Adding random rotation to a program which clusters/organises randomly distributed objects

Programming Questions

adam15390

Adding random rotation to a program which clusters/organises randomly distributed objects

in Programming Questions • 11 months ago

Hi,

I am currently trying to get to grips with processing as part of my dissertation for my Masters Degree. I am hoping to write a piece of code which will be able to randomly distribute houses (represented by rectangles) within a given area, with a minimum distance between each house (i.e no overlapping), and possibly arranged around a road structure (probably just represented by some lines- but this part is only if i have time/is even possible). Then use genetic algorithm to test the fitness function (based around the number of houses achieved) to reach the optimal solution in terms of density.

I have been looking at a number of examples for the initial part of my study (most of which involve circles):

https://forum.processing.org/topic/help-random-distribution-of-non-overlapping-circles

// i was interested in the way that the answer to this problem tests for overlapping

http://alignedleft.com/projects/2008/square_spriral_collision_test3/applet/square_spriral_collision_test3.pde

// i have mainly been looking at this one - though i think a few of the details (the square spiral, the mouse/keyboard inputs etc) are unnecessary for what i am trying to achieve. I just cant figure out what to take out!

http://paulbourke.net/texture_colour/randomtile/

// this one seems closest to what i am looking for but i don't understand it at all

Where I am currently at:

// This is very basic, but it reflects my competency levels! It simply randomly generates rectangles within a specified area. I would like to add:

1. A random rotation factor for the rectangles

2. The ability to calculate and avoid collisions (though i think this requires the rectangles to be objects??)

3. The ability to calculate collisions with the boundary line (as currently i am just specifying a field within which to place the rectangles)

void setup(){
size(1000,1000);
}
int amount = 40;
float w = 500;
float h = 250;
float lhs = ((w/2)-width);
float rhs = lhs + w;
float t = (h/2)+h;
float b = t + h;
void draw(){
background(0);
stroke(255);
noFill();
rect(((width-w)/2),((height-h)/2),w,h);
fill(30,60);
for (int i=0; i < amount; i++){
float x = random(lhs, rhs-20);
float y = random(t, b-40);
rect(x,y,20,40);
}
noLoop();
}

// This example is basically just a very simple tweak of the 2nd link above, i am struggling with it

int numHouses = 20;
int spacing = 1;
int minSep = 0;
int maxSep = 0;
Object[] objects = new Object[1];
void setup(){
size(1000,1000);
objects[0] = new Object(0);
for(int i= 1; i <numHouses; i++){
Object objectInstance = new Object(i);
objects = (Object[]) append(objects, objectInstance);
}
}
void draw()
{
background(255);
pushMatrix();
translate(width/2, height/2);
for(int i=0; i <objects.length; i++){
objects[i].display();
}
popMatrix();
}
class Object {
int id;
float x;
float y;
int w;
int h;
int spiralPhase = 1;
float spiralMaxDistance = 1;
Object(int _id){
id = _id;
x = int(random(-width/2, width/2));
y = int(random(-height/2, height/2));
w = 20;
h = 40;
}
void display() {
pushMatrix();
translate(x, y);
fill(150, 50);
rect(0, 0, w,h);
fill(0);
text(id, 5, 25);
popMatrix();
}
void resetObject() {
x = 0;
y = 0;
spiralPhase = 1;
spiralMaxDistance = 1;
}
void moveInSpiral() {
switch(spiralPhase) {
case 1:
x++; //Move right
if(x >= spiralMaxDistance) {
spiralPhase = 2; //Switch to next phase
}
break;
case 2:
y++; //Move down
if(y >= spiralMaxDistance) {
spiralPhase = 3; //Switch to next phase
}
break;
case 3:
x--; //Move left
if(abs(x) >= spiralMaxDistance) {
spiralPhase = 4; //Switch to next phase
}
break;
case 4:
y--; //Move up
if(abs(y) >= spiralMaxDistance) {
spiralPhase = 1; //Switch to next phase
spiralMaxDistance++;
}
break;
}
}
void newRandomPositionAndSize() {
x = int(random(-width/2, width/2));
y = int(random(-height/2, height/2));
}
}
//
// Checks for collisions between any two objects
//
boolean isCollision(Object object1, Object object2) {
float minDistance = object1.w + object2.w + spacing;
float actualDistance = dist(object1.x, object1.y, object2.x, object2.y);
boolean isCollision;
if (actualDistance < minDistance) {
isCollision = true;
}
else {
isCollision = false;
}
return isCollision;
}
void clusterObjects() {
//First reset all positions to 0,0
for(int i = 0; i < objects.length; i++) {
objects[i].resetObject();
}
//Then resolve collisions --- test current object (i) against all prior objects (j)
//i starts at 1, though, in order to skip over the first object, which will just remain at 0,0
for(int i = 1; i < objects.length; i++) {
boolean collisionsOccurring = true;
int collisionTally = 0;
while(collisionsOccurring) {
for(int j = 0; j < i; j++) { //Test i vs. all prior j's
if(isCollision(objects[i], objects[j])) {
collisionTally++; //If there is a collision, then increment the tally.
}
}
if(collisionTally > 0) { //If any collisions happened,
objects[i].moveInSpiral(); //then move object i to a new position
collisionTally = 0; //and start the loop over again.
}
else { //But if no collsions happened,
collisionsOccurring = false; //then this loop is done, and we can move on to the next object i.
}
}
}
}
void mousePressed() {
clusterObjects();
}
void keyPressed() {
if (key == 'r') { //Randomize positions and sizes
for (int i = 0; i < objects.length; i++) {
objects[i].newRandomPositionAndSize();
}
}
else if (key == ']') { //Increase spacing
spacing++;
clusterObjects();
}
else if (key == '[') { //Decrease spacing
spacing--;
clusterObjects();
}
else if (key == '+' || key == '=') { //Create a new object
numHouses++;
Object objectInstance = new Object(objects.length);
objects = (Object[]) append(objects, objectInstance);
}
else if (key == '-' || key == '_') { //Remove the newest object
if(numHouses > 0) {
numHouses--;
objects = (Object[]) shorten(objects);
}
}
}

Apologies for the length of this question, but any help/guidance would be very greatly appreciated

Many thanks,

Adam

Replies(2)

PhiLho

Re: Adding random rotation to a program which clusters/organises randomly distributed objects

11 months ago

I have no time to do a detailed answer right now, and I am not sure I can contribute something significant, but I appreciate the link to the Paul Burke article. I might give it a try.

Just a generic advice, though: don't call a class "Object".
This is the name of a fundamental class in Java (all classes extend Object) and using such name can lead to confusion and perhaps to some subtle bugs...

adam15390

Re: Re: Adding random rotation to a program which clusters/organises randomly distributed objects

11 months ago

Thanks for the advice

. I have since come up with a couple of other attempts:

//This one generates a load of rectangles all rotated by a random amount. what i need is to define the area within which they are placed to the area of the rectangle in the center:

void setup(){
size(1000,1000);
}
int amount = 400; //Number of Rectangles
float w = 500; //large rectangle width
float h = 250; //* height
float lhs = ((w/2)-width); //left hand edge of large rectangle
float rhs = lhs + w; //right hand edge of large rectangle
float t = (h/2)+h; //top of large rectangle
float b = t + h; //bottom of large rectangle
void draw(){
background(0);
stroke(255);
noFill();
rect(((width-w)/2),((height-h)/2),w,h); //large rectangle
fill(100,40);
for (int i=0; i < amount; i++){
float x = random(lhs, rhs-20); //was used to limit x coordinate within large rectangle area - doesnt work when rotation is applied!
float y = random(t, b-40); //same as above but for y
pushMatrix(); //not sure if this is the right way to use this
translate(width,height); //seemed to cluster the rectangles more centrally
rotate(PI*random(10)); //random rotation factor?
rect(x,y,20,40); //rectangle unit size
popMatrix();
}
noLoop();
}

//This one creates rectangle objects (as i think i need them to be objects in order to calculate collisions), but they are all rotated by the same random value, i need them to rotate by their own individual random values:

int amount =40;
House ho;
void setup(){
size(1000,1000);
smooth();
ho = new House();
ho.w = 20;
ho.l = 40;
ho.x = random(width/4);
ho.y = random(height/4);
ho.r = random(10);
}
void draw(){
background(0);
stroke(255);
fill(100,40);
translate(width/2, height/2);
for (int i=0; i<amount; i++){
rotate(PI/ho.r);
rect(ho.x,ho.y,ho.w,ho.l);
}
}
class House{
float x, y;
float w, l, r;
}

Any ideas on how to combine the two? and then limit the field to the area of the large rectangle?

Thanks in advance

Adam

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