I've been trying to get this working for a while. For some reason it keeps giving problems. It compiles, but it doesn't do the trick. Any help? 

I'm trying to make it zoom and rotating around the object when pressed ENTER. 

3. public class Huisje{
4.   void draw(){
5.    translate(300, 0, 100); 
6.    noStroke();
7.    fill(100);
8.    box(50,20,10);  
9.   }
10. }
12. Huisje huis = new Huisje();
13. 
    
14. // Camera variables
15. float xPos = 100;
16. float yPos = -50;
17. float zPos = 100;
18. float rotation = 0;  
19. float radius = 50;  
20. 
    
21. // Zoom variables
22. float zoom = 0;
23. int s1;
24. int s2;
25. 
    
26. void setup(){
27.   size(400, 400, P3D);
28.   background(50);
29.   lights();
30. }
31.  
32.   
33. void draw(){
34.   cameraTurn(); 
35.   camera(  300 + xPos + zoom, 
36.            yPos + zoom, 
37.            100 + zPos + zoom, 
38.            300.0, 0, 100.0, 0.0, 1.0, 0.0);
39.   huis.draw();
40.   tekst();
41. }
42. 
    
43. void tekst(){
44.   if(mousePressed && (mouseX<140) && (130<mouseX) && (10<mouseY) && (mouseY<30)){
45.   zoom--;
46.   s1 = 155;
47.   redraw();
48.   } 
49.   
50.   else if(mousePressed && (mouseX< 120) && (110< mouseX) && (10<mouseY) && (mouseY<30)){
51.   zoom++;
52.   s2 = 155;
53.   redraw();
54.   }
55.   
56.   else{
57.   s1 = 0;
58.   s2 = 0;
59.   }
60.    
61.    camera();
62.    fill(100 + s1);
63.    textSize(20);
64.    text("-", 130, 20);
65.    fill(100 + s2); 
66.    textSize(20);
67.    text("+", 110, 20);  
68. }
69. 
    
70. void cameraTurn(){
71.   xPos = cos(radians(rotation)) * radius;
72.   zPos = sin(radians(rotation)) * radius;
73.   yPos = 0;
74.   while(keyPressed){
75.     if(key == ENTER){
76.   rotation++;
77.   redraw();
78.     }
79.    }
80. }