Carver: Cutter Properties
Cutter properties are the same for all three Carver tools and deal with actual cutter objects that will be created with the drawing, as well as the boolean modifiers that will use them. Cutter properties are less about the look of the cut, and more about the general hard-surface modeling workflow.
In Blender whenever a new modifier is added to the object it is added to the bottom of the stack. That ensures that the modifier gets evaluated mesh as an input, and not the original mesh (before the modifiers). But in hard-surface modeling workflow, you usually want to avoid that, because boolean modifiers are very disruptive and can mess up, or even cancel the effect of other modifiers by creating n-gons and breaking loops.
Pin Modifier property ensures that a new boolean modifier (whether in Destructive or Modifier workflow) is added as the first of the stack and is fed the original mesh. That way modifiers like Bevel and Subdivision Surface work ON the carved mesh, rather than boolean modifiers cutting beveled and subdivided mesh.
Carver tools have their own property for parenting and are not dependent on add-on preference (which is for brush booleans).
- by default, all cutters created by the tool are parented to the active object (even if they cut multiple objects at once). This ensures that when the canvas object is moved, cutters all follow and don't break the booleans (and have a performance impact in some cases). This can be disabled with "Parent to Canvas" toggle.
- If there is no active object in the view layer it automatically chooses the first object in selection as a parent, which sometimes can seem little random, so it's always recommended to have an active object.
- For modifier workflow new property "Hide Cutter" is enabled by default. Cutters (especially when displayed as bounds, rather than wireframes) can get in the way of modeling and clutter the view. They can also be cut themselves if they're selected, so avoiding all that by hiding is useful.
- Cutters are added in the "boolean_cutters" collection whether they're hidden & parented or not. But if they're parented to the canvas they're also linked to scene collection, so that they can be selected and unhidden from the canvas hierarchy in Outliner, without having to use the "boolean_cutters" collection.
In Blender, when boolean modifiers are applied cutter's normals are transferred to new faces created in canvas. That feature can be utilized to create smoother looking cuts without having to use too many vertices. When "Auto Smooth" is enabled in tool properties cutter objects get shaded smooth, with sharp edges (angle of which is controlled by "Angle" property) marked as Sharp (sharp edges are also transferred to canvas).
NOTE: Even for modifier workflow, Shade by Smooth is done destructively and not with a modifier.
If you manually change cutter in edit mode, you need to put a modifier on it from right-click menu (Shade Auto Smooth)
 |
 |
|---|---|
| Circle tool, 16 vertices Auto Smooth on |
Circle tool, 16 vertices Auto Smooth off |
It is recommended to always have "Smooth by Angle" modifier on canvas objects in hard-surface modeling workflow to avoid shading issues.