Hi,

I am a new user of processing and I already have a big dilemma.

I try to draw a simple coordinate basis using this code:

1. import processing.opengl.*;
         
   void setup() {
     size(600, 600, OPENGL);
     smooth();
   }
   
   void draw() {
     background(0);
     strokeWeight(5);
     translate(300,300,0);
     drawAxes();
   }
   
   void drawAxes() {
        
     pushMatrix();
     rotateX(PI/6);
     rotateZ(PI/6);
     stroke(255, 0, 0);
     line(-10, 0, 0, 50, 0, 0);      
     stroke(0, 255, 0);
     line(0, -10, 0, 0, 50, 0);    
     stroke(0, 0, 255);
     line(0, 0, -10, 0, 0, 50);
     popMatrix();
   }

After a quick look I noticed that the 3D graphic environment uses the left-hand rule. I mean that in classical 3D geometry and math, to construct an orthonormal basis, we use the right-hand rule: {x = (1, 0, 0), y = (0, 1, 0), z = (0, 0, 1)}, so z = crossproduct(x,y); y = crossproduct(z,x) and x = crossproduct(y,z);

In processing it seems that the left-hand is used then so z = -crossproduct(x,y) = crossproduct(y,x); (In the code I gave, the blue vecteur (Z), is pointing up while it should be down with the rigth hand rule).

Am I correct? If yes, is there any possibility to have a 3D environement which use the right-hand rule? I don't realy want to use the scale function.

Thanks a lot.

Bertrand