code: function containsNormal(normal, normals) {
  	let n;
  	
  	for (n = 0; n < normals.length; n++) {
  		if (!normals[n].ignore && Vector.dot(normal, normals[n]) === 1) {
  			return true;
  		}
  	}
  	
  	return false;
  }
docs: Determine whether a normal is contained in a set of normals.
  
  Skips over ignored normals.
  
  @param {Object} normal    - The normal to look for.
  @param {Object[]} normals - The normals to search.
  @return {boolean} Whether the normal is in the list of normals.