| **3D curves**
on Apr 2, 2009 at 12:19:17 pm |

Hi,

I'm trying to build 3D curves (as seen in

http://www.mathcurve.

com/courbes3d/bicylindric/bicylindric.shtml) animating a Light Emitter for Trapcode Particular. The idea is to rotate and animate them to create kind of futuristic display or stuff like that. I tried to rotate Null Objects but i can't get what i want, and I dont know how to translate the

expressions in After effects expressions. Any idea?

Thanks in advance

cervelo

| **Re: 3D curves** on Apr 2, 2009 at 3:30:43 pm |

Hi, can't get it to work with the +/- and the square root in Y, but with some different values for a,b,c it looks like I can get most lissajous type curves, but not the "double" curves where there are two circles though...

so I applied this to the position of a 3D Null:

t=time;

a=1.5;

b=1;

c=0.2;

x=a*Math.cos(t);

y=Math.pow(b,2) - Math.pow(2*c + a*Math.sin(t),2);

z=c+a*Math.sin(t);

value + [x,y,z]*50;

You can then just pickwhip the emitter position of your particular to that position you're done.

to orbit around these, parent your camera to a 3D numm and rotate the null.

| **Re: 3D curves** on Apr 2, 2009 at 5:44:55 pm |

Thank u very much for swift reply, i tried it in hurry n it's working good. I just have to figure out how to make it symmetrical and how to stop it after the first cycle (i guess i can keyframe a slider instead of the time) cause the expression is not very clear for me

cervelo

| **Re: 3D curves** on Apr 6, 2018 at 7:44:51 am |

Hi everyone,

i'm trying to do a similar expression in after effects in order to represent a lissajous 3d curve. I've found the expression on the same website as corrado already posted. but this expression contains "phi" and "psi" and i don't know how to write it in a after effect expression.

if anyone could help me would be awesome.

thanks in advance.

Valerio

| **Re: 3D curves** on Apr 6, 2018 at 8:01:13 am |

Since by their definition they are sin waves (or cos waves) why not use sin or cos instead of sqrt or pie? The nice thing about sin waves is they repeat naturally and sin is a built in math function.