new Vector3DInt16(32, 32, 32, 32));

//Our new density value
byte uDensity = Density8.getMaxDensity();

//Get the old voxel
Density8 voxel = volume.getVoxelAt(16, 16, 16);

//Modify the density
voxel.setDensity(uDensity);

//Wrte the voxel value into the volume
volume.setVoxelAt(16, 16, 16, voxel);

SurfaceMeshPositionMaterialNormal surface = new SurfaceMeshPositionMaterialNormal();
SurfaceExtractorDensity8 surfaceExtractor = new SurfaceExtractorDensity8(volume, region, surface);
surfaceExtractor.execute(); // extract surface
uint indices = surface.getNoOfIndices();
Console.WriteLine("Surface indices: " + indices);