The Boolean Modifier uses the shape of one mesh to change the shape of another in Blender. Its most common use is to cut a shape out of an object using another object. The modifier received improvements in Blender 4.5. Here’s a complete guide on how to use the Boolean Modifier in Blender 3D.
How to Add a Boolean Modifier
The Boolean Modifier should be added to the object you want to change the shape of. If using one object to cut into the other object, we place the modifier on the object that is being cut into.
Boolean Modifiers are added like all other modifiers. With the desired object selected in Object Mode, go to the Modifier Properties Tab and choose “Add Modifier.”
We can search for “Boolean” or find the Boolean Modifier under the “Generate” category in the modifiers list.
Boolean Modifier Settings
The Boolean Modifier has three methods of operation: “Intersect,” “Union,” and “Difference.” Each causes the two designated mesh objects to interact with each other in a different way. The default operation is “Difference” and this is used to subtract one object’s shape from another.
Difference
The “Difference” operation type subtracts one object’s shape from another. In the below image, we are subtracting a cylinder’s shape from a sphere (the modifier is attached to the sphere).
Union
The “Union” operation joins the two objects together, creating a larger object. In the below example, a cylinder’s shape is added to the sphere (boolean modifier attached to sphere).
Blender Add-On Spotlight
Intersect
The “Intersect” operation will remove all the non-intersecting parts of the two meshes. So, only the parts that overlap will be displayed. The below image shows the same two objects from the previous examples in “Intersect” mode.
Operand Type
The “Operand Type” setting on the Boolean Modifier allows us to choose a single object or a collection of objects to use as the boolean object. The selection of “Object” will give us an option to select a single object. Choosing “Collection” will allow us to choose a collection of objects.
In the example of using other objects to cut into the main object, this allows us to use more than one object as a “cutter” while only using one Boolean Modifier.
We simply must add our “cutter” objects to a collection and use the collection as a cutter.
Solver & Solver Options
The “Solver” settings for the Boolean Modifier in Blender tell Blender how to calculate the boolean effect. With the release of Blender 4.5 there are now three solvers: “Fast,” “Exact,” and “Manifold.”
Float
The “Float” solver is traditionally the faster solver. It will minimize the drag in the viewport while displaying boolean results. However, the new “Manifold” solver option may be a better choice for most objects.
Exact
The “Exact” solver is more accurate in delivering results in the viewport, but it may cause lag in the 3D viewport, especially with more complex meshes. This is historically the default solver.
Manifold
The “Manifold” solver was added in Blender 4.5 and is the fastest of all the solvers. However, it will only work with “manifold meshes” which are essentially meshes which are fully enclosed. In most cases, this is now the solver we probably want to use.
Solver Options
There’s a collapsible setting labeled “Solver Options” on the Boolean Modifier called “Solver Options.” This provides fine-tuning of the solvers and has different parameters depending on which solver is selected. Honestly, I don’t know what these settings do and I’ve never needed this level of fine-tuning with the Boolean Modifier. For most, you can likely ignore these setting options.
Boolean Modifier Video Tutorial
I’ve of course put together a video tutorial on the Boolean Modifier which may provide a better explanation. If you like it, don’t forget to become a subsciber on my YouTube channel.
Thank you and stay creative!
Brandon Stocking
