by Dan-Gry·Modeling
Images © Dan-Gry. Used for product review; image policy.
Half Knife earns its place in the blender_extensions library for a knife workflow focused on speed, with modal snapping and an optional no-preview cutting mode.
Half Knife is a knife tool for Blender built for a fast cutting workflow. You can start a cut with no initial selection by mousing over the mesh and pressing K, then clicking to set the end of the cut, or press K with an existing selection and click to set the end point. A maximum of 10 initial vertices can be selected, a limit set for performance and to exclude accidental use.
The tool supports multicuts from face or edge mode, where a selected edge counts as two vertices and a selected face counts as its N selected vertices. Several modal options refine each cut: Shift turns off snapping, Z cuts through, Ctrl snaps to center including the middle of a face, Alt uses an alternate snap to center, C applies an angle constraint to half and quarter angles, and H enables Altitude mode to create an orthogonal edge.
A 'Cut without preview' option, enabled in the Keymaps tab, lets you cut without pressing mouse buttons. Half Knife is not a full replacement for Blender's default knife tool, and cutting concave ngons can produce broken geometry. A tutorial video is available.
Half Knife is best for blender modeling artists who want a fast knife tool with snapping and angle-constraint options for precise mesh cuts.
Half Knife is completely free to download and use.
Half Knife lists compatibility with Blender 4.5 LTS and newer. The addon's documentation also notes it was tested on Blender 2.91, with newer versions supported as they come up. The extension requires no special permissions to install or run. If you work across several Blender versions, check the developer's page for the current version history and any version-specific notes before installing, so you know which release matches your setup.
Half Knife includes a 'Cut without preview' option that lets you make cuts without pressing mouse buttons. To enable it, open Blender preferences, go to Addons, find Half Knife in the list, then open the Keymaps tab and check the 'Cut without preview' option. Note that when the operator is invoked from outside the mesh, the preview will still be shown. This is separate from the standard workflow of pressing K and clicking to place the cut.
Half Knife offers several modal options while cutting. Shift turns off snapping and Z cuts through. Ctrl snaps to center, including the middle of a face, while Alt uses an alternate snap to center that cuts in-between edges in a straight line. C applies an angle constraint, snapping to half or quarter angles between the active vertex and linked edges. H enables Altitude mode, which creates an orthogonal edge from the selected point to the edge you are pointing at.
Half Knife works with modifiers, but you should uncheck the 'On cage' button on every modifier first, otherwise cuts will go in the wrong direction. It is also worth knowing that Half Knife is not a full replacement for Blender's default knife tool: cutting concave ngons can result in broken geometry. By default, Blender's own knife tool is assigned to the Alt K shortcut, and you can change shortcuts in preferences.
Half Knife is listed as free here and is distributed under the GNU General Public License v3.0 or later. The extension requires no special permissions to install or run. You can drag and drop the addon into Blender, or download it and install from disk. For current licensing terms, the version history, and the latest release, check the developer's page linked from this card.
Also in Modeling for Blender.
by zets
Terrain Mixer is a shader-based terrain generator for Blender that runs on Cycles. Built by zets, it uses a node-based workflow across Cycles and Geometry Nodes to create both realistic and abstract terrains from the 3D Viewport.
by Dan-Gry
ND Primitives is a Blender add-on for adding non-destructive parametric primitives. Shapes can be edited in Edit Mode without applying modifiers, and the modifier can be re-enabled later to keep tweaking parameters in Object Mode.
by Mark Kingsnorth
Flowify is a Blender add-on for 3D modelers that bends an object onto a surface with evenly spaced four-sided faces and four corners, or onto a cylindrical surface, using a flat reference grid to guide the deformation.
by Armored Colony
Curve Basher is a Blender add-on for generating curves and applying kitbash on top. It bundles curve generators, a Wire Generator, and a preset browser, plus included sci-fi cable and chain presets.
by BeFX Studios
Matplus is a paint layer system for Blender that brings real-time effects, 2D symmetry, and optimized texture baking into the scene. Inspired by Substance Painter and ArmorPaint, it needs no external software.
by Community
LoopTools is a mesh modelling toolkit for Blender that gathers several tools to aid modelling. It was previously part of Blender 4.1's bundled add-ons and is now offered as an extension, provided as it is with limited support.
by Community
Extra Mesh Objects is a Blender add-on that expands the Add > Mesh menu with additional mesh object types. Previously bundled with Blender 4.1, it now ships as a standalone extension for Blender 4.2 LTS and newer.
by nickberckley
Bool Tool brings quick boolean operators to Blender for hard-surface modeling, covering brush booleans, destructive auto boolean cuts, and workspace tools that carve objects with custom shapes in both object and edit modes.
by Community
Extra Curve Objects is a community add-on for Blender that adds extra curve object types. It lives under View3D → Add → Curve → Extra Objects and was previously part of Blender 4.1's bundled add-ons.
by MACHIN3
MESHmachine is a mesh modeling addon for Blender focused on hard surface work without subdivision surfaces. It fuses and unfuses surfaces, creates variable fillets and washouts, edits bevels, and details meshes with plugs.
by Community
A.N.T.Landscape is a Blender add mesh add-on for generating landscapes and displacement. Originally a bundled add-on in Blender 4.1, it's now offered as-is with limited support, accessed from the View3D sidebar's Create tab.
