protected void addVertices(Vertex[] vertices, int[] indices,
			boolean calcNormals) {
		if (calcNormals) {
			calcNormals(vertices, indices);
		}

		size = indices.length;
		
		glBindBuffer(GL_ARRAY_BUFFER, vbo);
		glBufferData(GL_ARRAY_BUFFER, Util.createFlippedBuffer(vertices),
				GL_STATIC_DRAW);

		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
		glBufferData(GL_ELEMENT_ARRAY_BUFFER,
				Util.createFlippedBuffer(indices), GL_STATIC_DRAW);
		

	}