Name: NASSCAD
Author: Nasser

🖱 3D View Navigation

Left click	Select an object — stays instant even on very large scenes
Left click + drag	Move selected object on the XZ plane. On multi-selection: drags the entire group — relative positions preserved, single Undo step.
Shift + click	Multi-select (N objects) — for CSG, alignment
Left drag on empty zone	Box-select — draw a selection rectangle. Shift = add to selection.
Alt + left drag	Pan full 3D — drag horizontal → left/right (XZ camera-relative), drag vertical → up/down (Y)
Alt + right drag	Pan the grid + all objects — useful for large scenes
Right click + drag	Orbit camera around the scene
Middle click + drag	Pan camera
Scroll wheel	Zoom in / out
Single click on object	Select + show cotation mode — XYZ dimension handles, resize by dragging corners or top handle
Double-click on object	Switch to rotation mode — 3 Cura-style rings (X/Y/Z). Drag a ring to rotate. Single click returns to cotation mode.
Double-click on .gen object	Reopens the generator dialog pre-filled with current parameters — live edit in-place (Cubic/Cylind/Tore/Pipe/Gear/Screw/Nut/Sketch/CircularText)

⌨ Keyboard Shortcuts

Ctrl + Z	Undo — up to 200 levels
Ctrl + Y	Redo
Ctrl + D	Duplicate selection
Del / Backspace	Delete selection
Arrows ↑↓←→	Move object 1 mm (XZ plane, camera-relative)
Alt + ↑ / ↓	Move object up / down (Y axis)
Ctrl + A	Select all objects
Ctrl + C / Ctrl + V	Copy / Paste (offset +10mm X/Z) — geometry + transforms preserved
L	Show / hide 3D alignment handles
S	Enable / disable magnetic snap (0.001 / 0.01 / 0.1 / 0.5 / 1 mm) — toolbar buttons to set step
N	Toggle light / dark theme
1 · 2 · 3 · 4 · 5	Camera views: Perspective · Top · Front · Right · Reset
Esc	Deselect all / Cancel box-select / Close dialogs

🔷 3D Primitives — 18 watertight

Every primitive is closed and watertight — ready to slice, ready for boolean operations, no repair step needed.

Standard primitives (toolbox)
Cube	Box 20×20×20 mm — 6 flat faces
Sphere ◎	Configurable resolution 8–256 segs (slider in Properties) · export at 2× resolution, capped 512 · smooth shading built-in
Half-sphere ◑	Flat-capped hemisphere — same slider as sphere
Cylinder	64 segs display / 128 segs export
Cone	64 segs / 128 export
Pyramid ▲	4-sided pyramid — square base + triangular faces
RoofArc ⌒	Half-cylinder / vaulted roof — length W, radius H, closed caps
Tube ⊙	Hollow cylinder — outer radius Ro, inner radius Ri, height H. Parameters editable in Properties.
Lathe ⌀	Surface of revolution — 64 segs / 128 export · profile defined by spline points
3D Text ✏	Extruded text — 6 fonts (Helvetiker R/B, Optimer R/B, Gentilis R/B) · configurable depth, bevel
Wedge ▷	Right-angle bevel — 20mm base, triangular cross-section
Generator primitives (.gen — parametric, double-click to edit)
⌾ Cylind.Gen	Truncated cylinder with double chamfer — Rt, Rb, H, top/bottom chamfer 1–48 segs, N facets 12–128
✦☐ Cubic.Gen	Chamfered / rounded cube — W×H×D, chamfer radius, 1–48 segments
◎ Tore.Gen	Ultra-HD torus — ring R, tube r, N ring facets 12–256, M tube facets 6–128 — seamless
◑ ArcSphere.Gen	Spherical sector — full angle phi 1–360°, capped, correct shading at both poles
⌀ RevSolid.Gen	Revolved solid — arc angle 1–360°. Closed caps when angle < 360°.
🟰 Pipe.Gen	Hollow pipe — straight segments + tangent bends (radius R_bend, real tube-bending). No section twist along the path. Outer wall + inner wall + sealed caps.
⚙ Gear.Gen	ISO involute gears (20° pressure angle) — module 0.5–8 mm, straight / helical / herringbone. V-pulley and timing pulley. Configurable teeth, shaft bore.
🔩 Screw.Gen	Parametric screw ISO 68-1 (M2–M24) / ASME UNC·UNF — head Hex/CHC/None · Coarse/Fine/Custom/Plain · lead-in and lead-out · 32–96 radial facets. Double-click to re-edit.
⬡ Nut.Gen	Parametric nut ISO 4032/4033 · ASME B18.2.2 — M2–M24 / imperial UNC·UNF · ISO style 4032 / ISO 4033 Tall / Custom · optional 30° chamfer. Double-click to re-edit.
✏ Sketch.Gen	2D fullscreen sketcher — lines, circles, rectangles, arcs, Bézier. Extrude a closed contour into a solid. Trim tool, magnetic snap. Double-click to re-edit.
◠ CircularText.Gen	Curved 3D text on arc — arch (∩) or smile (∪) · arc angle 0–340° · font size, depth, spacing · 6 fonts. Double-click to re-edit.

📥 Import — STL · OBJ · 3MF · GLB · PLY · STEP

STL	Binary + ASCII — automatic centering, placed on floor
OBJ	Wavefront with vertex normals — compatible Blender, FreeCAD
3MF	Bambu Studio / PrusaSlicer format — per-object colors, multi-body
GLB	Binary glTF 2.0 — multi-part assembly and colors preserved, Draco-compressed files supported
PLY	Stanford polygon format — point clouds, scanned meshes
STEP	AP203 · AP214 · AP242 — see the dedicated section below. Also accepts `.stpz · .stpx · .stpxml · .p21`

🧩 STEP Import — assemblies, names and real colors

STEP is the exchange format of professional CAD. NASSCAD reads the real B-Rep geometry, not a mesh approximation — part names, assembly structure and colors come through as the author saved them.

What comes in
Protocols	AP203, AP214, AP242 — files from Fusion 360, SolidWorks, Inventor, CATIA, NX, Creo, FreeCAD, Onshape
Assemblies	Every part arrives as its own object, at its real position, under its real name. A 1200-part assembly gives 1200 named objects in the list.
🎨 Colors per part	The color the designer assigned to each part is applied on import.
🎨 Colors per face	A single part can carry several colors — a painted body with a bare machined face, a label on a housing, a two-tone casing. Each face keeps its own color. Requires the NASSCAD Engine companion (see Speed below): the in-browser engine does not expose per-face colors.
Which color wins	When a file gives a part one color and its faces another, the faces win — this is the STEP standard's own rule, and it is what FreeCAD, Fusion 360 and CAD Assistant do. Some exporters leave a stale color on the part itself; NASSCAD will not show it.
Color accuracy	Colors are displayed exactly as written in the file. Open the same file in FreeCAD or Fusion side by side — the shades match.
Units	The file's own unit is read and converted — millimetres, inches, metres.
Speed
⚡ NASSCAD Engine	The NASSCAD Engine companion reads STEP natively and in parallel on your machine — several times faster, and it is what delivers per-face colors and large assemblies. Detected automatically at import; nothing to configure. Recommended for any real CAD work.
In-browser fallback	Without the companion, STEP still opens with no install and no upload — but with two real limits, measured, not assumed: colors come per part only (the in-browser engine returns no per-face color at all), and large assemblies may produce no geometry. Files up to roughly 20 MB are comfortable; well beyond that, run the companion.
Instant re-import	A file you have already imported comes back immediately from the browser cache (up to 400 MB, oldest entries dropped first). Useful when iterating on a scene.
Very large files	With the companion, hundreds of MB are handled — the import is split and streamed, with live progress. A 350 MB assembly is normal work, not an edge case. In the browser alone, that class of file is out of reach.
Geometry quality
Automatic repair	Surfaces are stitched with progressively looser tolerance, small gaps are closed, and each body is checked for watertightness.
⚠ Non-manifold notice	Bodies that cannot be made watertight are reported after import (e.g. 2 non-manifold). They display normally — only boolean operations on them are restricted until repaired.
Smooth shading	Curved surfaces are smoothed while sharp edges stay sharp — no faceted look, no rounded-off corners.

📏 PMI & GD&T — manufacturing data from AP242

Modern AP242 files can carry the drawing information inside the 3D model: dimensions, datums and geometric tolerances. When a file has it, NASSCAD reads it and shows it — no 2D drawing needed.

Dimensions	Linear, angular and diameter dimensions with their values and units
Datums	Reference frames (A, B, C…) identified and listed
Geometric tolerances	Flatness, perpendicularity, position, cylindricity… — the tolerance type is decoded and named
Graphical annotations	Feature control frames and notes drawn in 3D, placed on the part where the author put them
PMI panel	Opens automatically when a file carries PMI — a readable list beside the model. Overlays follow their part when you move it.
⚠ Limits	PMI only appears if the file actually contains it — most AP203/AP214 files do not. On some files the numeric value of a geometric tolerance is not exposed and only its type is shown. Always check against the source drawing before manufacturing.

⚙ CSG Operations — Union · Subtract · Intersect

∪ Union	Merges N objects into one solid. Shift+click to select N objects.
− Subtract	Subtracts holes from solids. Automatic hole-mode detection.
∩ Intersect	Keeps only the volume common to all selected objects.
Hole Mode	Marks an object as a hole (transparent red). Union with a solid = automatic subtraction.
Progressive CSG	A coarse preview appears immediately, then the full-quality result replaces it silently in the background. The badge ⚡ Refining is shown in between. Sources look hidden during the first pass — that is normal.
Fast path	Objects that do not overlap are merged directly, without the boolean engine. Measured: 200 spheres (19M vertices) in ~2.6s.
🌳 Tree	Displays the CSG construction tree — Union(A, Subtract(B, C))…
↺ Re-run	Non-destructive — rebuilds the sources and replays the operation. Survives Save/Load and Undo/Redo.
↺↺ Deep Re-run	Replays the whole tree from the leaves in one go. Shown only when the tree is at least 2 levels deep. Change a source, press Deep, everything downstream follows.
CSG⚡ quality	Buttons 32 / 64 / 128 in the menubar — how finely curves are resolved during booleans. Default 128. Does not change the display or the export quality.
Workers	×4 / ×6 / ×8 in the menubar — how much work is dispatched in parallel. Applied immediately, no reload.

⌐ Fillet & Chamfer — real CAD edges

Toolbar button ⌐. Rounds or bevels the edges of a solid — the real operation a mechanical CAD package performs, including the blended corners where three edges meet.

◉ Round / ✦ Chamfer	Rounded fillet or straight bevel — switch at any time before applying
Radius R	0.1 – 50 mm, slider or numeric field
Segments	8 / 16 / 32 / 48 / 96 / 192 — smoothness of the rounded surface. 32 is a good default.
⬡ All edges	Fillets every edge of the object in one operation
🖱 Pick edges	Click an edge to select it — hold and drag across several edges to paint-select them. Click again to deselect. Then ⬡ Selected fillets only those; the rest stay sharp.
⬆ Top / ⬇ Bottom	One click adds every edge of the topmost or bottommost flat face — the two most common cases
Edge colors	■ convex · ■ concave · ■ hovered · ■ picked
⚠ If it fails	A radius larger than the local geometry allows will be refused — the operation is rejected rather than producing a broken solid. Reduce R, or pick fewer edges at once.

✏ Sketch.Gen — 2D Sketcher → Extruded Solid

Fullscreen 2D overlay. Draw a closed contour → Extrude → solid in the scene. Double-click a Sketch.Gen object to re-edit it in place.

Drawing tools
⟡ Select (S)	Pick and move entities. Click background to deselect.
╱ Line (L)	Click start, click end. Chain lines to form a polyline.
▭ Rectangle (R)	Click two corners — generates 4 connected segments.
○ Circle (C)	Click center, drag to set radius.
◜ Arc (A)	3-point arc: start → end → through-point.
∿ Bézier (B)	Cubic Bézier curve. Click start, drag controls.
Trim	Click a segment to trim it at its intersections.
Extrusion
H (mm)	Extrusion height — editable numeric field in top bar.
⤴ Extrude → Scene	Closed contour → watertight solid added to the 3D scene. Multi-body supported.
UI & shortcuts
F	Fit view to all entities
G	Toggle grid
T	Toggle light / dark theme inside sketcher
Del	Delete selected entity
Esc / ✕ Close	Exit sketcher and return to 3D view

◠ CircularText.Gen — Curved 3D Text

Shape	∩ arch (top arc) or ∪ smile (bottom arc)
Curve angle	0–340° arc sweep. Negative values = smile. 0 = straight text.
Parameters	Font size, extrusion depth, letter spacing, bevel — 6 fonts
Double-click	Re-opens the dialog pre-filled to edit text or curve live

🔄 Rotation Gizmo

Rotation mode	Double-click an object — 3 Cura-style rings: ■ Y (blue) · ■ X (green) · ■ Z (red). Drag a ring to rotate. Snap 15°. Single click exits to cotation mode.
Ring size	Constant on screen — the rings keep the same apparent size whatever the zoom, exactly like Cura Slicer.
Angle display	Live angle shown during the drag.

📐 Face Handles — Interactive Resize

Activate	Single-click an object to show 6 handles. Drag a handle to resize live. Undo-safe.
4 corner handles	XZ plane resize — change Width and Depth together, keeping the opposite corner anchored.
Top square ■	Y height handle — drag up/down to change object height.
Arrow ↑ (green)	Y lift/lower — moves object vertically. Floor-clamped at Y=0 (no underground).
↧ Drop to ground	Toolbar button — snaps selection bottom face to Y=0. Works on multi-select.
Live dimensions	XYZ labels updated in real time during the drag, rotation-aware.

🎛 Properties Panel

☀ Light	Directional light intensity — 0 (dark) to 2 (very bright). Default 0.7. Global, not per-object.
Color	Click the swatch to open the OS color picker. Also reachable via 🎨 Recolor.
Opacity	0 = transparent, 1 = opaque. Below 1 enables transparent rendering with correct depth sorting.
Solid / Hole	Toggle object mode. Hole = transparent red, auto-subtracted in CSG Union.
Pos / Rot / Dim	Direct numeric input. Pos Y = height of the bottom face above ground. Dim = real dimensions, rotation-aware.
◎ Sphere resolution	Slider 8–256 segs, always visible. Live rebuild. Export at 2× capped 512. The ceiling is set by geometric accuracy (7.5 µm chord error on a 100 mm sphere — finer than any SLA printer), not by the graphics card.
X-Ray mode	Toolbar button — all objects semi-transparent. Reveals hidden or interior geometry. Toggle anytime.

📐 Alignment

Activate	Shift+click ≥ 2 objects → 📐 Align button or key L — colored 3D handles appear. Click a handle = immediate alignment.
X Axis	Left · Center · Right
Y Axis	Floor · Center · Top
Z Axis	Front · Center · Back
Object snap	Alt+drag on an object — snaps face-to-face to the nearest object. Active when Snap is enabled.

↩ Undo / Redo

Ctrl+Z / Ctrl+Y	200 levels, persisted in the browser — they survive a heavy session without slowing it down.
Scope	Add, delete, move, scale, rotate, CSG, duplicate, import, .gen edit, thread insert. Every change is undoable.
CSG stays coherent	The construction tree is part of each undo step — Re-run still works after Ctrl+Z.
Auto-purge	Oldest steps dropped when the limit is reached. Cleared on new project or file load.

💾 Save and Export

Save	Exports a `.json` project — objects, positions, colors, CSG geometries and construction tree
Load	Reloads a NASSCAD `.json` project — restores the complete scene including generator parameters
Export STL Binary	Native slicer format (Cura, PrusaSlicer, Bambu) — Z-up. 4–5× more compact than ASCII. Quality: 128 / 256 / 512 segs
Export STL ASCII	Human-readable text — legacy tool compatibility
Export OBJ	Wavefront with normals — compatible Blender, FreeCAD
Export 3MF	Native format for Bambu Studio, PrusaSlicer, Cura — per-object colors, Z-up
Export GLB	Binary glTF 2.0 — colors and normals embedded. Draco-compressed variant available (≈ 4–8× smaller)
Export PLY	Stanford polygon format — for scanning or VFX pipelines
Export STEP AP242	B-Rep STEP — opens in Fusion 360, FreeCAD, Autodesk Viewer, Siemens NX
Export Section SVG/DXF	Horizontal cross-section at Y = N mm → 2D contour as SVG (Inkscape) or DXF (AutoCAD/LibreCAD). Cut height chosen in the dialog.
STL Quality	Buttons 128 / 256 / 512 in the menubar — curve segments at export. 128 is enough for a 0.4 mm FDM nozzle.
📂 IDB Projects	Named projects saved inside the browser — list, save, load, delete. Quota bar displayed.
📁 Folder	Opens the folder containing the NASSCAD file (desktop only)

⚡ NassScript — Integrated JS Console

Access	Menubar button ⚡ Script — opens the script editor
Execution	Runs JavaScript against the scene — create objects, run booleans, batch repetitive work. Supports `await`.
Shortcuts	Ctrl+Enter = Run · Tab = 2 spaces · Ctrl+↑/↓ = history (20 entries)
Example	`addPrimitive('cube'); nasLog('OK','done');`
⚠ Power tool	Scripts run with full access to the application. Never paste code you have not read.

💾 Memory

NASSCAD reserves its own memory block at startup. Size chosen via 💾 Pool: 512MB / 1GB / 1.5GB / 2GB in the menubar (default 512 MB). Unused geometry is reclaimed automatically.

512 MB (default)	Comfortable for most sessions
1 GB	Recommended for large scenes and big STEP assemblies
2 GB (max)	For the heaviest work — desktop builds make the best use of it
MEM gauge	Bar at bottom right. Hover for detail.
♻ Flush pool	Toolbar button — reclaims memory on demand and reports how much was freed.
Integrity check	Stored geometry is checksummed — silent corruption is detected on load rather than shown as a broken model.

⚠ Performance Limits

Display (WebGL — graphics card)
✅ Smooth	< 500 objects	< 3M vertices	No risk
⚠ Slow	500–1,000 objects	3–8M vertices	FPS drop
🔴 Risk	> 1,000 objects	> 8M vertices	Likely freeze
Boolean operations
✅ Fast	< 10,000 triangles/object (cube, cone, pyramid…)		< 1 second
⚠ Slow	10,000–50,000 triangles/object (sphere, half-sphere)		1–10 seconds
🔴 Very slow	> 50,000 triangles/object — threaded parts in CSG		> 30 seconds
Memory + Undo history
✅ Safe	< 150 complex objects, < 50 active undo levels		Gauge < 50%
🔴 Saturation	> 300 objects or very large CSG history		Red MEM gauge
Practical tips
· Threaded parts in CSG: work at CSG⚡ 32 segs, switch to 128 only for the final export · Box-select: drag on an empty zone to select a group — then drag any selected object to move the whole group (snap-aware, single Undo) · Deep Re-run: change the sources, press ↺↺ Deep, the whole tree recomputes on its own · Complex CSG: reduce simple groups with Union first, then subtract · Big STEP assemblies: run the NASSCAD Engine companion — it is what gives you per-face colors and files above ~20 MB, not just speed · MEM gauge > 70%: save the project and reload the page to free memory · STL 128 segs: enough for a 0.4 mm FDM nozzle (printer resolution > 0.2 mm)

✅ What NASSCAD Guarantees

Printable geometry	Every primitive and every generator produces a closed, watertight solid — checked, not assumed. What you export slices without repair.
Faithful colors	Imported colors match what the original CAD package shows, per part and per face.
Nothing leaves your machine	No account, no upload, no server. Files are read locally; the optional companion runs on your own computer and listens only to it.
Works offline	A single HTML file plus its companions. No CDN, no network needed once downloaded.
Nothing is destroyed	Boolean operations keep their construction tree — you can always go back, change a source, and replay.

🎬 Authors

NASSCAD V4.7.0 — August 2026
✍ NASSER Architect & Tester	CLIT · Electronics technician · 3D Maker Vision, direction, critical bug identification, quality standards, field testing, technology pivots.
🤖 Claude Developer	Artificial Intelligence · Anthropic Successive Claude models — native CSG engine, watertight primitives, STEP colour decoding verified against the file itself, surgical patches, systematic verification before delivery.
V4.7.0 highlights: native CSG engine (NASSCAD Engine companion, C++/multithreaded) · 18 watertight primitives · Sketch.Gen 2D sketcher · Screw.Gen & Nut.Gen (ISO / ASME) · Gear.Gen · Pipe.Gen · CircularText.Gen · real fillet & chamfer on picked or all edges · STEP AP203/214/242 import with per-part and per-face colours · PMI & GD&T reading · CSG construction tree with non-destructive Re-run · Undo/Redo 200 levels · Box-select · Face handles & rotation gizmo · X-Ray mode · Import STL/OBJ/3MF/GLB/PLY/STEP · Export STL/OBJ/3MF/GLB/PLY/STEP AP242/SVG/DXF · magnetic snap down to 0.001 mm · NassScript console

Third-party components — all local, zero CDN:
In the browser
· three.js (Mr.doob and contributors) — MIT — 3D WebGL rendering
· OpenCASCADE Technology (Open Cascade SAS) — LGPL 2.1 with exception — B-Rep CAD kernel: fillet/chamfer, STEP assembly, colour and PMI reading
· occt-import-js (Viktor Kovács) — MIT — browser bridge to OpenCASCADE for STEP import
· Draco (Google) — Apache 2.0 — mesh compression, glTF/GLB import and export
· helvetiker_regular / bold (MAGENTA Ltd, MgOpen Modata) — MgOpen License
· optimer_regular / bold (MAGENTA Ltd, MgOpen Cosmetica) — MgOpen License
· gentilis_regular / bold (J. Victor Gaultney / SIL International) — SIL OFL 1.1
· nasscad_logs.js (NassLab) — CC BY-NC 4.0 — structured logging module
In the NASSCAD Engine companion (optional, runs on your machine)
· OpenCASCADE Technology (Open Cascade SAS) — LGPL 2.1 with exception — native STEP reading and tessellation
· Manifold (Emmett Lalish and contributors) — Apache 2.0 — boolean CSG engine
· oneTBB (Intel / UXL Foundation) — Apache 2.0 — multithreading
· Clipper2 (Angus Johnson) — Boost Software License 1.0 — 2D polygon clipping, used by Manifold
· hwloc (Inria and the Open MPI project) — BSD 3-Clause — CPU topology detection, used by oneTBB

⚖ NASSCAD V4.7.0 License
© 2026 NassLab — Nasser, France
This software is distributed under the Creative Commons BY-NC 4.0 license:
· Personal and non-commercial use — free, redistribution allowed with attribution
· Commercial use — written agreement required from NassLab

No implied warranty. The author cannot be held liable for any damage resulting from the use of this software.