Hello,

I used the picking with projection code from Tom Carden for creating buttons in 3D. Unfortunately, I discover now, after some changes, that for each button I create there is a "ghost-button".

I asked myself if it could be a wrong use of pushMatrix();/ popMatrix();, but I don't have enought experience with processing to find the fault myself..

I would be very grateful for some help.
Thank you very much,
David  



code:

import processing.opengl.*;
import javax.media.opengl.GL;


PVector camPosition;
PVector camLookAt;
float camHeight = -6;

Vector triangles_01 = new Vector();

float currentAngle = -1.5;
int picked_01;


class Vector3d {

float x,y,z;

Vector3d(float x, float y, float z) {
  this.x = x;
  this.y = y;
  this.z = z;
}



Vector3d project() {
  return new Vector3d(screenX(x,y,z),screenY(x,y,z),screenZ(x,y,z));
}

}



////////////////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////



class Triangle_01 implements Comparable {

Vector3d a,b,c;
Vector3d pa,pb,pc;
boolean clicked = false;



Triangle_01(Vector3d v1, Vector3d v2, Vector3d v3)
{
  this.a = v1;
  this.b = v2;
  this.c = v3;
}

void project() {
  pa = a.project();
  pb = b.project();
  pc = c.project();
}
 
boolean mouseOver() {
  Polygon p = new Polygon( new int [] { (int)pa.x, (int)pb.x, (int)pc.x }, new int [] { (int)pa.y, (int)pb.y, (int)pc.y }, 3);
  return p.inside(mouseX,mouseY);
}

int compareTo(Object other) {
  // compare average depth
  float d1 = pa.z+pb.z+pc.z;
  Triangle_01 t2 = (Triangle_01)other;
  float d2 = t2.pa.z+t2.pb.z+t2.pc.z;
  if (d1>d2) {
    return 1;
  }
  else if (d1==d2) {
    return 0;
  }
  else {
    return -1;
  }
}


}




////////////////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////


int getPicked_01() {
int picked_01 = -1;
if (mouseX >= 0 && mouseX < width && mouseY >= 0 && mouseY < height) {
  for (int i = 0; i < triangles_01.size(); i++) {
    Triangle_01 t = (Triangle_01)triangles_01.get(i);
    t.project();
  }
  Collections.sort(triangles_01);
  for (int i = 0; i < triangles_01.size(); i++) {
    Triangle_01 t = (Triangle_01)triangles_01.get(i);
    if(t.mouseOver()) {
      picked_01 = i;
      break;
    }
  }
}
return picked_01;
}


////////////////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////

void setup() {
size(1000, 562,OPENGL);


camPosition = new PVector( -26.0, camHeight, 12.71);
camLookAt = new PVector(camPosition.x + 100*cos(currentAngle), camPosition.y, camPosition.z + 100*sin(currentAngle));


{
  Vector3d v1 = new Vector3d(-25.5,-5.0,10.3); //unten
  Vector3d v2 = new Vector3d(-26.3,-5.75,12.05); //Seite rechts
  Vector3d v3 = new Vector3d(-26.0,-5.0,12.85); //Spitze
  Vector3d v4 = new Vector3d(-25.3,-4.2,12.2); //Seite links
 
 triangles_01.add(new Triangle_01(v1, v2, v3));
 triangles_01.add(new Triangle_01(v1, v3, v4));
}


noStroke();
}









void draw() {
background(255);


beginCamera();
  camera(camPosition.x, camPosition.y, camPosition.z,
         camLookAt.x, camLookAt.y, camLookAt.z,
         0, 1, 0);
 
  //for perspective
  float aspect = float(width)/float(height);
  perspective(1.235, aspect, .1, 500);
endCamera();





 pushMatrix();

picked_01 = getPicked_01();



{
beginShape(TRIANGLES);
noStroke();
for (int i = 0; i < triangles_01.size(); i++) {
  Triangle_01 t = (Triangle_01)triangles_01.get(i);
  if (i == picked_01) {
    fill(#ff0000);
  }
  else {
    fill(#050505);
  }
 
  vertex(t.a.x,t.a.y,t.a.z);
  vertex(t.b.x,t.b.y,t.b.z);
  vertex(t.c.x,t.c.y,t.c.z);
 
   if (t.clicked) {
     link("
     
     
     //your link
     
     
     ");
     t.clicked = false;
     }
   
}
endShape();  
}

popMatrix();

}


void mouseReleased() {
if (picked_01 >= 0 && picked_01 < triangles_01.size()) {
  Triangle_01 t = (Triangle_01)triangles_01.get(picked_01);
  t.clicked = !t.clicked;
}
}