# Processing Month, Day 27 - Mesh Basics

Posted by Jan Vantomme on 27 May 2011.
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Today we’ll take a look at how we can use the `QUAD_STRIP` and `TRIANGLE_STRIP` modes with `beginShape()` to draw a mesh to the screen. This will be useful when you want to get started with drawing 3D shapes with Processing. This first example will draw a strip made from rectangles.

``` beginShape(QUAD_STRIP);for (int i = 0; i < 11; i++) {    vertex( i * 40, 0 );    vertex( i * 40, 60 );}endShape();  ``` The second example uses the `TRIANGLE_STRIP` mode and draws the same thing to the screen, only with triangles now.

``` beginShape(TRIANGLE_STRIP);for (int i = 0; i < 11; i++) {    vertex( i * 40, 0 );    vertex( i * 40, 60 );}endShape();  ``` If we want to draw a grid, we need nested for loops. The code is almost the same as in the first example. The y-coordinate of each vertex gets calculated now and we wrapped an extra for loop around the code. Note that the outer for-loop only runs to 10, not to 11. If it would run to 11, we would render a grid of 11 x 10 rectangles.

``` for (int j = 0; j < 10; j ++) {    beginShape(QUAD_STRIP);    for (int i = 0; i < 11; i++) {        vertex( i * 40, j * 40 );        vertex( i * 40, (j+1) * 40 );    }    endShape();}  ``` If you want to render the grid with triangles, replace `QUAD_STRIP` in the previous example to `TRIANGLE_STRIP` to get the result in the image below. 