I'm having issues implementing  http://wiki.processing.org/w/Picking_with_a_color_buffer. I copy-pasted the code and got the following error:

I tried Googling but came up with nothing =/, any insights will be appreciated!

Thanks

1. void setup() {
2.   size(640, 360, P3D);
3.   fill(0);
4. }
5. 
   
6. void draw() {
7.   background(0);
8.   camera(0.0, 400.0, 0.0, // eyeX, eyeY, eyeZ
9.          0.0, 0.0, 0.0, // centerX, centerY, centerZ
10.          0.0, 0.0, 1.0); // upX, upY, upZ
11.   stroke(255,0,0);
12.   line(-100, 0, 0, 200, 0, 0);
13.   stroke(0,0,255);
14.   line(0, -100, 0, 0, 200, 0);
15.   stroke(0,255,0);
16.   line(0, 0, -100, 0, 0, 200);
17. }

It seems to tell me that the positive z axis is going downwards, even though the up vector is <0,0,1>. Why is that?

Thanks

I'm new to processing. I searched your past questions and couldn't find an answer.

I'm trying to make a 3-D object transparent. What I am looking for is to be able to see the contents inside of the sphere from the outside. I tried changing the alpha but all it seem to have done is fade the color of the sphere without showing me what's inside.

Thanks,