Problems rotating camera angle in OpenGL

Programming Questions

mrkzhu

Problems rotating camera angle in OpenGL

in Programming Questions • 5 months ago

I've created a sketch that plots different sized balls around the surface of a larger 3D sphere but I'm having trouble rotating the camera angle relative to the larger sphere.

I'm trying to compile this as javascript rather than java.

The Spherical part of the sketch is adapted from: http://blog.blprnt.com/blog/blprnt/processing-tutorial-spherical-coordinates

The camera angle code has been cut from the example here: http://processingjs.org/articles/RenderingModes.html

No luck with PeasyCam. I'm stuck as to how to proceed. I'm probably just doing something very stupid.

Any help would be most appreciated!

Here is my code:

import processing.opengl.*;

//import java.util.*;

//import java.math.BigDecimal;

Sphere mySphere;

String[] lines;

//float rotation = PI;

float ang = 0, ang2 = 0, ang3 = 0, ang4 = 0;

float px = 0, py = 0, pz = 0;

void setup()

{

size(500,500,OPENGL);

mySphere = new Sphere();

mySphere.init();

frameRate(50);

noStroke();

}

void draw()

{

mySphere.update();

mySphere.render();

println("in Camera");

beginCamera();

camera();

px = sin(radians(ang3)) * 170;

py = cos(radians(ang3)) * 300;

pz = sin(radians(ang4)) * 500;

translate(width/2 + px, height/2 + py, -700+pz);

rotateX(sin(radians(ang2)) * 120);

rotateY(sin(radians(ang2)) * 50);

rotateZ(sin(radians(ang2)) * 65);

ang2 += 0.01;

ang3 += 2.0;

ang4 += 0.75;

endCamera();

}

void mousePressed() {

mySphere.addSphereItem();

};

class Sphere {

float xPos = 250;

float yPos = 250;

float zPos = 250;

float radius = 50;

ArrayList items = new ArrayList();

public void Sphere() {

};

public void init() {

};

public void addSphereItem()

{

SphereItem si = new SphereItem();

si.parentSphere = this;

si.theta= random(PI*2);

si.phi= random(PI*2);

items.add(items.size(),si);

si.init();

println("addsphere");

}

public void update()

{

for (int i = 0; i < items.size(); i ++)

{

SphereItem si = (SphereItem) items.get(i);

si.update();

};

public void render() {

//Move to the center point of the sphere

translate(xPos, yPos, zPos);

//Mark our position in 3d space

pushMatrix();

//Render each SphereItem

for (int i = 0; i < items.size(); i ++)

{

SphereItem si = (SphereItem) items.get(i);

si.render();

};

popMatrix();

};

class SphereItem {

Sphere parentSphere;

float radius;

float theta;

float phi;

//Speed properties

float thetaSpeed = 0;

float phiSpeed = 0;

//Size

float itemSize = 5;

//String piDigits = "314159265358";

int piCounter = 0;

public void SphereItem()

{

};

public void init() {

itemSize = random(5);

thetaSpeed = 0.05;

phiSpeed = 0.06;

};

public void update()

{

theta += thetaSpeed;

phi += phiSpeed;

//println(piDigits.charAt(piCounter) - '0');

//itemSize = piDigits.charAt(piCounter) - '0';

//println(Float.parseFloat(piDigits.charAt(piCounter)));

//char piSize = piDigits.charAt(piCounter);

// println(x);

//String y = Character.toString(x);

//println(y);

String lines[] = loadStrings("pinumbers.txt");

//println(float(piSize));

itemSize = float(lines[piCounter])/3; // Set Item size as a x

piCounter= (piCounter + 1) % (lines.length - 1);

};

public void render() {

//Get the radius from the parent Sphere

float r = parentSphere.radius;

//Convert spherical coordinates into Cartesian coordinates

float x = cos(theta) * sin(phi) * r;

float y = sin(theta) * sin(phi) * r;

float z = cos(phi) * r;

//Mark our 3d space

pushMatrix();

//Move to the position of this item

translate(x,y,z);

//Set the fill colour

fill(0,0,0,150);

noStroke();

//Draw a circle

ellipse(0,0,itemSize,itemSize);

//Go back to our position in 3d space

popMatrix();

};

Replies(6)

Chrisir

Re: Problems rotating camera angle in OpenGL

5 months ago

maybe this helps...

you have to add the center to px and pz

//
//import processing.opengl.*;
//import java.util.*;
//import java.math.BigDecimal;
Sphere mySphere;
String[] lines;
//float rotation = PI;
float ang = 0, ang2 = 0, ang3 = 0, ang4 = 0;
float px = 0, py = 0, pz = 0;
void setup()
{
size(500, 500, P3D);
mySphere = new Sphere();
mySphere.init();
frameRate(50);
noStroke();
}
void draw()
{
background(111);
println("in Camera");
// beginCamera();
// camera();
px =250+ sin(radians(ang3)) * 470;
py =400; // 250+ cos(radians(ang3)) * 170;
pz =-250+ sin(radians(ang3)) * 170;
// translate(width/2 + px, height/2 + py, -700+pz);
// rotateX(sin(radians(ang2)) * 120);
// rotateY(sin(radians(ang2)) * 50);
// rotateZ(sin(radians(ang2)) * 65);
//ang2 += 0.01;
ang3 += 2.0;
//ang4 += 0.75;
// endCamera();
//camera(width/2.0, height/2.0, (height/2.0) / tan(PI*30.0 / 180.0), width/2.0, height/2.0, 0, 0, 1, 0). T
camera (px, py, pz,
250, 250, 250,
0, 1, 0);
// camera(width/2.0, height/2.0, (height/2.0) / tan(PI*30.0 / 180.0), width/2.0, height/2.0, 0, 0, 1, 0);
//
mySphere.update();
mySphere.render();
//
}
void mousePressed() {
mySphere.addSphereItem();
};
class Sphere {
float xPos = 250;
float yPos = 250;
float zPos = 250;
float radius = 50;
ArrayList items = new ArrayList();
public void Sphere() {
};
public void init() {
};
public void addSphereItem()
{
SphereItem si = new SphereItem();
si.parentSphere = this;
si.theta= random(PI*2);
si.phi= random(PI*2);
items.add(items.size(), si);
si.init();
println("addsphere");
}
public void update()
{
for (int i = 0; i < items.size(); i ++)
{
SphereItem si = (SphereItem) items.get(i);
si.update();
};
};
public void render() {
//Move to the center point of the sphere
translate(xPos, yPos, zPos);
//Mark our position in 3d space
pushMatrix();
//Render each SphereItem
for (int i = 0; i < items.size(); i ++)
{
SphereItem si = (SphereItem) items.get(i);
si.render();
};
popMatrix();
};
};
class SphereItem {
Sphere parentSphere;
float radius;
float theta;
float phi;
//Speed properties
float thetaSpeed = 0;
float phiSpeed = 0;
//Size
float itemSize = 5;
//String piDigits = "314159265358";
int piCounter = 0;
public void SphereItem()
{
};
public void init() {
itemSize = random(5);
thetaSpeed = 0.05;
phiSpeed = 0.06;
};
public void update()
{
theta += thetaSpeed;
phi += phiSpeed;
//println(piDigits.charAt(piCounter) - '0');
//itemSize = piDigits.charAt(piCounter) - '0';
//println(Float.parseFloat(piDigits.charAt(piCounter)));
//char piSize = piDigits.charAt(piCounter);
// println(x);
//String y = Character.toString(x);
//println(y);
String lines[] = loadStrings("pinumbers.txt");
//println(float(piSize));
itemSize = 33; // float(lines[piCounter])/3; // Set Item size as a x
piCounter++; // = (piCounter + 1) % (lines.length - 1);
};
public void render() {
//Get the radius from the parent Sphere
float r = parentSphere.radius;
//Convert spherical coordinates into Cartesian coordinates
float x = cos(theta) * sin(phi) * r;
float y = sin(theta) * sin(phi) * r;
float z = cos(phi) * r;
//Mark our 3d space
pushMatrix();
//Move to the position of this item
translate(x, y, z);
//Set the fill colour
fill(0, 0, 0, 150);
noStroke();
//Draw a circle
ellipse(0, 0, itemSize, itemSize);
//Go back to our position in 3d space
popMatrix();
};
};
//

Chrisir

Re: Problems rotating camera angle in OpenGL

5 months ago

it looks even cooler with spheres and lights

btw
no need for ; after }

//
//import processing.opengl.*;
//import java.util.*;
//import java.math.BigDecimal;
Sphere mySphere;
String[] lines;
//float rotation = PI;
float ang = 0, ang2 = 0, ang3 = 0, ang4 = 0;
float px = 0, py = 0, pz = 0;
void setup()
{
size(500, 500, P3D);
mySphere = new Sphere();
mySphere.init();
frameRate(50);
noStroke();
}
void draw()
{
background(111);
lights ();
ambientLight (110, 0, 0, 400, 250, 600);
pointLight (110, 0, 0, 400, 250, 100);
println("in Camera");
// beginCamera();
// camera();
px =250+ sin(radians(ang3)) * 470;
py =400; // 250+ cos(radians(ang3)) * 170;
pz =-250+ sin(radians(ang3)) * 170;
// translate(width/2 + px, height/2 + py, -700+pz);
// rotateX(sin(radians(ang2)) * 120);
// rotateY(sin(radians(ang2)) * 50);
// rotateZ(sin(radians(ang2)) * 65);
//ang2 += 0.01;
ang3 += 2.0;
//ang4 += 0.75;
// endCamera();
//camera(width/2.0, height/2.0, (height/2.0) / tan(PI*30.0 / 180.0), width/2.0, height/2.0, 0, 0, 1, 0). T
camera (px, py, pz,
250, 250, 250,
0, 1, 0);
// camera(width/2.0, height/2.0, (height/2.0) / tan(PI*30.0 / 180.0), width/2.0, height/2.0, 0, 0, 1, 0);
//
mySphere.update();
mySphere.render();
//
}
void mousePressed() {
mySphere.addSphereItem();
};
class Sphere {
float xPos = 250;
float yPos = 250;
float zPos = 250;
float radius = 50;
ArrayList items = new ArrayList();
public void Sphere() {
};
public void init() {
};
public void addSphereItem()
{
SphereItem si = new SphereItem();
si.parentSphere = this;
si.theta= random(PI*2);
si.phi= random(PI*2);
items.add(items.size(), si);
si.init();
println("addsphere");
}
public void update()
{
for (int i = 0; i < items.size(); i ++)
{
SphereItem si = (SphereItem) items.get(i);
si.update();
};
};
public void render() {
//Move to the center point of the sphere
translate(xPos, yPos, zPos);
//Mark our position in 3d space
pushMatrix();
//Render each SphereItem
for (int i = 0; i < items.size(); i ++)
{
SphereItem si = (SphereItem) items.get(i);
si.render();
};
popMatrix();
};
};
class SphereItem {
Sphere parentSphere;
float radius;
float theta;
float phi;
//Speed properties
float thetaSpeed = 0;
float phiSpeed = 0;
//Size
float itemSize = 5;
//String piDigits = "314159265358";
int piCounter = 0;
public void SphereItem()
{
};
public void init() {
itemSize = random(5);
thetaSpeed = 0.05;
phiSpeed = 0.06;
};
public void update()
{
theta += thetaSpeed;
phi += phiSpeed;
//println(piDigits.charAt(piCounter) - '0');
//itemSize = piDigits.charAt(piCounter) - '0';
//println(Float.parseFloat(piDigits.charAt(piCounter)));
//char piSize = piDigits.charAt(piCounter);
// println(x);
//String y = Character.toString(x);
//println(y);
String lines[] = loadStrings("pinumbers.txt");
//println(float(piSize));
itemSize = 33; // float(lines[piCounter])/3; // Set Item size as a x
piCounter++; // = (piCounter + 1) % (lines.length - 1);
};
public void render() {
//Get the radius from the parent Sphere
float r = parentSphere.radius;
//Convert spherical coordinates into Cartesian coordinates
float x = cos(theta) * sin(phi) * r;
float y = sin(theta) * sin(phi) * r;
float z = cos(phi) * r;
//Mark our 3d space
pushMatrix();
//Move to the position of this item
translate(x, y, z);
//Set the fill colour
//fill(0, 0, 0, 150);
fill(110, 0, 0, 255);
noStroke();
//Draw a circle
//ellipse(0, 0, itemSize, itemSize);
sphere (itemSize);
//Go back to our position in 3d space
popMatrix();
};
}
//

Chrisir

Re: Problems rotating camera angle in OpenGL

5 months ago

ah, I destroyed those lines

itemSize = 33; // float(lines[piCounter])/3; // Set Item size as a x
piCounter++; // = (piCounter + 1) % (lines.length - 1);

you need to fix them

mrkzhu

Re: Problems rotating camera angle in OpenGL

5 months ago

Thanks so much for your help!

I'm looking to keep the items small spheres I generate rather than wiping them with the background(). I.e. I want to be able to show all the points at once distributed across the sphere.

Can you think of a way to do this?

Chrisir

Re: Problems rotating camera angle in OpenGL

5 months ago

I'm looking to keep the items small spheres I generate rather than wiping them with the background().

hmmm-----

since we have a rotating camera you should use background() to clean the screen.
Otherwise the image gets destroyed because the camera moves.

I.e. I want to be able to show all the points at once distributed across the sphere.

I show a few points already, right?
So the points on the sphere are there as you wish. Do you agree?
You still should use background because of the camera movement.

Did you restore those lines :

itemSize = 33; // float(lines[piCounter])/3; // Set Item size as a x
piCounter++; // = (piCounter + 1) % (lines.length - 1);

mrkzhu

Re: Problems rotating camera angle in OpenGL

5 months ago

To clarify, what I'm looking to do is create a pattern of small spheres on the surface of a larger sphere. Here's an image of the static pattern of what I have in mind. I'd like to be able to rotate around this pattern i.e. all the points are visible at once.

The code to generate the regular pattern can be found here: https://github.com/kzhu/Pi-Sphere/tree/master/Sphere_Master

I wonder if I need to save all the individual points to an arraylist and render the entire array with when each frame is drawn? That way we can wipe the background and still maintain the sphere.