I'm attempting to create an animation in Processing (v 2.0b7 on a Mac) using a PGraphics object and saving the frames to png files. The motion works perfectly and the files save fine, but I need to clear the graphic between each frame and since I am using transparency, I can't simply set a new background. From the online documentation, including the Javadoc for the PGraphics class, it would appear that calling the clear() method should do exactly what I want. However, when I include this call I get a compile error with the message in the title of this post.

Any ideas what I'm doing wrong, or if there's a better way of doing this? I'll paste in a portion of my code below to show what I'm doing ...

Many thanks

Nick

2. PGraphics pg;
3. 
   
4. float originX, origin Y, a, b;
5. 
   
6. void setup() {
7.   size(600, 600, P3D);
8.   pg = createGraphics(600, 600, P3D);
9.   smooth();
10.   frameRate(16);
11.   
12.   // code to set up position, rotation etc ...
13.   
14. }
15. 
    
16. void pgDrawLoop(float originX, float originY, float rotationX, float rotationY) {
17.   pg.beginDraw();
18.   pg.pushMatrix();
19.   pg.translate(originX, originY);
20.   pg.pushMatrix();
21.   pg.stroke(217, 67, 100);
22.   pg.strokeWeight(3);
23.   pg.noFill();
24.   pg.rotateX(rotationX);
25.   pg.rotateY(rotationY);
26.   pg.translate(0, 0);
27.   pg.beginShape();
28.   pg.vertex(0, -200, 0);
29.   pg.bezierVertex(160, -200, 200, -160, 200, 0);
30.   pg.bezierVertex(200, 160, 160, 200, 0, 200);
31.   pg.bezierVertex(-160, 200, -200, 160, -200, 0);
32.   pg.bezierVertex(-200, -160, -160, -200, 0, -200);
33.   pg.endShape();
34.   pg.popMatrix();
35.   pg.rotateX(-rotationX);
36.   pg.rotateY(-rotationY);
37.   pg.popMatrix();
38.   pg.endDraw();
39. }
40. 
    
41. 
    
42. void draw() {
43. 
    
44. if(frameCount > 400) {
45. exit();
46. }
48. // Code to calculate position and rotation here ...
50. pg.clear();
51. pg.background(0,0,0,0);
52. pgDrawLoop(originX1, originY1, a, b);
53. image(pg, 0, 0);
54. }