This is a very basic fluid simulation setup. There is a large cube as the domain, a smaller cube as an obstacle, and an icosphere as a fluid inflow. Trying to play this animation outright with Alt+A won’t work. You need to do two things first:

1. Select the domain object (large cube) and then go to the Fluid panel and choose a path where you want to store your simulation data. By default, it’s set to /tmp, but I highly recommend you choose another location to put it.
2. Press the large BAKE button in the Fluid panel. This will bake the fluid simulation data and store it on your hard drive. It may also take quite a long amount of time. Once it’s done, though, you should be able to put your mouse cursor in the 3D View and press Alt+A to playback the simulation.

After running the simulation once, you can start fiddling with the settings. Maybe increase the resolution of the final bake or change the fluid settings from water to oil. Have fun. This is one of my favorite parts of Blender.

Wheeeeee!

Files:

• fluids.blend

Here’s a simple cloth simulation. The grid mesh is set as the cloth and the cube is the collision object. Play the simulation by placing your mouse cursor in the 3D View and pressing Alt+A.

Like the other physics simulations in Blender, if you have an older computer, the first time this simulation runs it might be pretty slow. However, Blender will cache the results for you and the second time it plays, it should be nearly real time.

If you get a chance, play with adding fields like wind to this scene and perhaps animate the cube.  It’ll look sweet, I promise.

Files:

• cloth.blend