# Make particles wiggle (in a sine wave)

I'm trying to model a laser, and I'm using moving particles that are emitters. Using some motion blur, I get something that looks like particles going very quickly. However, I would like to give the impression that this is a laser, so I was thinking about making the particles move in a sinusoidal motion to make them look like little sine waves (a crude rendition of the particle/wave duality of light, I admit.)

I think that this effect should be achievable if I could make a texture field that would apply an up/down force on the particles. But, I cannot figure out how to define the texture used by the texture field.

here is what I have so far, showing the laser in red hitting a nanoparticle and ejecting ions (yellow/white). I am using the Cycles renderer.

I would tackle this problem by using a curve guide force field where Kink is set to Wave. Frequency and Amplitude will help you to shape your movement.

I prepared a blend for you that illustrates the behaviour clearly and upload it here http://www.pasteall.org/blend/29048

This screenshot should help all of you that don't like to download foreign blend files ;)

Consider that the wave kind is behaving like a sawtooth wave... so maybe you should form your curve guide like the sine wave you'd like to create.

Another way is to use a harmonic field... for a demo of this effect, look here: http://www.pasteall.org/blend/29061 The movements here are less uniform. If you need even more turbulence use the turbulence field on top..

• Hmmm, the file that you sent doesn't produce the particle wave like that. They just go in a straight line. Also, is it possible to get all of the particles to follow sine waves independently? I want them all wiggling independently, not clumped together in the same path. Thanks! Commented May 9, 2014 at 14:47
• See my edited answer... and mark the answer as solved if it does solve the problem :) Commented May 9, 2014 at 18:27
• Your new solution still has them all converging and diverging in one big wave. I want them to all follow their own, separate wiggling path. Commented May 11, 2014 at 15:12

create a sinewave with add->mesh->mathfunction>ZMathSurface setting the function as sin(x) (obtaining z=sin(x)) with x up to 6.28 (for one pulse),set number of x-divisions at 64 (or more for better resolution), y-divisions at 3 (the minimum) then edit the obtained (Z sinewave)surface deleting 2 of the 3 divisions on Y axis (Alt+RMB on the edges to select entire connected edges on a side). Now you understand why I used 3 Y-div... The resulting sinewave is still a mesh, you have to convert it to a curve (Object->Convert to->Curve from Mesh). I suggest to apply scale and rotation first you convert the mesh to curve. Once converted remember to check the Path Animation check-box in the curve's properties to enable particles following the curve field.