Water Tank
By Pascal Fallert

Introduction Sometime ago I made a fluid simulation and put it on YouTube. I was asked how I did that, so I decided to make a tutorial. Well, here it is.

Step 1. Create a cube, dimensions x=5, y=3, z=4. Name it "Domain"

Step 2. Add an icosphere: Subdivision=2, Radius=0,2. Scale it in edit-mode on the X-Axis 0,3. Location x=-2, y=0.5, z=3.

Name it "Inflow"

Step 3. Duplicate (Shift- D) the first cube, and move the sides and the bottom about 0.04BU towards the inside. The height should be about 1BU. Name it "Fluid", this will be the water that is already in the watertank.

Step 4. Now the Fluidsettings. Select the "Fluid-Mesh", go to Physics and enable the Fluid-button. Use the settings below:

Step 5. Select the "Domain-Mesh", enable the Fluid-button. Define the Mesh as Domain. On the Std-page, change End to 12. On the Adv-page, change Gravity Z to -20, and Realworld-size to 1.

Step 6. Select the Inflow- Sphere, enable the Fluid-button. Define the Mesh as Inflow. Leave the Settings, because we will use an IPO to control them. Step 7. IPO for the Inflow-Sphere. Open the IPO-editor and change the IPO-type to "Fluidsim". The Active- IPO activates the inflow on Frame 31, and stops it on Frame 151. Add a linear curve with the Points:

P1(x=30, y=0); P2(x=31, y=1); P3(x=150, y=1); P4(x=151, y=0).

The first 30 frames are for the fluid-object to "drop down". I don't use them for rendering, but in order for the waves to tranquilize. Maybe there's a better way to do this, but that's how I did it.

The second IPO-curve controls the velocity for the xdirection. It starts at frame 31 and rises up to 5 at frame 51.From frame 130 up to 150 it falls bak to level 0. This makes the water fade in and out smoothly.

That's it. Select the Domain-mesh, go to Physics and hit BAKE. For a realistic result, you have to change the resolution to 200 or more, but this takes very long to calculate. It's useful to have a second computer to work with, while the first one calculates the simulation. Move "Inflow" and "Fluid" to an invisible layer, and set "domain" to smooth.

You should get something like this (frame 43): Render the frames 31 to about 250. You can find the Animation on my homepage. or on Youtube.

Here's a still from my simulation:

I hope you can use this tutorial, and make animations by yourself. If you have any questions, or know better ways to achieve this, please feel free to send me an email, or post a comment on Youtube.

Pascal Fallert