CADjs
Cloning and for loops
wheel, hub and spoke assembly
g1 = cube(5);
g2=cylinder(1,20);
g3=cylinder(1,20);
g4=cylinder(20,2);
g5=cylinder(10,2);
g2.rotateX(90);
g3.rotateZ(90);
g=g4.difference(g5);
g=g.union(g1);
g=g.union(g2);
g=g.union(g3);
g.display();
Question
Idea of Cloning
g1 = cylinder(0.5,0.5);
g1.display();
Want to create another similar cylinders, but translated
g1 = cylinder(0.5,0.5);
g1.display();
g2 = g1;//make a copy?
g2.translate(1);//translate g2
g1 = cylinder(0.5,0.5);
g1.display();
g2 = g1.clone();//makes a true copy
g2.translate(1);// translate g2, but not g1
g2.display();
g2 = g1; … does not make copy
g2 is exactly the same as g1
Translating g2 will also translate g1
Idea of Copies
g1 = cylinder(0.5,0.5);
g1.display();
g2 = g1.clone();//makes a true copy
g2.translate(1);// translate g2, but not g1
g2.display();
g3 = g1.clone();//
g3.translate(2);
g3.display();
… can continue, but better to use for loops!
for loops
‘for’ loop
Start at i = 0
Stop when i = 5
Increase i by 1 every loop
for (i = 0;i < 5;i = i+1) {
}
How many times is the loop executed?
i =0
i=1
i=2
i=3
i=4
(stop)
‘for’ loop with Beeper
resetBeeper();
for (i = 0; i < 5; i= i+1){
beep();
}
Increase i by 1 every loop
resetBeeper();
for (i = 0; i < 5; i++){
beep();
}
‘for’ loop with Beeper
resetBeeper();
for (i = 0; i <= 10; i= i+2){
beep();
}
How many beeps?
resetBeeper();
for (i = -5; i <2; i= i+1){
beep();
}
How many beeps?
‘for’ loop with textGeom
for (i = 0; i < 5; i++){
textGeom(i).translateX(i).display();
}
for (i = -2; i <= 2; i = i+2){
textGeom(i).translateX(i).display();
}
‘for’ loop with textGeom
for (i = 0; i < 5; i++){
textGeom(i).translateX(i).display();
}
for (i = 0; i < 5; i++){
textGeom(2*i).translateX(i).display();
}
for (i = 0; i < 5; i++){
textGeom(2*i).translateX(2*i).display();
}
For loop with geometry
Use one cylinder and copy/move
g = cylinder(.5,.5);
for (i = 0;i < 5;i = i+1) {
g1 = g.clone();
g1.translateX(i).display();
}
Union with a base
For loop with geometry
Union with a base
base = cube(5,0.2,1).translateX(2.);
g = cylinder(.5,.5);
for (i = 0;i < 5;i = i+1) {
g1 = g.clone();
base = base.union(g1.translateX(i));
}
base.display();
Union ‘for’ loop
g = cube(.5,.5);
g1 = g.clone();
for (i = 0;i < 36;i++) {
g1.rotateZ(10);
g = g.union(g1);
}
g.display();
Union ‘for’ loop & difference
g = cube(.5,.5);
g1 = g.clone();
g2=cylinder(1,.45).rotateX(90);
for (i = 0;i < 36;i++) {
g1.rotateZ(10);
g = g.union(g1);
}
g=g2.difference(g)
g.display();
Lego model
Lego model: Step 1
g = cylinder(.5,.5);
g1 = g.clone();
for (i = 0;i < 3;i++)
{
g1.translate(2,0,0);
g = g.union(g1);
}
g.display();
Lego model: Step 2
g = cylinder(.5,.5);
g1 = g.clone();
for (i = 0;i < 3;i++)
{
g1.translate(2,0,0);
g = g.union(g1);
}
g3=g.clone().translate(0,0,2);
g=g.union(g3);
g.display();
Lego model: Step 3
g = cylinder(.5,.5);
g1 = g.clone();
base=cube(8,3,4).translate(3,-1.75,1);
for (i = 0;i < 3;i++)
{
g1.translate(2,0,0);
g = g.union(g1);
}
g3=g.clone().translate(0,0,2);
g=g.union(g3);
g=g.union(base);
g.display();
Lego model: Step 4
g = cylinder(.5,.5);
g1 = g.clone();
base=cube(8,3,4).translate(3,-1.75,1);
g4=cube(7,4,3).translate(3,-2.5,1);
base=base.difference(g4);
for (i = 0;i < 3;i++)
{
g1.translate(2,0,0);
g = g.union(g1);
}
g3=g.clone().translate(0,0,2);
g=g.union(g3);
g=g.union(base);
g.display();
Exercise (Ladder)
Length = 10, width = 0.25
(2 pieces, 1.25 apart)
1.5 length, 0.1 width and height
Exercise (Ladder)
Exercise
Radius = 0.1, height = 0.5
(centers on a circle of radius 0.8)
Radius = 1.0, height = 0.25
8 pins
Exercise
Modify your code to handle N pins
N = 3 pins
N = 6 pins
N = 8 pins
Exercise
setDefaultSegments(24);
R = 1.0;
H = 0.25;
A = cylinder(R,H);
r = 0.1;
h = 0.5;
s = 0.8;
pin =
cylinder(r,h).translateY(H/2+h/2).translateX(s);
N = 8; // number of pins
for (i = 0; i < N; i++) {
A = A.union(pin);
pin = pin.rotateY(360/N);
}
A.display();