How to animate slices through geometry with a different interior and skin? (e.g. like slicing a watermelon) I'd like to animate slicing through a object with a skin and interior. A simple example would be animating taking thin slices from a watermelon similar this:



While this is relatively easy when using simple geometry, it still required a lot of setup. This animation was built using boolean modifiers. There is a sphere for the exterior skin, a sphere for the interior, and two cubes used to create the slices by boolean intersections with the spheres. The sphere for the skin is slightly larger than the interior sphere. The cube for the skin is slightly offset from the cube for the interior. The setup is shown below,

This approach does not scale well when using more complex geometry or when using lots of objects.

I would like to scale this effect to include dozens or hundreds of objects.

Is there a simpler way to create and animate objects with skins and different interiors?

The blend file:
Depending on what you want your final outcome to look like you may not need to do anything more then a simple boolean modifier.

Here is a capsule with nothing more then a boolean modifier set to difference, and a animated cube as the target.


You can see it is possible to get a different material for where the boolean cuts the object. Here is how.


Add a second material slot to the object with the boolean modifier (this is the material you want for the "inside" of your object).

The target object (the object that does the cutting) also needs to have the same material.


That's all it takes to get a different material where the boolean modifier has cut.

You can read in further detail about how the Boolean modifier handles materials in the blender manual.