Any idea how to smoothly cap off marching cubes mesh for planet where openings are forming close to radius' magnitude?

[jamesfoti]

My project using using FastNoiseLite for the noise generation and this is the code for generating the densities:

	public void SetVoxelDensities()
	{
		foreach (Voxel voxel in _voxels)
		{
			for (int i = 0; i < voxel.VoxelVertices.Length; i++)
			{
				if (!voxel.VoxelVertices[i].HasBeenTerraformed)
				{
					Vector3 position = voxel.VoxelVertices[i].Position;

					float xSample = position.x + _parentPlanet.PlanetSettings.Offset.x;
					float ySample = position.y + _parentPlanet.PlanetSettings.Offset.y;
					float zSample = position.z + _parentPlanet.PlanetSettings.Offset.z;

					float noise = _parentPlanet.FastNoiseLite.GetNoise(xSample, ySample, zSample);

					voxel.VoxelVertices[i].Density = position.magnitude - _parentPlanet.PlanetSettings.RadiusInRealWorld + (_parentPlanet.PlanetSettings.NoiseScale * noise);
				}
			}
		}
	}

Here is the problem when I increase the iso level:

If I sort of “cap” off the edges by modifying the code like this, then it sort of works but without the smoothness:

public void SetVoxelDensities()
{
	foreach (Voxel voxel in _voxels)
	{
		for (int i = 0; i < voxel.VoxelVertices.Length; i++)
		{
			if (!voxel.VoxelVertices[i].HasBeenTerraformed)
			{
				Vector3 position = voxel.VoxelVertices[i].Position;

				float xSample = position.x + _parentPlanet.PlanetSettings.Offset.x;
				float ySample = position.y + _parentPlanet.PlanetSettings.Offset.y;
				float zSample = position.z + _parentPlanet.PlanetSettings.Offset.z;

				float noise = _parentPlanet.FastNoiseLite.GetNoise(xSample, ySample, zSample);

				if (position.magnitude >= _parentPlanet.PlanetSettings.RadiusInRealWorld)
				{
					voxel.VoxelVertices[i].Density = _parentPlanet.PlanetSettings.IsoLevel + 1; // Or whatever number to cause it to go over iso level.
				} else
				{
					voxel.VoxelVertices[i].Density = position.magnitude - _parentPlanet.PlanetSettings.RadiusInRealWorld + (_parentPlanet.PlanetSettings.NoiseScale * noise);
				}
			}
		}
	}
}

[jamesfoti]

Adding screenshots here b/c Unity won’t let me upload more than one on a given post/reply:

Set of control variables where no issue arrises:

[jamesfoti]

Adding screenshots here b/c Unity won’t let me upload more than one on a given post/reply:

Here is the problem when I increase the noise scale:

[jamesfoti]

Adding screenshots here b/c Unity won’t let me upload more than one on a given post/reply:

Here is what this looks like with the modifications to the code like mentioned in the original post: