## learning jitter expressions

Feb 24 2010 | 9:18 am
I try to learn jitter expressions because there the core of jitter . Can you recommend good books (maths or other anything) that can help me to understand these "mysterious" expressions.

• Feb 24 2010 | 11:35 am
the easiest way is to create a new object and start typing either "cv.jit.___" or "jit.___" and select any of the object expressions that appear in the drop-list. then (in edit mode) alt+click the object and learn more about, copy it, edit it-whatever you please.
• Feb 24 2010 | 12:05 pm
• Feb 24 2010 | 2:02 pm
oh-i'm sorry. my bad. i have no idea. :(
• Feb 24 2010 | 6:11 pm
there's plenty of examples on the forum, as well as in the jitter recipes.
other that that, i would say, stay tuned to the cycling74 articles website.
• Feb 24 2010 | 6:41 pm
Thanks , I know there plenty of articles but the problem is that i don't have a knowledge base and when i want to put my ideas in practice i realize that i'm lost.
The forum is like a candy store. A lot of tastes hide the ingredients :)
• Feb 25 2010 | 11:20 am
I speak about expressions like :
expr " pow(min(norm[0] , sqrt(norm[1])) , 2.0)"
or
expr sin(norm[0]*(2*PI))*sin(norm[1]*(2*PI))
or
I was not very good of math ( I know basic geometry) so i tried to find some good books. I need to study analytic geometry or matrices? Can you recommend some books that will illuminate me ?
Thanks
gobo
• Feb 25 2010 | 6:01 pm
i can't really think of a much better resource than the googles.
this guy's site is chock full of information and equations: http://local.wasp.uwa.edu.au/~pbourke/geometry/
most of these geometric shapes can be created with jit.expr and jit.gl.mesh.
for a more concrete example, recently i wanted to create a spiral shape, so i googled spiral equations, or something like that, and found this: http://www.mathematische-basteleien.de/spiral.htm on down the page if found the spiral equation in needed x=tcos(6t) y=tsin(6t) z=t
i plugged this into jit.expr using norm[0]*5 in place of t (found by experimenting), and plugged the output into jit.gl.mesh. viola. 'jit.expr @expr (norm[0]*5)*cos(6*(norm[0]*5)) (norm[0]*5)*sin(6*(norm[0]*5)) (norm[0]*5)'
hopefully this is helpful, but if not, as mentioned, stay tuned.
• Feb 26 2010 | 11:57 am
Thanks , I will try to learn using trial and error. if I will be blocked , I will ask on forum.
• Feb 26 2010 | 4:05 pm
@robtherich can you expand on how this works in patch form. i just tried to code this as u describe and i get nothing...
could you post your spiral patch so we can get an idea of how u implemented this.
thanks
j
• Feb 26 2010 | 6:39 pm
• Feb 26 2010 | 7:48 pm
thanks v much for the share.
j