Processing can export to DXF which can be read by Autocad which can then save as DWG?

Yes I know. But how do I export in DXF? 

http://www.processing.org/reference/libraries/


2nd line, 2nd column

that's the code

Try it yourself and see what happens.

it doesn't work together with the code converting to dxf. please HELP 

What leads you to the conclusion that it doesn't work?

Two sidenotes. Your code contains extra endShape()'s, which you might wanna remove. You are plotting thousands (!) of points just to make a curve that you could probably make much more efficiently with a few bezierpoints as well. Of course this will also impact the file size of the exported dxf (aka your code will produce a huge file).

says beginRaw() and endRaw() are not available with this renederer

Use the P3D renderer.

And also it doesn't seem to save the dxf file.

Just put everything in setup() and between those two calls, then exit().

u mean all the code?

Yes, except size() of course.

You don't really need a draw() loop if you just wanna save the complete drawing to a dxf once.

Also, it might be smart to start small (for example with just the background and four line() calls) and once you got that working include more shapes. Incremental development is the key to succes.

Like this...

Adapted Code

1. import processing.dxf.*;
2.  
3. void setup() {
4.   size(500, 500, P3D);
5.  
6.   beginRaw(DXF, "drawing.dxf");
7.  
8.   line (250, 0, 250, 500);
9.   line (0, 250, 500, 250);
10.   line (0, 0, 500, 500);
11.   line (0, 500, 500, 0);
12.  
13.   float y = 0;
14.   noFill();
15.  
16.   beginShape();
17.   for (float x=-500; x<500; x=x+1) {
18.     y = (45*sqrt(x*x/(10000)+1.0))+128.834;
19.     vertex(250+x, 250+y);
20.   }
21.   endShape();
22.  
23.   beginShape();
24.   for (float x=-500; x<500; x=x+1) {
25.     y = (60*sqrt(x*x/(10000)+1.0))+88.445;
26.     vertex(250+x, 250+y);
27.   }
28.   endShape();
29.  
30.   beginShape();
31.   for (float x=-500; x<500; x=x+1) {
32.     y = (30*sqrt(x*x/(10000)+1.0))+169.222;
33.     vertex(250+x, 250+y);
34.   }
35.   endShape();
36.  
37.   beginShape();
38.   for (float x=-500; x<500; x=x+1) {
39.     y = (75*sqrt(x*x/(10000)+1.0))+48.056;
40.     vertex(250+x, 250+y);
41.   }
42.   endShape();
43.  
44.   beginShape();
45.   for (float x=-500; x<500; x=x+1) {
46.     y = (90*sqrt(x*x/(10000)+1.0))+7.668;
47.     vertex(250+x, 250+y);
48.   }
49.   endShape();
50.  
51.   beginShape();
52.   for (float x=-500; x<500; x=x+1) {
53.     y = (15*sqrt(x*x/(10000)+1.0))+209.611;
54.     vertex(250+x, 250+y);
55.   }
56.   endShape();
57.  
58.   beginShape();
59.   for (float x=-500; x<500; x=x+1) {
60.     y = (40*sqrt(x*x/(1600)+1.0))-3.18;
61.     vertex(250+x, 250+y);
62.   }
63.   endShape();
64.  
65.   beginShape();
66.   for (float x=-500; x<500; x=x+1) {
67.     y = (80*sqrt(x*x/(6400)+1.0))-12.488;
68.     vertex(250+x, 250+y);
69.   }
70.   endShape();
71.  
72.   beginShape();
73.   for (float x=-500; x<500; x=x+1) {
74.     y = (10*sqrt(x*x/(100)+1.0))-0.12;
75.     vertex(250+x, 250+y);
76.   }
77.   endShape();
78.  
79.   endRaw();
80.  
81.   println("dxf exported!");
82.   exit();
83. }

thank u for that. but I can not find the saved file

The file is saved to the sketch directory.

Either save the sketch somewhere so you know where it is.

Or press CTRL+K from the sketch so it opens the directory it's in.