Now I'd been trying for months to realize my idea and also have posted so many threads and got a lot of help of you. but even though it wasn't possible to work it out..

It's still the same: a window that has got two frames (I think napplet makes sense).. the height of the upper frame should be fixed, the width should be the actual width..(frame.setResizable(true))

in the under frame there should be a 3-dimensional coordinate system.. Is this also possible with P3D or do I have to take OpenGL? There translation and rotation and zooming should be possible.. Can I make this like this or do I have to work with a matrix? (I would like to work with reflections and so on, too.. there I work with a matrix to calculate the things, but it isn't necessary to draw with a matrix, too. or not?)


AND THE MAIN PROBLEM:

When I have a 3d area.. How can I get the x,y and z coordinates. It's impossible to get the z or not? and do I have to project the whole thing to get the x,y-coordinates? or is there another possibilty?

if someone is interested in what I did and could help me to make it work better.. it would be nice..

Code:

import napplet.*;
NAppletManager nappletManager;

void setup() {  
  size(600, 600);  
  nappletManager = new NAppletManager(this);
  nappletManager.createNApplet("Menu",	0,0);
  nappletManager.createNApplet("Zeichnen",	0,100);
  
}


void draw() 
{  background(0); 
}

	





public class Menu extends NApplet {    
   
public void setup() {    size(600, 100);   
 }  
public void draw() {   
  background(0, 100, 0);   
  stroke(255);    fill(255);   
 }   


}

public class Zeichnen extends NApplet {    
   float rotx=.1, roty=.1;
int achl=600;
int a=100, offx=0, offy=0,offz=0;
int transx, transy, transz=-300;
int lastWidth, lastHeight;
int pfeil=6;
public void setup() {    size(600, 500,P3D);   
stroke(0);  
strokeWeight(1);  
strokeJoin(MITER);  
transx=width/2; 
transy=height/2; 
 }  
 
 
public void draw() {   
  background(255);
  pushMatrix();
translate(transx,transy,transz);  
rotateX(rotx);  
rotateY(roty);  
koordinatensystem();  
popMatrix();
 }   
 
 
 public void koordinatensystem(){  
strokeWeight(1.5);  
beginShape(LINES); 
  stroke(255,0,0); //z-achse rot  
  vertex(0,0,-achl);  
  vertex(0,0,achl);
  
 vertex(0,0,-achl);  // Pfeil 1
vertex(pfeil,0,-achl+pfeil); 
 vertex(0,0,-achl);
vertex(-pfeil,0,-achl+pfeil); 

 vertex(0,0,achl); //Pfeil 2
vertex(pfeil,0,achl-pfeil); 
 vertex(0,0,achl);
vertex(-pfeil,0,achl-pfeil); 

  stroke(0,255,0);  //y-achse grün
  vertex(0,-achl,0);  
  vertex(0,achl,0);  
     vertex(0,achl,0); // Pfeil 1
     vertex(0,achl-pfeil,pfeil); 
     vertex(0,achl,0);
     vertex(0,achl-pfeil,-pfeil); 
   
     vertex(0,-achl,0); // Pfeil 2
     vertex(pfeil,-achl+pfeil,0); 
     vertex(0,-achl,0);
     vertex(-pfeil,-achl+pfeil,0); 
     
     
     
  stroke(0,0,255);  //x-achse blau 
  vertex(-achl,0,0);  
  vertex(achl,0,0);  
  
  vertex(-achl,0,0); // Pfeil 1
  vertex(-achl+pfeil,0,pfeil);  
   vertex(-achl,0,0);
  vertex(-achl+pfeil,0,-pfeil);  
  
  vertex(achl,0,0); // Pfeil 2
   vertex(achl-pfeil,0,pfeil);
    vertex(achl,0,0);
   vertex(achl-pfeil,0,-pfeil);
endShape();}

public void mouseDragged() {  float factor = 0.01;  
if (key==CODED){ // Alt + Maus --> Rotation   
if(keyCode==ALT){     
  rotx += (pmouseY-mouseY) * factor;	
roty += (mouseX-pmouseX) * factor;    }    

if(keyCode==CONTROL){ // Ctrl + Maus --> Translation  
transx+=(mouseX-pmouseX);	transy+=(mouseY-pmouseY);    }  }}

public void keyPressed(){  
  if(key!=CODED){    
	if (key=='1'){	
	  rotx=0;	
	  roty=0;     
	  transx=width/2;	
	  transy=height/2;	
	  transz=-300;    
	}    
	
	if (key=='3'){	
	  rotx=0;	
	  roty=radians(-90);	
	  transx=width/2;	
	  transy=height/2;	
	  transz=-300;    
	 }    
	 
	if (key=='7'){	
	  rotx=radians(-90);	
	  roty=0;	
	  transx=width/2;	
	  transy=height/2;    
	  transz=-300;    
	}    
	}   
    
  if (key == CODED) {    
    if(keyCode==CONTROL){	
	if(key=='1'){	  
	  rotx=0;	  
	  roty=PI;	
	}	
    
	if(key=='3'){	  
	  rotx=0;	  
	  roty=radians(90);	
	}	
    
	if(key=='7'){	  
	  rotx=radians(90);	  
	  roty=0;	
	}    
    }  
  }
}



}