proscene, pixel picking

gennarose..

in Contributed Library Questions • 2 years ago

hello All,

I'm trying to use an auxiliary buffer to draw objects that I don't want to display in the main scene
the reason for this is to be able to pick objects like lines for which would be very expensive to draw boxes
also I want to be able to pick the lines at any point along their length and not just in the middle (for instance if using proscene interactiveFrame and placing a point in the middle)

I've seen the example here, where a Scene is instantiated using an auxiliary buffer and then in the main draw-method it uses buffer.beginDraw and scene.BeginDraw etc. etc.
but this is doing the opposite of what I want since it is drawing and displaying everything in the auxiliary buffer....

I attach here the code, the picking for the lines it is a simple "pixel based picking" (original code here) so that each lines is draw in both the main scene and in the auxiliary buffer. In the auxiliary buffer each line is drawn with a different color so that it is easy to pick them. In the main scene the lines are just drawn in black. This works fine with any cam I tried so far as long as the camera of the buffer is synchronized with that of the main scene (i.e. cam.getState().apply(buffer))

any solutions using proscene and some HUD with controlP5 (see the code below) ?

import remixlab.proscene.*;
import controlP5.*;
import processing.opengl.*;
ControlP5 controlP5;
Scene scene;
PGraphics backBuffer;
PGraphics backBuffer2;
PGraphics3D backBuffer3D;
ArrayList<box> boxes;
ArrayList<line3D> myLines;
PApplet aa;
void setup()
{
size(500, 500, OPENGL);
smooth();
backBuffer = createGraphics(width, height, P3D);
backBuffer3D=(PGraphics3D)this.g;
backBuffer2 = createGraphics(width, height, P3D);
scene = new Scene(this);
// press 'f' to display frame selection hints
scene.setShortcut('f', Scene.KeyboardAction.DRAW_FRAME_SELECTION_HINT);
controlP5 = new ControlP5(this);
controlP5.addButton("button", 10, 100, 60, 80, 20).setId(1);
controlP5.addButton("buttonValue", 4, 100, 90, 80, 20).setId(2);
controlP5.setAutoDraw(false);
boxes = new ArrayList<box>();
for (int i = 0; i < 50; i++)
{
box obj = new box(15f, 15f, 15f, i);
boxes.add(obj);
}
myLines= new ArrayList<line3D>();
for (int i = 0; i < boxes.size()-1; i++)
{
line3D obj = new line3D(boxes.get(i).mFrame.position(), boxes.get(i+1).mFrame.position(), i);
myLines.add(obj);
}
}
void draw()
{
background(255);
stroke(0);
strokeWeight(2);
Iterator it = boxes.iterator();
while (it.hasNext ())
{
box obj = (box)it.next();
pushMatrix();
obj.display();
popMatrix();
}
for (int i = 0; i < boxes.size()-1; i++)
{
myLines.get(i).display(g, boxes.get(i).mFrame.position(), boxes.get(i+1).mFrame.position());
}
backBuffer.beginDraw();
for (int i = 0; i < boxes.size()-1; i++)
{
myLines.get(i).drawBuffer(backBuffer);
}
backBuffer.endDraw();
backBuffer.applyMatrix(backBuffer3D.camera);
//HUD to be implemented
//drawGUI();
}
void drawGUI()
{
controlP5.draw();
}
// test your frame rate, mine is ~40fps
void keyPressed()
{
if (key == 'x') println(frameRate);
}
void mouseClicked()
{
// get the pixel color under the mouse
color pick = backBuffer.get(mouseX, mouseY);
// get object id
int id = getId(pick);
print(id);
// if id > 0 (background id = -1)
if (id >= 0 & id< myLines.size())
{
// change the line color
myLines.get(id).changeColor();
}
}
// color -2 gives 0, etc.
int getId(color c)
{
return -(c + 2);
}
// id 0 gives color -2, etc.
color getColor(int id)
{
return -(id + 2);
}
////////////////////////////////////////////////////////
class box
{
public float mWidth,mHeight,mDepth;
public PVector mPosition;
public InteractiveFrame mFrame;
public int ID;
public boolean selected;
box(float w, float h, float d, int ID)
{
mWidth = w; mHeight = h;mDepth = d;
this.ID=ID;
float low = -100;float high = 100;
mPosition = new PVector(random(low, high), random(low, high), random(low, high));
mFrame = new InteractiveFrame(scene);mFrame.setPosition(mPosition);
}
void display()
{
// No need to call translationbackBuffer.translate(mPosition.x, mPosition.y, mPosition.z);
// Frame.applyTransformation does it.
mFrame.applyTransformation();
isSelected();
if (selected==true)
{
g.fill(255, 0, 0);
}
else
{
g.fill(200);
}
g.stroke(0);
g.box(mWidth, mHeight, mDepth);
}
public void isSelected()
{
if (mFrame.grabsMouse())
{
selected=true;
}
else
{
selected=false;
}
}
}
////////////////////////////////////////////////////////
class line3D
{
// variables
int id; // id
color c; // color (in scene, not buffer)
public PVector p0;
public PVector p1;
// constructor
public line3D(PVector p0, PVector p1, int id)
{
this.id=id;this.p0=p0;
this.p1=p1;c = color(0, 0, 0);
}
// make the color change
public void changeColor()
{
int r = (int)red(c);int g = (int)green(c);
int b = (int)blue(c);c = color(255-c, 0, 0);
}
// display the line on screen
public void display(PGraphics ecran,PVector p0,PVector p1)
{
this.p0=p0;this.p1=p1;
ecran.stroke(c);drawLine(ecran);
}
// draw the line in the buffer
public void drawBuffer(PGraphics buffer)
{
color idColor = getColor(id);buffer.strokeWeight(10);
buffer.stroke(idColor);drawLine(buffer);
}
private void drawLine(PGraphics g)
{
g.line(p0.x, p0.y, p0.z, p1.x, p1.y, p1.z);
}
}

Replies(1)

chicoatomo

Re: proscene, pixel picking

8 months ago

Hello

The kind of picking that you want to do is implemented in this useful Picking library (by antiplastick)

This library is developed for processing 1.5.1 and a few days ago Massimo and I have converted to work with Processing v2.0b7. It could be useful for you.

Picking library for processing 2.0.b7

I'm using also the fantastic proscene library (thanks to Jean Pierre Charalambos ) but I've problems with the picking library.

Someone can make picking with proscene?

thanks in advance.

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