'Cloth' Meshes as Particles Effected by Wind / Particles Following a Path?

Hello Blender Artists!

I’ve been attempting to teach myself some new techniques with a specific end goal in mind, I’ve recently completed working through several of Blender Guru’s tutorials (creating sparks to start working with particles, the flag blowing in the wind to start understanding some dynamics of cloth / wind interaction) but I have a few specific questions / am curious if some of the following is possible.

The original idea is to have a series of plastic bags slowly blow their way into the scene and begin to accumulate en mass (in the beginning maybe one will be blowing around in the manner of the classic scene from American Beauty [can be found via searching ‘plastic bag in the wind’ on youtube] but over time there may slowly gather dozens and dozens). In the beginning I’d like them to lilt and float around randomly (the best solution here seems to manually animate the creation and movement of wind generators to give the effects of ‘swirling’ wind being buffeted by walls, etc…) and have each ‘bag’ be a particle being generated by particle system. After many of them have gathered I’d like to have them start blowing in very specific ‘paths’ and here I am completely bewildered: ideally, I’d like to have all of the plastic bags be ‘blown’ into patterns (for instance, they may all begin to blow in a ‘figure 8’ or ‘infinity symbol’ pattern).

So my final questions are these:

  1. Is there a good way to model a ‘cloth’ object with an open interior (the ‘inside’ of the bag) so that it will be effected by the wind and carried about?

  2. Is it possible to create a particle system where each ‘particle’ is the mesh object of the plastic bag where each is effected individually by the wind system?

  3. Finally, is it possible to make a particle system blow about or follow a ‘path’ (or perhaps a bezier curve?)

Thank you very much for all of your help and time in advance! I’m somewhat proficient in Blender at my level but this is reaching into new territory so even suggestions for other threads / tutorials dealing with parts of this project would be very much appreciated!

  1. Yes, create an Empty and add a Wind force field under the Physics TAB.

3.) Yes, create a curve and add a Cruve Guide force field to the curve under the Physics TAB. When you do this, each end of the curve will have a big circle added to it. One is a dotted line the other is a solid line (entry/exit). Move the emitter close to one of the ends and the particles will be attracted to and follow the curve. The field strength determines how much the particles will ‘stick’ to the path.

When using fields and particle systems they are layer based. That is to say, the particle system and the field you want to influence it have to be on the same layer. NOTE: If you are using a mesh based particle, such as your bag, as a source mesh, it can reside on another hidden layer. As long as the particle system that is deploying the particles is on the same layer as the fields that will affect it.

Wind in general is has been a big let down for me. All I can say it make sure you set flow to at least 1.0. What you can do to enhance the randomness of wind is to add a noise texture to the particle system itself and make the texture affect the field strength.

What you can do to enhance the randomness of wind is to add a noise texture to the particle system itself and make the texture affect the field strength.

Is there anyway you can elaborate Atom, on how to specifically do what you mentioned on the noise texture tip?

@harleynut97: Sure, here is an example BLEND file setup. The RED emitter has its own wind on its own layer. The BLUE emitter has its own wind on its own layer. I have set each emitter and wind field to have the same settings. So they should produce the same animation. But the BLUE emitter has a Distorted Noise texture affecting the field influence. Where the texture is black, the field influence is zero and where the texture is white, the field influence is 1* the field strength set in the panel (highlighted in yellow). The texture is evaluated left-right over time. So you can animate the offset of the texture for an even stronger effect.

I consider this a secret function, because you have to click the particle icon TAB to activate the particle context then click the texture icon TAB to reach the panel where you can change these settings. Many users, myself included, thought textures were only for materials but the current context, prior to clicking the texture icon TAB, changes where the texture is applied (material, world, particles).

I hope that explanation is clear enough.


265_wind_particles_1a.blend (517 KB)

Thanks for taking the time to post this atom… going to download and take a look right now… thanks again

Fantastic responses, going to take a look at your examples now! Having a bit of trouble implementing some of your suggestions but I’m going to take a crack at continuing to research and try out a few things before I come back (to make sure I thoroughly understand what I’m missing). Will post back if I can’t work it out on my own.

Thanks again!