Boolean operations
Combine volumes, subtract a cutter, or keep only the overlap of selected mesh objects.
Before you start
Use Object Mode and select two or more supported editable meshes without active modifiers. Start with clean closed volumes and a visible overlap. Keep a copy of the operands when you need to reuse them.
Union
Union combines the selected volumes into one surface boundary.
- Position the meshes so their overlap matches the intended combined shape. Keep a duplicate if you will need the original operands later.
- Select the meshes, open Boolean in the modeling sidebar, and choose Union.
- Inspect the new surface around intersections and check the resulting material.
Subtract
Subtract removes later operands from the first selected mesh.
- Move the cutter through the base where material should be removed. For a through-hole, extend the cutter beyond both sides.
- Clear the selection, then select the base first and add the cutter. Open Boolean and choose Subtract.
- Inspect which volume remains. If operand order was wrong, undo and select again; with Agent, name the base and cutters explicitly.
Intersect
Intersect keeps only the space shared by the selected volumes.
- Position the objects so their shared region has the shape you want to retain.
- Select the operands, open Boolean in the modeling sidebar, and choose Intersect.
- Inspect the remaining volume. Undo and reposition the inputs if the result is empty or much smaller than intended.
Operand order and materials
| Controls | What changes |
|---|---|
| First operand | Subtract removes later operands from the first. Clear the selection and select the base first, then add cutters. Agent requests should name the base and cutters explicitly. |
| Material | The result uses a material derived from the first operand; input material assignments are not all preserved. |
| Union versus Join | Union computes a volume boundary. Join places geometry in one mesh object and leaves overlapping internal surfaces in place. |
Check the result
Inspect openings, interior walls, thin regions and normals from several views. Touching or coincident surfaces can create ambiguous results. Use Undo to adjust the operands; a successful Boolean is not a guarantee of deformation-ready topology.