A pile of rice

Hello all:

I’m having trouble trying to make a pile of rice with particle system.
I just want to make a pile of some hundreds or thousands of grains with a particle emitter, but I can get the particles to behave like rice grains.
By using Physics of fluids, I recently achieved that they somewhat acumulates in a pile, but they still float without touching each other.

Are there any possible setting to achieve that?

Thank you for your help!

You could generate the “rice” using a particle system and a group of rice shapes.

After you create them, move the timeline so you see a lot of them. I do this on a separate layer just to isolate them for this step)

Select the rice particles and press SHIFT+CTRL+A to convert them to meshes.

Gather up all you new meshes and make them Active Rigid Bodies. Now all the rice grains will (should?) act as you want them to.

Thank you place. The idea seems cool, but I’m still having some troubles:

  1. I can’t set a dynamic property to all meshes at a time.
  2. I can’t find Active Rigid Bodies: I’m trying with soft body, but I have the problem #1, so I can’t set it to the 2000 meshes.
  3. The system is really slow once I turn the dups into real objects.

It seems that the Active Rigid Body concept works only under Blender Game engine.

I managed to apply rigid body to the whole particles by joining them into a mesh, applying the thing and then separating them, but it didn’t work anyway: particles floated away, and I don’t know this game environment.

Isn’t it possible to simulate rigid bodies under a rendering environment?

You may be able to leverage fluid particles. This coffee example file shows coffee beans in a bowl. Maybe you could alter it to be rice in a pile?

How close to the pile do you want to get? Here’s what I came up with for a close pile:

It can be done without using particles, and without the BGE. Add a plane for the floor, and it works best to extrude it to have some thickness. Go the physics panel and click the rigid body tab, then change it from “active” to “passive.” Here’s my trick. Create a cone in roughly the shape of the pile, and also make it a passive rigid body. My example image used 5000 grains of rice instead of the tens of thousands that would be required to fill all that volume without a cone.

Now model a grain of rice. Make sure the scale in the x,y, & z directions is equal to 1.0. Go to the physics panel and click the rigid body button, leave it set to “active.” The easiest way to make a lot of grains is to “SHIFT D” duplicate it, move it over a little, select both grains and repeat. You’ll go from 1 grain to 2 grains to 4 to 8 to… 2048 quickly. Press play and the grains will fall and settle on what’s below them.

You could also put the grains into a group, create a plane, subdivide into a 10x10 grid of vertices, parent the grains to it, turn on dupliverts, choose the grain group in the Object panel->Duplication-> Group tab, then “SHIFT-CTRL-A” to make duplicates real. Make copies from there. Quite a chore if you haven’t done it before.

*Make sure the grain object has a material and is has the rigid body settings you want before you start duplicating it. It can be changed in mass later, but once I have a few thousand grains on screen blender slows down on my computer and it takes a while to do selections, etc. It’s just easier to get it working on a few grains in advance and then copy those that already have the desirable settings.

*Drop your grains on the plain first and save an image texture. Then apply that texture to your cone so you can get away with fewer individual grains (the camera will still see a rice texture on the cone through the holes.

The example I gave you works perfectly well just as I described it and it does not have to be in the game engine.

1: create the grain of rice (in my example I used a cube)
2: add a plane for the floor make this a passive rigid body
3: add another place and add a particle system to the plane using using the “rice” as the object
4: run the particle simulator to create a lot of rice
5: stop the particle system, select it, then press SHIFT+CTRL+A to make the particles meshed
6: delete the plane with the particle system. The “rice” will stay there
7: select all the rice
8: move to frame 1
9: press “add active”
10: press play, the rice falls to the passive plane
11: you now have a pile of rice.

Maybe try it again with the more detailed instructions.

The only thing I don’t understand is how you “add active” and what’s that about. (in Blender 2.65)

Ok, I’m sorry, that is the new Rigid Body tools on the “T” panel. Also, after making the meshes if you select them all, then press U (make single user) and choose object and data you will make all the rice grains individual.

you need blender version 2.66 for viewport rigid bodys

Ey, man, I didn’t new that! I’m downloading the 2.66 now! Now all your tips will make more sense, I guess.

you’ll find it under the pysics tab along with the fluid/smoke /softbodys etc
youmay want to watch a few tutorials to get your head around the system first. cant help more than that as i never used it yet

Cool. I found it and I’m trying it. The thing works, but the objects does not behave as I expected: instead of just falling pulled by gravity, they explode away in all directions, and instead of settle in a mountain, they moves as ants or worms all around, even if I set the shape as a box and their masses to 1000… If someone can post a .blend file with an approximate example as the ones that Place and See460 showed, it would be cool.

rice_pile_small.zip (3.38 MB)

I deleted all but a few grains so the file size would be easier to work with.

That was my bad. Sorry, I just assumed you were using the latest. So we both learned something from this thread. (I have just re-learned not to assume things.) Happy Blending, and I look forward to seeing your progress.

Well, I learned that I have to give every detail before asking for help. I didn’t though that just a difference of version of 0.01 would introduce such new tool. Thank you all for your help! I’ll try with the see360’s model and I tell you.

I can’t find which setting is wrong in my model. It seems to be identical to the one See360 send, but my rices flies away.

I attach my model, to see if someone could find what is wrong. Meanwhile, I will start a new one from zero.


clases bodies.zip (1.31 MB)

your dropping your rice from a mile high!

have a look at the cgcookie buttons tutorial to check your settings as well. its different but the models just drop and slide a bit but they dont bounce around every where, perhaps it can give you a clue to where your going wrong.

Thank you! Yes, when I start from zero it seems to work. May be I used a too big scale in that example. Or may be objects inherited some hidden settings from when they were particles and I tweaked every setting. In fact I had to remove some particles assignment that remained sticked to the objects. Now, when I start from a clean scene, the problem does not appear.

I have to use a hidden container to help grains to get a mountain shape. If not, they slide away.

I have seen many animations in Blender with bricks that falls in a pile. I wonder how they did that without the Rigid Body thing appeared recently in the 2.66?

glad you figured it out. in previous versoins you would have needed to use the game engine to achieve the same effect, and that i have no clue about! :slight_smile: