I quickly tested on 2.0a1, and seems to work with something like this:

That is exactly what I have but I move the pgl.end() to end of the drawing now I get the blending working but the sketch is not smooth as in P5 v1.5.1 I try using hint( ENABLE_OPENGL_4X_SMOOTH ); but no difference, any ideas?

For the next alpha (which will be 3, alpha 2 came out just today, but doesn't bring any changes related to OpenGL, most of the work was on the video library and 64 bits support), I will focus on the P3D (desktop/android). 

trying to use this on the latest processing 2.0b3, but i get the error

hey guys i'm porting over some code from processing 1  -> 2 and running into a funny additive blending issue ...

1. //in my main draw i'm calling
2. 
   
3.   PGraphicsOpenGL pgl = (PGraphicsOpenGL) g;
4.   GL2 gl = pgl.beginPGL().gl.getGL2();
5. 
   
6.   gl.glDisable(GL2.GL_DEPTH_TEST);
7.   gl.glEnable(GL2.GL_BLEND);
8.   gl.glBlendFunc(GL2.GL_SRC_ALPHA, GL2.GL_ONE);
9. 
   
10.  //...
11. 
    
12.   //and then drawing a particle system that involves a bunch of
13. void render() {
14. 
    
15.     pushMatrix();
16.     translate(loc.x, loc.y, loc.z);
17. 
    
18.     noStroke();
19. 
    
20.     beginShape(TRIANGLE_FAN);
21.     fill(255, 255, 255, 50);
22.     vertex(0, 0);
23.     fill(171, 124, 78, 0);
24.     for (float j=0; j<=TWO_PI; j+=TWO_PI/12) {
25.       vertex( 0+lineWidth*cos(j), 0+lineWidth*sin(j) );
26.     }
27.     endShape();
28. 
    
29.     popMatrix();
30. }
31. 
    
32. //...
33. 
    
34. //and then ending the main draw with
35. pgl.endPGL();

ok, my guess is that this is an OpenGL zNear and zFar clipping plane issue in the processing code... http://www.opengl.org/archives/resources/faq/technical/depthbuffer.htm   especially because when i just translate my particles in void render using

1. translate(loc.x, loc.y);

i don't see the image border artifact in the image above.  i'm guessing this may fit into the " this is not supported, in the sense that if you get weird problems with a GL-based sketch that uses this method, you're on your own" category... a hackish work around is to fake the 3D by still calculating z values, but instead of translating in z, just have that z value affect the visuals (i.e. diameter * z )...

also, is anyone else getting this weird image noise on the start of their sketch?  seems to be a visual leftover from the last time the sketch was exited.  didn't get it in 2.0b6, but i am getting it in 2.0b7...

For the blending problem, you should be able to replace the opengl calls with blendMode(ADD). This is a new function added in Processing which sets screen blending with OpenGL under P2D and P3D for most of the blending modes supported by blend.

Hi,