Hardflow

Hardflow is one free GPLv3 extension for Blender 4.2+ covering the whole hard-surface loop — draw-to-cut booleans, precision snapping, direct modeling, curves, decals, and kitbash assets — in a single add-on.

✂️ Boolean workflow

• Draw-to-cut — Box / Circle / Polygon / N-gon / Slot / Star / Arc / Vent (grill) shapes, with Cut / Slice / Make / Join / Intersect / Face / Knife modes — in Object and Edit Mode.
• Precision — world-scale (meter) grid snap, vertex/edge snap, angle lock, a rotatable drawing plane, live grid density, and numeric exact-size entry (type a dimension to lock the shape's size).
• In-draw ops — inset, array (linear or radial bolt-circle), mirror, bevel-on-cut, in-plane rotation, and stamp/repeat, all while drawing — plus a live boolean preview of the real result before you commit (high-poly-friendly: it culls non-intersecting targets and skips idle frames).
• Panel lines — select edges, get a recessed groove seam or a raised weld bead in one click; open strips, closed loops, and T/X junctions all resolve cleanly — destructively or as live cutters.
• Non-destructive — live cutters in their own collection + a modifier-stack manager; bake when ready.

🧱 Modeling

• Build & direct modeling — cube / plane / cylinder / cone / sphere / tube primitives, Push/Pull, Offset, Object-Mode Edge Bevel + Loop Cut, a construction grid, guides, and loft/bridge.
• Super Modeling Mode — a SketchUp-fluid shell that shadows the native tools on its own Ghost-Grid snap chain (VIEW/SURFACE/X/Y/Z plane cycle, Tab cycles Knife → Extrude → Cut / Add / Slice / Intersect draw-to-cut booleans), with a per-tool undo journal: a whole tool session commits as one atomic Blender undo step.
• Smart Bevel — drops support/holding loops so the edge survives Subdivision; topology-safe on irregular post-boolean n-gons and validated against a live Subdivision pass (the loop pins the flat, fillet radius ≈ the bevel width).

➰ Curves & sweeps

• Freehand drawing — stroke a pipe/cable/sweep path (or click it point by point); the ink hugs the surface and reduces to clean anchors on release, and C smooths it into a Catmull-Rom spline that commits as an editable Bezier.
• Cable gravity settle — the rope relaxes with real scene collision, so it drapes over obstacles and rests on your geometry.
• Custom profiles & details — sweep CUSTOM cross-sections from a mesh outline or a curve bevel-object, and Detail Along Path repeats a detail mesh along the curve (chain links, cable clips, corrugated hoses).

🎨 Decals & trim sheets

• Full decal pipeline — placement, PBR material, bake, image library, atlasing, create/match/retrim/conform + an editable library.
• Trim-sheet UV editor — carve a sheet into free named rectangles right in the viewport, with background removal (chroma-key a flat/green-screen background to transparency).
• Heightmap decals — a dedicated grayscale height map (or the color's own luminance) drives depth independently of the albedo: Parallax Occlusion Mapping (recessed lines slide behind their lip at grazing angles) plus a normal-relief bump for real shaded depth, with an invert-polarity toggle.

📦 Kitbash assets

• INSERTs from a .blend library with a live preview, auto-scale, insert-grid snap, material inserts, and asset-pack export.

The pure-logic core is unit-tested (144/144, no Blender needed), every bpy path is verified headless in Blender 5.1.2 (142 tests), and the modal tools' interactive feel goes through a manual checklist — so bug reports are very welcome.

Repo / install: https://github.com/ugulay/hardflow

Hardflow is and stays free — it's GPLv3, and the architecture is built so features stay isolated, so feedback and contributions are welcome.