code: public static GVRMesh createQuad(GVRContext gvrContext, float width, float height) {
          GVRMesh mesh = new GVRMesh(gvrContext);
  
          float[] vertices = { width * -0.5f, height * 0.5f, 0.0f, width * -0.5f,
                  height * -0.5f, 0.0f, width * 0.5f, height * 0.5f, 0.0f,
                  width * 0.5f, height * -0.5f, 0.0f };
          mesh.setVertices(vertices);
  
          final float[] normals = { 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,
                  0.0f, 1.0f, 0.0f, 0.0f, 1.0f };
          mesh.setNormals(normals);
  
          final float[] texCoords = { 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,
                  1.0f };
          mesh.setTexCoords(texCoords);
  
          char[] triangles = { 0, 1, 2, 1, 3, 2 };
          mesh.setIndices(triangles);
  
          return mesh;
      }
docs: Creates a quad consisting of two triangles, with the specified width and
  height.
  
  @param gvrContext current {@link GVRContext}
  
  @param width
  the quad's width
  @param height
  the quad's height
  @return A 2D, rectangular mesh with four vertices and two triangles