Introduction
Solutions for session 10.
Exercises
Source code of the exercises.
Exercise 1: Spinning Cube
/*************************
* Extra motion variables
*************************/
float scalefactor = 1.0; // zooming factor
float a = 0; // rotation parameter
void draw() {
// ...
/**********************************
* make cube turn counterclockwise
**********************************/
translate(0,-cos(a),sin(a));
a += 0.01;
/*******************
* make cube rotate
*******************/
rotateX(cos(a)*radius);
rotateY(sin(a)*radius);
rotateZ(cos(tiltspeed * angle) * tilt);
/*********************
* Zooming in and out
*********************/
scale(cos(scalefactor), cos(scalefactor), cos(scalefactor));
scalefactor += 0.01;
drawCube();
}
Exercise 2: 3D Sierpinski Triangle
void recursive_tri(int i) {
if (i <= 1) { /* Base case: draw a pyramid */
beginShape(TRIANGLES);
fill(1.0f, 0.0f, 0.0f);
vertex(-80.0, -80.0, 80.0);
fill(0.0f, 1.0f, 0.0f);
vertex(80.0, -80.0, 80.0);
fill(0.0f, 0.0f, 1.0f);
vertex(0.0, 80.0, 0.0);
fill(1.0f, 0.0f, 0.0f);
vertex(80.0, -80.0, 80.0);
fill(0.0f, 1.0f, 0.0f);
vertex(0.0, -80.0, -80.0);
fill(0.0f, 0.0f, 1.0f);
vertex(0.0, 80.0, 0.0);
fill(1.0f, 0.0f, 0.0f);
vertex(0.0, -80.0, -80.0);
fill(0.0f, 1.0f, 0.0f);
vertex(-80.0, -80.0, 80.0);
fill(0.0f, 0.0f, 1.0f);
vertex(0.0, 80.0, 0.0);
fill(1.0f, 0.0f, 0.0f);
vertex(-80.0, -80.0, 80.0);
fill(0.0f, 1.0f, 0.0f);
vertex(80.0, -80.0, 80.0);
fill(0.0f, 0.0f, 1.0f);
vertex(0.0, -80.0, -80.0);
endShape();
} else {
--i;
pushMatrix(); /* draw lower front left */
translate(-40.0, -40.0, 40.0);
scale(0.5, 0.5, 0.5);
recursive_tri(i);
popMatrix();
pushMatrix(); /* draw lower front right */
translate(40.0, -40.0, 40.0);
scale(0.5, 0.5, 0.5);
recursive_tri(i);
popMatrix();
pushMatrix(); /* draw lower back middle */
translate(0.0, -40.0, -40.0);
scale(0.5, 0.5, 0.5);
recursive_tri(i);
popMatrix();
pushMatrix(); /* draw top-middle */
translate(0.0, 40.0, 0.0);
scale(0.5, 0.5, 0.5);
recursive_tri(i);
popMatrix();
}
}
The solutions to the C exercises can be found here.
