it it is JAVA2D pgraphics, you may want to get accesss to the pixels[] array and just null them.

I would try this but I don't know why PGraphics.clear() doesn't work.

Julien
http://julienbayle.net

Maybe just define a brand new PGraphics object?

The following method should clear the PGraphic object 

1. void clearGraphics(PGraphics pg){
2.     pg.beginDraw();
3.     pg.background(pg.color(255, 0));  // transparent white
4.     pg.endDraw();
5. }

When using PGraphics objects all drawing commands must be done inside a beginDraw and endDraw. This method should not be called from within another pg.beginDraw() / pg.endDraw() because these commands must not be nested. In that case you only need line 3.

I used this technique in this applet.

actually, it doesn't.

Julien
http://julienbayle.net

Shame because it did for me, perhaps something has changed since I created the sketch.

I mean, that is only me or there is a bug in clearing a PGraphics ?

Have you checked the issues on github?

especially, the 2.0.3 version fixed that!