Floating Open Object

This is a tutorial for partially submerged object with an open face such as a crate, a boat or a cup. This is for those who want to animate a boat partially submerged without filling the boat with water. This is not necessary for solid objects.

Difficulty: Intermediate

This method uses the boolean modifier to create a hole on the water the shape of the displaced object. The boolean modifier need two objects with volume to work. I tried with a plane object but it doesn't seem to work.

First add two cubes [Space Bar]. Resize [S] on of the cube as shown below. Rename the cube "water" and the other cube "box".

Duplicate the box. Resize it slightly bigger than the original box. Rename it boxfield. Parent boxfield to box.

Select water and goto Edit Buttons [F9]. Add boolean modifier. Select Union and type boxfield for object.

Hide boxfield to another layer [M]. Delete the top face of the box. Add your textures. Animate and enjoy.

A YouTube example.

You can also read this tutorial at the Blender Artist forum thread.