final int addVertex(int x, int y, int z) {
		for (int i1 = 0; i1 < vertexCount; i1++) {
			if (verticesX[i1] == x && y == verticesY[i1] && verticesZ[i1] == z) {
				return i1;
			}
		}

		verticesX[vertexCount] = x;
		verticesY[vertexCount] = y;
		verticesZ[vertexCount] = z;
		maxVertex = 1 + vertexCount;
		return vertexCount++;
	}