Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
696
3D Primitives
The 3D Primitives section only includes three functions:
box()
sphere()
sphereDetail()
The box() and sphere() functions generate simple 3D objects. These are not simulated 3D
forms, but are actually based on 3D geometry. Thus, to use these functions, you need to
specify either the P3D or OPENGL rendering mode in the size() function call. If you use
OPENGL, you also need to import the OPENGL library (via the Sketch ➤ Import Library ➤
opengl menu option).
The SphereDetail() function controls the level of detail, or number of vertices, used to
generate the sphere, which is constructed out of triangles that all fit together in a mosaic
pattern (called tessellated triangles). Here’s a little example of some spinning stuff, using
all three of the 3D primitive functions (see Figure A-7). The outer ring of spheres in the
example illustrates the use of the sphereDetail() function. Each of the objects in the ring
is technically a sphere, but by setting the sphereDetail value very low, you get a more
rigid, less sphere-like form.
/* Spinning 3D Stuff
Ira Greenberg, October 9, 2006 */
float px, py, angle;
void setup(){
size(400, 400, P3D);
noFill();
stroke(255);
}
void draw(){
background(0);
translate(width/2, height/2);
pushMatrix();
rotateY(frameCount*PI/150);
rotateX(frameCount*PI/150);
box(100, 100, 100);
pushMatrix();
rotateY(-frameCount*PI/10);
rotateX(PI/4);
box(45, 15, 65);
popMatrix();
popMatrix();