hello

a polygon perpendicular to z-axis is always not correctly rendered.
i can see the border lines but the polygon is not filled. polygons that are not perpendicular to z-axis are correctly rendered.

----

import processing.opengl.*;

float rotX;
float rotY;

void setup()
{
 size(200, 200, OPENGL);
 framerate(30);
}

void draw()
{
 background(51);
 fill(200);
 stroke(200);
 lights();

 pushMatrix();
 translate(width/2, height/2, 0);
 rotateX(rotY);
 rotateY(rotX);
 
 //a polygon perpendicular to z-axis
 beginShape(POLYGON);
 vertex(0.0, -50.0, -50.0);
 vertex(0.0, 50.0, 50.0);
 vertex(0.0,50.0, -50.0);
 endShape();
 
 // not perpendicular
 beginShape(POLYGON);
 vertex(-50.0, -50.0, 0.0);
 vertex(50.0, -50.0, 0.0);
 vertex(-50.0,50.0, 0.0);
 endShape();

 popMatrix();
}

void mouseDragged(){
 rotX += (mouseX - pmouseX) * 0.01;
 rotY += (mouseY - pmouseY) * 0.01;
}

just got a chance to confirm this.. looks like a bug. i'm guessing it's something to do with the clipping math, we'll look into it.

ah, that's helpful.. that means it's a problem in triangulation, not in just the clipping..

well, deodorizing contributed fixes are welcomed with open arms.