All shapes are constructed by connecting a series of vertices. vertex() is used to specify the vertex coordinates for points, lines, triangles, quads, and polygons. It is used exclusively within the beginShape() and endShape() functions.
Drawing a vertex in 3D using the z parameter requires the P3D parameter in combination with size, as shown in the above example.
This function is also used to map a texture onto geometry. The texture() function declares the texture to apply to the geometry and the u and v coordinates set define the mapping of this texture to the form. By default, the coordinates used for u and v are specified in relation to the image’s size in pixels, but this relation can be changed with textureMode().
beginShape(POINTS); vertex(30, 20); vertex(85, 20); vertex(85, 75); vertex(30, 75); endShape();