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# 3D curves

FAQ   •   VIEW ALL
 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?

cervelo

 Re: 3D curveson 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 curveson 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 curveson 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.

Valerio