Once our half cylinder is hidden, we can see the hole in the left-hand side of our bracelet plate. The right-hand side, however, is still completely solid:
The base with just a single hole.
This is due to the order of the modifiers, the Modifier Stack. Blender applies the modifiers from top to bottom, as they are listed in the Properties window. In the case of our bracelet base, Blender currently does the following:
- Combines the cylinder and the cube to make a rounded half base
- Mirrors the rounded half base to make a full base
- Subtracts the half cylinder to make a hole
Modifiers are applied in order from top to bottom
The Mirror Modifier cannot copy a hole which is yet to exist. Changing the order of the Modifier Stack can produce very different objects. Suppose we put the Mirror Modifier last. The Union is applied, giving our base...