Booleans¶

Booleans combine meshes: merge them, cut one with another, or keep only where they overlap. In World Toolkit they're non-destructive: the original meshes stay untouched and the result rebuilds whenever you move or edit them.

How it works¶

A Boolean Stack holds the result, on its own object. Each mesh that takes part has a Boolean Operand component that points to the stack:

• One operand is the Base, the mesh everything else is applied to.
• Every other operand applies its Operation to the result so far, in order.

The result is computed in the background, so the editor stays responsive while a heavy stack rebuilds. Its faces keep the materials they had on their operand.

An operand can be another Boolean Stack: the stack waits until that one is up to date, then uses its result.

Creating a Boolean Stack¶

In the Create tab, under Booleans:

1. Select the meshes to combine. The first one you select becomes the Base.
2. Click Create new Stack.

This creates a new Boolean Stack object. The other meshes join it with the Difference operation, which you can change afterwards. With nothing selected, it creates an empty stack you can fill later.

To add another mesh to an existing stack, select the new mesh first, then the Boolean Stack last, and click Add to stack. The mesh joins at the end of the stack with Difference, or as the Base if the stack is empty.

Auto Disable Mesh Renderer

Hides the original meshes once they join a stack, so you only see the result.

Auto Remove Colliders

Removes colliders from the original meshes once they join a stack.

Editing the stack¶

The Boolean Stack inspector lists its operands, in the order they're applied. For each one you can:

• Change its Operation.
• Choose which operand is the Base.
• Mute it to temporarily leave it out of the result.
• Swap it for another operand in the Operand field.

Drag the operands in the list to change their order. The Base always stays first.

Rebuild asks for a fresh build of the result, and Make Editable bakes it (see below).

When something prevents the build, a warning at the top of the inspector says why, for example:

• No active Boolean Operand is marked as Base.
• Multiple Boolean Operands are marked as Base. Exactly one Base is required.
• The Base Boolean Operand is muted.

Boolean Operand¶

The Boolean Operand component on each mesh has the same settings as its row in the stack, and a few more:

Stack

The Boolean Stack this mesh belongs to.

Base, Mute and Operation

As in the stack's list.

Order

The position of the operand in the stack. Dragging operands in the stack's list sets it for you. Order and Operation are disabled on the Base, which always comes first.

Show Input

Keeps the operand's own mesh visible, to see and edit it. When it's off, the stack hides that mesh while its result is up to date.

Invert Open Side

For open meshes (like a single plane) used as cutters, flips which side counts as "inside".

Baking the result¶

Make Editable in the Boolean Stack inspector turns the result into a regular Editable Mesh you can edit vertex by vertex. After that, it no longer updates from the operands. It's available once the result is up to date and the stack has no warning. Make Editable at the top of the Topology tab does the same for the selected stacks.

Surface Cut¶

For a quick, one-time cut that doesn't need a stack, use Surface Cut in the Topology tab. See Editing Tools.