moving object with 3D view

Programming Questions

sylvain.u..

in Programming Questions • 1 year ago

Hi everybody.

I am currently trying to write a script to draw an abstract stairs.

I am using rectangle as a step, this rectangle is moving in x or y.

Every step, the rectangle is tranlslated in z to climb.

It works fine when I look from the top ( example 01), but when i use something like peasy cam to move around the stairs, the x,y,z system seems to be reboot for every view...

In the other hand, failed to replace the move with a translate ( example 02) ... any clue do use translate correctly ?

Thanks !

EXAMPLE 01 :

int x = 100; // position en x de la marche
int y = 100; // position en y de la marche
int R = 20; // dimensions de la marche
int m = R; //mouvement
int mx; // mouvement en X
int my; // mouvement en Y
int cm = 10; //contremarche
int mz; // mouvement en Z
// ...
void setup() {
size (600, 600, P3D);
background(0);
frameRate(5);
}
void draw () {
climb();
display();
//bounce();
}
void climb () {
mx = m*round(random(0, 1));
x = x + mx;
if (mx > 0) {
my = 0;
}
else {
my = m;
}
y = y + my;
}
void display() {
translate (0, 0, mz);
mz = mz+cm;
rect (x, y, R, R);
}

EXAMPLE 02

int x = 200; // position en x de la marche
int y = 200; // position en y de la marche
int R = 20; // dimensions de la marche
int m = R; //mouvement
int mx; // mouvement en X
int my; // mouvement en Y
int cm = 10; //contremarche
int mz; // mouvement en Z
// ...
void setup() {
size (600, 600, P3D);
background(0);
frameRate(5);
}
void draw () {
climb();
display();
//bounce();
}
void climb () {
mx = m*round(random(0, 1));
if (mx > 0) {
my = 0;
}
else {
my = m;
}
pushMatrix();
translate (mx,0,0);
translate (0,my,0);
translate (0,0,mz);
mz = mz+cm;
rect (x, y, R, R);
popMatrix();
}
void display() {
}

Replies(5)

benja

Re: moving object with 3D view

1 year ago

hey,

i don't see anything with peasy-cam here, so i don't really understand the issue.
Maybe the problem is, that you don't draw the whole stairs on every frame. So if you would rotate the view, while running the sketch, that would only have effect for the rectangles which you draw after that.

Then in your second example, you don't really increase the values wich you use for translate in x- and y-direction.
I would recommend, to use only one translate()-call and not mix translate() with x- and y-coordinates for rect().

translate(x, y, z);
rect(0,0, w, h);

sylvain.u..

Re: moving object with 3D view

1 year ago

i don't see anything with peasy-cam here, so i don't really understand the issue

Sorry, here is a simplified example with peasy cam

import peasy.*;
PeasyCam cam;
int x = 0;
int y = 0;
int m = 40;
int mx;
int my;
int mz;
void setup() {
size (600, 600, P3D);
background(0);
frameRate(1);
cam = new PeasyCam(this, 500);
cam.setMinimumDistance(1000);
cam.setMaximumDistance(500);
}
void draw() {
mx = m*round(random(0, 1))+mx ;
if (mx >0) {
my = 0 ;
}
else {
my = m + my;
}
mz = mz +10;
pushMatrix();
translate(mx, my, mz);
rect(x, y, 40, 40);
popMatrix();
}

Maybe the problem is, that you don't draw the whole stairs on every frame. So if you would rotate the view, while running the sketch, that would only have effect for the rectangles which you draw after that

Exactly !! I draw one step at every frame. Should I work on void setup only ? Or place the background on void draw and generate the current and previous step at every frame ?

I also solve the translate issue (works for x, but not for y... still working on it)

edit : i find why y didn't work, mx is always > 0...

Thank you for your answer.

benja

Re: moving object with 3D view

1 year ago

yep, if i understood correctly what you want then you increase x or y on every frame randomly.
try:

if(random(0, 1) > 0.5){
mx += m;
}else{
my += m;
}

If you want to move around the stairs, then yes you have to draw them all in every frame. You could create the coordinates of all rectangles once inside of setup() and then display them all inside of draw().

sylvain.u..

Re: moving object with 3D view

1 year ago

The random component works fine !

I'm looking for the second thing.

sylvain.u..

Re: moving object with 3D view

1 year ago

I think this kind of thing could work :

// DECLARE
import peasy.*;
PeasyCam cam;
ArrayList ballCollection;
void setup () {
size (600, 600,P3D);
cam = new PeasyCam(this, 1000);
cam.setMinimumDistance(300);
cam.setMaximumDistance(1000);
smooth();
// INITIALIZE
ballCollection = new ArrayList();
// for (int i = 0; i < 100; i++) {
// Ball myBall = new Ball (random(0, width), random (0, 200));
// ballCollection.add(myBall);
//}
}
void draw() {
background(0);
Ball myBall = new Ball (300,300);
ballCollection.add(myBall);
// CALL FUNCTIONALITY
for (int i = 0; i < ballCollection.size(); i++) {
Ball mb = (Ball) ballCollection.get(i);
mb.run();
}
}
class Ball {
// GLOBAL VARIABLES
float x = 0;
float y = 0;
float speedX = 7;
float speedY = 2;
// CONSTRUCTOR
Ball(float _x, float _y) {
x = _x;
y = _y;
}
//FUNCTIONS
void run() {
display();
move();
bounce();
gravity();
}
void gravity() {
speedY = speedY + 0.8;
}
void bounce() {
if (x > width) {
speedX = speedX * -1;
}
if (x < 0) {
speedX = speedX * -1;
}
if (y > height) {
speedY = speedY * -1;
}
if (y < 0) {
speedY = speedY * -1;
}
}
void move() {
x = x + speedX;
y = y + speedY;
}
void display() {
ellipse(x, y, 20, 20);
}
}

(found in Jose Sanchez tutorial n°09)

Top Reply