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This question already has an answer here:

I would like to have plants, rocks, sticks and other debris scattered randomly on the ground in my scene, but I don't want to have to place it all there by hand. Is there an easy way to do this in Blender?

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marked as duplicate by Ray Mairlot, David, gandalf3, Keavon, Polosson Apr 28 '14 at 0:10

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Placing Objects Randomly on the Ground with a Hair Particle System

Using a Hair Particle system is a very easy way to have objects scattered randomly on your ground plane. This can be very useful for creating litter in cities, rocks & sticks in woods, trees in forests, weeds in abandoned lots, etc:

enter image description here


Step #1: Create your Objects

  1. Add to your scene one of each type of object you want to have scattered on the ground. In this example, I'm using 3 objects:

    enter image description here

  2. Each object's Origin Point is the point where the object will touch the ground plane. So, make sure to place the Origin Point accordingly. In this example, we'll move the Origin Point of each object to the mesh's bottom-most point:
    Select an object > Edit mode (TAB) > select all (A) > move the object up until it's Origin is at the base of the object:

    enter image description here

  3. Now make all your objects a Group by selecting them all and pressing CTRLG

  4. Then name your group something like "Object Group" in the Tools panel (T)

    enter image description here

  5. Now rotate all the objects 90 degrees on the Y axis. This is very important because in hair particle systems, particles use the global +X axis as "up" for orienting the particle (or object, as in the case here):
    Object Mode > select object > R > Y > 90

    enter image description here

  6. You can now move them off to the side or to a different layer -- just don't rotate them.


Step #2: Make Your Particle System

  1. Add a Hair particle system to your ground plane:
    Select ground plane > Object Properties window > Particle System tab > click New > set Type to Hair

    enter image description here

  2. For the particle system, make the following settings:

    • Enable Advanced
      enter image description here

    • In the Render section, select Group, and set Dupli Group to your object group, and enable Rotation
      enter image description here

    • Enable the Rotation section, set Initial Orientation to Normal, and the (Rotation) Random to 1
      enter image description here

    • In the Physics section, adjust the Size of your objects, and if you want some of the objects to be random sizes then adjust Random Size
      enter image description here

    • Adjust the Number of objects in the Emission section
      enter image description here

    The result is a scattering of your objects over the ground:

    enter image description here


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  • $\begingroup$ Is there any way that the objects in group can be replicated through particles(as you described), but no scaling is applied to those scattered objects (Scale of scattered objects shall be similar to the grouped objects) ? $\endgroup$ – Naresh Vijh Dec 23 '17 at 8:54
  • $\begingroup$ Yes, if I remember correctly, in the “Render” section, do not enable “Scale” (so no checkmark in that box.) $\endgroup$ – Thom Blair III Dec 23 '17 at 9:21
  • $\begingroup$ Just tried you recomendation but no use :(......I believe it's Emission > hair length =1; Physics > Newtonian > Size=1. But, not sure. $\endgroup$ – Naresh Vijh Dec 23 '17 at 10:56
  • $\begingroup$ If you can, disable Random Size. Maybe set it to zero? $\endgroup$ – Thom Blair III Dec 23 '17 at 10:58

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