/** * Directional.  *  * Move the mouse the change the direction of the light. * Directional light comes from one direction and is stronger  * when hitting a surface squarely and weaker if it hits at a  * a gentle angle. After hitting a surface, a directional lights  * scatters in all directions.  */void setup() {  size(640, 360, P3D);  noStroke();  fill(204);}void draw() {  noStroke();   background(0);   float dirY = (mouseY / float(height) - 0.5) * 2;  float dirX = (mouseX / float(width) - 0.5) * 2;  directionalLight(204, 204, 204, -dirX, -dirY, -1);   translate(width/2 - 100, height/2, 0);   sphere(80);   translate(200, 0, 0);   sphere(80); }