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I'm wondering how to approach this problem. I just watched a video on how to get particles to "morph" shapes, but what I'm looking for is more natural-looking... My specific idea is to have pieces of candy corn fall into the letters BOO! I can figure out the particle system emitter, and I can get the particles to fall, but I'm scratching my head on how to get them to naturally fall into the BOO shape.

Are there any good resources for this kind of simulation?

Thanks!

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  • $\begingroup$ you need to give your letters a Physics > Collision, but maybe share your file so that we see where is the problem more precisely $\endgroup$
    – moonboots
    Oct 22 '20 at 10:11
  • $\begingroup$ I should clarify: I'm not trying to get them to fall into a physical object... the idea is that the particles fall onto a flat plane, but the particle trajectory/path's end position is going to spell out a word. I'm still working on my blender file at the moment. I'll try a couple things and then post my .blend file. Thanks! $\endgroup$
    – n0ah
    Oct 22 '20 at 11:12
  • $\begingroup$ so maybe create some letters and make them invisible? $\endgroup$
    – moonboots
    Oct 22 '20 at 11:17
  • $\begingroup$ I'm not sure I'm following.... I added my .blend file to my original post, in case you wanted to poke around. $\endgroup$
    – n0ah
    Oct 22 '20 at 12:01
  • $\begingroup$ something like that except you make the letters invisible in render: zupimages.net/up/20/43/ofmm.gif $\endgroup$
    – moonboots
    Oct 22 '20 at 12:13
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You could do it backwards. Have a mesh (set to not be visible in the render itself) define the shape for the particles to end up in, have this mesh start with a lot of particles only inside its volume, and then animate them all 'falling' randomly upwards under an appropriate force. Then reverse the animation, either externally or via baking it and reversing the order of keyframes.

Whether this looks good or very faked will depend on the look you're going for and the shapes of your targets.

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  • $\begingroup$ Thanks @Ben, you've given me an idea for this year's Christmas card! :) $\endgroup$
    – Edgel3D
    Oct 22 '20 at 23:58
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Start the animation with a huge number of particles and make them fall onto the plane.

Bake them and transform the particles into real objects with keyframes.

Select all the particles and remove from selection (You can use the C shortcut to activate the circle selection) those in the places you want to save (where the letters should be drawn) and delete the others.

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You can create invisible letters and make your candies fall into. For the letters, in the Properties panel > Physics > Rigid Body > Collisions > Shape, choose Mesh:

enter image description here

If you don't want candies to fall out of the letter, once they have fell into the letter, you can select them all at frame X, go in the header menu > Object > Rigid Body > Bake to Keyframes, then, as suggested by Ben, give them a new Rigid Body, but this time make them move up with a Gravity of -1 in the Scene settings, or with some Force Field, then invert the render so that they fall down into the letter.

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  • $\begingroup$ Very nice! Absolutely better than my solution! $\endgroup$
    – mugnozzo
    Oct 23 '20 at 7:24
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Fake physics with keyed particles

enter image description here

Keyed particles allows to drive in time the movement of the particles along several objects.

The driver has itself a particle system in which settings we can define the sequence of other objects the particles will go through.

The objects of this sequence have their own particle system (with eventually their own parameters).

Here I've placed:

  • a cube to start with,
  • a plane that will fake the point where particles should fall to the table,
  • another shape that defines the surface of the table the particles fall on
  • the text object

The driver particle system has the following settings:

enter image description here

where:

  • Physics is set to keyed
  • Use timing is on
  • In relations are added the object sequence
  • And for each of them we indicate the time (in frames) at which the particle will be on it and the duration it will stay on it (these times are relative to its birth)

The documentation is here.

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  • $\begingroup$ Applied Remesh modifier with 0.01 used on letters helps to even distribution (especially on letter B :) BTW particles are quite crossing each other, I'm wondering if that can be avoid somehow? Thanks :) Great answer. $\endgroup$
    – vklidu
    Oct 24 '20 at 11:14
  • $\begingroup$ @vklidu, thanks for this comment. I was not able to make rigid body work when using keyed. So, yes, they overlap. Don't know if there is a solution. $\endgroup$
    – lemon
    Oct 24 '20 at 11:16
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Rigid Body

enter image description here

enter image description here

Convert particles to Rigid Body (with add-on or if you don't mind how they appear on scene just apply particle modifier). Similar to moonboots's answer, but ...

  • Use one plane collider as floor to let candies fall on a desk.
  • Then use another collision object with letters shape extruded conicaly upward, and animate location on Z axis.

enter image description here

enter image description here

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