# Metope — User Guide *A 2.5D relief painting studio: sculpt clay, paint pigment, fire glaze, add texture and glow — lit in real time under raking light, and exportable as a real height map / mesh for milling, printing and showing.* Metope is a single file: open `metope.html` in a browser (it runs from a web address on your iPad). No install. Your work persists in the browser and can be exported as portable files. *Last revised 2026-07-27, against the live app.* --- ## 1. The big idea — REGISTERS A piece in Metope is built from independent **registers**. Each reads the relief and the light: | Register | What it is | Where | |----------|-----------|-------| | **Form** | the actual height/depth (the clay) — the mill truth | a **shape tool** (Pad, Stylus, Knife, Coil, Rake, Drill, Extrude, Stamp…) | | **Pigment** | flat colour | **◉ Paint** toggle | | **Finish** | roughness · metalness (how it catches light) — pools with the relief | **◐ Glaze** toggle | | **Glow** | emissive (self-lit) — rides in the Glaze register | Glaze + Emissive slider | | **Texture** | painted micro-surface (hammered, crackle, marble, wood…) | **⊞ Texture** toggle | | **Region** | which face set this belongs to (a spatial mask) | **▦ Set** toggle | **How they combine (important):** the **shape tool** is a single choice (tap the active one again to turn it *off*). **Paint / Glaze / Texture / Set** are **independent toggles** — turn any of them on to add them to your stroke. So one stroke can be **Pad + Paint** (deposit clay *and* colour at once), **Pinch + Texture + Glaze**, **Stamp + Set** (the motif marks its own region), or — with the shape tool **off** — pure surface painting (Paint + Glaze + Texture, no carving). If nothing is on, the brush does nothing. The tool readout shows your current combo, e.g. "✎ stylus + ◉ paint". --- ## 2. Interface layout — the ATELIER The interface is a workbench you arrange yourself. Your piece fills the whole window; the controls live in three places: the **spine** (the cabinet — every section, one glyph each), the **tablets** (drawers you take out and pin where you work), and the **dock + radial palette** (the palette in your hand — what your next stroke will do). ### The spine (left edge) **Tap a spine glyph** to open that section as a floating **tablet**. Tap again to close. The glyphs are grouped by craft: - **look** — ◎ Navigator · ❖ Tools - **surface** — ✺ Light · ◐ Material · ⊞ Texture - **build up** — ⧉ Layers · ⬚ Face Sets · ✛ Scaffold - **block** — ∿ Depth · ▣ Canvas · ◫ Project **A glowing dot on a glyph** means that system is live — symmetry on, guide magnet on, paint/glaze/set registers engaged, ⊞ texture register on, a layer live… **↩ / ↪ at the foot of the spine** — undo / redo, always in reach. The **» button** beside them widens the spine so every glyph shows its **name** (« narrows it back). The **Μ monogram** at the top opens the **Interface** tablet. ### The tablets - **Drag a tablet by its title to place it — that pins it** (the ◈ turns into a gold ◆). Pinned tablets stay where you put them, across reloads. Unpinned tablets close by themselves when you open another. **Double-tap a title** to roll a tablet up to just its header. Your arrangement is remembered. - **Tools, compact** — the small **▪▪** button in the Tools tablet header switches the tool grid to icons only (hover a tool for its name); **▤** brings the names back. ### The dock and the radial palette The composition of your next stroke lives **in your hand**, not in a tablet. - **The dock** is a small floating pill with four buttons: **⇅ Invert** (touch-friendly "ALT") · **◎ Size** (press & drag sideways to scrub brush size) · **↕ Height** (press & drag to scrub brush height) · the gold **palette disk**. **Drag the ✥ grip** at its head to put the dock anywhere on screen; the position is remembered. - **The radial palette** — tap the gold disk (or **tap the Spacebar**, or press the disk and *flick* toward a wedge, Blender-style) and a ring of choices opens where your hand already is: **view** (shaded · height · normals · heat · matcap) · **◉ paint** · **◐ glaze** · **⊞ texture** · **▦ set** · **colour** (opens Material) · **tools** (every shape tool in one ring) · **display** (wire · grid · angle view · ortho/perspective). Registers stay open as you toggle them; picking a tool closes the ring. The centre shows your current combo — tap it to go back to the top ring, tap again to close. **Esc** closes it too. ### The rest of the screen - **Main viewport** — your piece, lit live. Always shows the real displaced surface. - **Corner mini-panel (the small square, in the Navigator tablet)** — a **navigator** in flat view, an **orientation gizmo** in 3D view (see §11). - **The Μ monogram** opens the **Interface** tablet: choose the **stone** (Basalt dark · Plaster gallery-light · Terracotta · Aegean) and the **metal** (gold · copper · celadon · lapis · marble — or **◉ follow brush**, where the whole interface takes on your current paint colour). **Backdrop** sets the viewport's own colour (or *match stone*), and **◍ Environment backdrop** puts the lighting environment itself behind the piece. **↺ Reset bench** restores the default layout. --- ## 3. Navigating the view **iPad (Pencil + finger model):** the Pencil **draws**, the finger **navigates** — never the reverse. - **1 finger** — rotate (in 3D/perspective) or pan (in flat/ortho) - **2 fingers** — pan - **pinch** — zoom - **2-finger tap** — undo · **3-finger tap** — redo **Desktop:** left-drag draws; right-drag or Space+**hold**-drag pans (ortho) / orbits (perspective); scroll zooms. A quick **tap** of Space (no drag) summons the radial palette at the cursor instead. **Flat vs 3D:** press **5** (or the ⊡/⊙ button) to toggle **Ortho** (straight-on, for precise painting) and **Perspective** (angled, to read the relief). **Home** fits/resets the view. *(**F** or **S** sets the brush size and **D** the brush height — see §6.)* --- ## 4. The tools (Tools tablet) Twenty shape tools. Each one's full description is in its tooltip; this is what they're *for*. **Deposit & incise** - **● Pad** — deposits a soft dome of clay (builds up). ALT = press a dimple in. Its cross-section is set by **Pad profile** (see §6). **Nib width** squashes the footprint into a chisel-edge ellipse held at a *fixed angle* (set by **Rotation °**) — broad-pen calligraphy in relief: strokes swell and thin as their direction crosses the nib. 100% = round. - **⌒ Coil** — a rope of clay that actually *coils*: twisted plies wind along it as it advances. Tool options: **Twist (mm/turn)** (0 = smooth rope); **Strands** 1–5 (1 = a single spiral ridge, like a solomonic column; 3 = classic rope); **Stretch (×)** (elongates the cord pattern into long lazy diagonals); **Wobble** (hand-rolled thickness variation); **⟳ Z / ⟲ S** twist direction, like real cordage (alternate S/Z on side-by-side ropes for a herringbone read); **⋈ Braid** (both ply systems cross at once: an interlocking plait/sennit). **Softness** sets how deeply the cord grooves cut. ALT presses the rope *into* the clay — with twist on, that's **cord-marking** (Jōmon). - **✎ Stylus** — incises a soft-shouldered channel with piled side-ridges (sgraffito). ALT = raised coil. - **⊿ Knife** — cuts a thin, sharp crease with crisp walls and *no* side-ridges. ALT = a sharp raised crest. **Blade Length** (tool option) is decoupled from Size: low = a short path-following nib that traces any curve cleanly; high = a long rigid blade that cuts straight and fans on tight curves. - **☰ Rake** — parallel tines (a clay comb). ALT = furrows↔ridges. Set the number of teeth (2–20) with the **Rake teeth** slider. - **⋀ Crease** — pinches the surface into a V-groove along the stroke (Pinch + Knife, directional): the fold spans the whole footprint, deepest at the centre. ALT raises a sharp V-ridge. **Push the clay about** - **≈ Rib** — the kidney scraper: blurs hard toward the local mean, *removing* detail and flattening the form. ALT sharpens. - **∿ Smooth** — gently rounds sharp edges and makes bumps subtler while keeping the forms (attenuates relief instead of flattening it). Scale = brush Size, so a big brush melts broad relief and a small one cleans fine noise. ALT = sharpen. - **⇝ Smear** — drags the surface sideways along the stroke, like pushing wet clay. ALT grabs harder. - **✥ Move** — grab and drag a broad area with soft falloff (ZBrush's Move): a whole neighbourhood eases along as one blob. Big form changes, not a thin streak like Smear. - **◣ Pinch** — draws the surrounding relief inward to the brush centre (sharpens ridges, pulls gaps shut). ALT spreads it outward. - **◌ Inflate** — swells existing forms outward (rounder, fuller); flat ground barely moves. **Roundness** (tool option) picks how spherically they swell — high = balloon-like, 0 = crests grow fastest and sharpen. ALT deflates. **Cut architecture** - **▭ Scrape** — an *oriented* flat cut along the drag direction: levels a rectangular facet to the height under the brush centre at stroke start. A clean architectural plane, not a stamped disc; **Rotation** angles the facet away from the literal drag. Optional **▭▨ Teeth** (with count and raggedness) tear the long edges into a rasped boundary. ALT scrapes down only. - **⌓ Moulding** — classical architectural cross-sections extruded along the stroke: **▭ Flat/Fillet · ╱ Splay · ◟ Cavetto · ◝ Ovolo · ◠ Torus**. Rotation angles it away from the drag. ALT recesses the same profile. Run it along a Line/Rect/Circle draw-shape for an instant frame — and pair it with Chatter on the same path for dentils or bead-and-reel on top. - **⋯ Chatter** — the tool rhythmically *skips* as you drag (ceramic chattering / the engraver's tremolo): a run of raised pearl beads every **Pitch** mm. Bite shape is your choice — **⋀ Pointy** (a pyramid), **◡ Rounded** (a gouge scoop), **▭ Square** (a flat-bottomed chisel bite). **Softness shapes the beat** (hard = spiky separate beads, soft = fat beads that nearly touch); **Spacing** sets how finely the rhythm is sampled. ALT = engraved bites inward. Along a Line or Circle draw-shape it lays instant classical borders. - **☀ Gnomon** — *draw with shadow.* Your stroke marks where shadow should **fall**; the brush raises a lit wall on the sun side of the line (key **Light 1**), its height auto-calibrated to the light's elevation and the view's depth so the wall's cast shadow covers exactly what you drew. It wants **low, raking light** — at noon no wall is tall enough (that's physics, not a bug). ALT = **engraved shadow**: a calibrated pit that shades itself. Move the light and the drawing dissolves — a mark that only exists in the light. - **⊛ Drill** — punches a hard round hole to an *exact* depth: the floor sits **Height (mm)** below where the surface stood at stroke start, no matter how long you dwell or how often the stroke recrosses itself. Drag to rout a clean flat-bottom channel. Set the depth past the material's thickness to pierce clean through — a **real hole** opens in the block: the red back panel is cut away with it, you see straight through, and **exports carry the opening as true watertight geometry**. **Softness = taper**: 0 = straight bore, 1 = a conical countersink V. **Tilt (°)** angles the bore from vertical: the mouth stretches into an ellipse and the floor ramps down along the drag direction (steer it with **Rotation °**), the classical *trapano* scoop that holds shadow. ALT = the matching **peg**: a flat-top boss/dowel, always vertical (a leaning peg would be an overhang, which a relief cannot hold) — holes and pegs pair like mortise and tenon. - **⬆ Extrude** — Drill's opposite: **lifts the surface under the stroke as a clean layer**. Everything the brush covers rises by *exactly* **Height (mm)** — the existing modelling rides up intact on the new plateau — with a die-straight wall at the stroke's edge (**Softness** feathers it; the mesh rebuild gives the wall real geometry a moment after you lift the pen). One stroke = one lift; finish the stroke and stroke again to stack another layer. With a **face set** active, a single swipe lifts exactly that silhouette. ALT = the matching **flat-floored recess**, a counterbore. **Press a shape in** - **❂ Imprint** — drag-stamps an imported/primitive shape's depth along the stroke. - **◆ Stamp** — single press of that shape (drag to position, release to place). **Whole-surface buttons** (bottom of the Tool block) - **≈ Relax Mesh** — relax the **whole** surface at once: smooths ragged walls and fine bumps everywhere while keeping the big forms. Tap again to relax more (undoable). *(For local smoothing use the **∿ Smooth** brush.)* - **⬡ Rebuild Mesh** — re-tessellates the preview mesh so it follows the relief properly: vertices flow into steep, detailed areas, and **near-vertical steps become real walls** — a tall plateau or a stamped edge gets true vertical sides instead of smeared polygons. The wall's outline is **rim-smoothed** as it's built, at several scales at once, so a curved or diagonal edge comes out as a smooth curve instead of a pixel staircase — in the viewport *and* in every export — while genuine sharp corners (a rectangle set, opus-sectile tiles, brick/grout) stay exactly crisp. This happens **automatically a moment after every carving stroke** (and after undo/redo), so you rarely need the button; press it for the extra-dense version before showing work. *(While a stroke is in progress the surface under the brush shows the simple stretched preview — it snaps to clean walls when you lift the pen.)* ### The Model Stamp window (Imprint & Stamp) Choosing **❂ Imprint** or **◆ Stamp** opens the **Model Stamp** window — where you pick the *thing* you're pressing into the clay (the "press plate"). Whatever you stage here, **◆ Stamp** lays down once and **❂ Imprint** drag-stamps repeatedly along a stroke. A strip at the top remembers everything you've brought into this canvas — tap to re-stage, × to forget. **Source** — three kinds: - **Primitives** — Sphere, Box, Cone, Cylinder, Torus, Icosahedron. **Drag in the preview to orbit**; the depth seen *from that angle* is what gets pressed (wheel to zoom). - **⬆ Import model** — load your own 3D file: **.glb / .gltf / .obj / .stl**. Same orbit-to-choose-the-angle workflow. (Materials are ignored — only the shape's depth matters.) The bake is **auto-levelled**: the silhouette edge presses flush with the surface and the nearest point uses your full Height, whatever the angle. - **Detail** — how much of the Height budget goes to the model's *surface modelling* rather than its gross front-to-back form. On an in-the-round sculpture (a head, a figure) the nose-to-ear depth otherwise eats everything and the carved detail presses invisibly shallow. 0 = honest depth map; ~0.5 = form gently compressed, modelling boosted; 1 = detail-dominant, like a chased surface. - **🖼 Image → relief** — turn a flat picture into relief. **Brightness becomes height** (light = raised, dark = recessed). Controls: - **🧠 AI Depth** — estimate *true* depth from the photo (Marigold via fal.ai) instead of using brightness as height — much better for faces, objects and scenes with their own lighting. Needs a network connection and a fal.ai key; it only fetches when you tap it. - **▁ Level background flush** — level the picture's dominant background tone flush with the canvas, so a stamped photo embosses its *subject* instead of pressing the whole rectangle up as a slab. On by default. - **✂ Remove Background** — AI cut-out (fal.ai): the background presses nothing at all. - **⊘ Cut out background** — press only the opaque pixels, of a transparent PNG or of the AI cutout above. - **Flatten light · Smooth · Contrast · ⇅ Invert height** — remove the picture's overall tonal gradient, soften grain, deepen separation, flip light↔high. **The press takes the shape of whatever you import** — a rectangular image presses a rectangle, a transparent PNG presses its cut-out shape, a 3D model presses its silhouette. There is **no circular bound**, and **Softness** feathers that real outline. The **cursor mirrors the imported shape** so you see exactly what will land and where. Everything else comes from the **Brush** block: **Size (mm)** = footprint, **Height (mm)** = how deep/proud it presses, **Rotation** = spin the motif, **Softness** = edge feather. **Grid + Snap** apply, so stamps can land on a regular lattice. *Saving:* the relief you press **is** baked into the height map and saved with your project; the staged source is remembered per canvas in the library strip. --- ## 5. Modifiers - **ALT** (desktop) or **hold the ⇅ Invert button** (iPad — one in the Tools tablet, one on the dock) = the *opposite* of the current tool (dome↔dimple, incise↔raise, pool↔ridge, texture paint↔erase). Tap the button to lock it; hold for momentary. - **SHIFT** = quick Rib (smooth) without switching tools. --- ## 6. Brush settings (Tools tablet, lower half) - **Size (mm)** — footprint, in real millimetres. **Set it interactively:** press **F** or **S** and move the pointer (a ring previews the size; **click**/**Enter** to set, **Esc** to cancel); on iPad **press & drag the ◎ Size button** on the dock sideways to scrub it live. - **Height (mm)** — how deep/tall the brush works (also the flow rate for Paint/Glaze/Texture). Press **D** to set it interactively, or drag the **↕** button on the dock. - **Stabilize** — lag/smoothing of the stroke (0 = direct, higher = steadier). - **Strength** — 0 = no effect, 1 = full. Scales *every* brush: carve depth, smooth / smear / pinch / inflate amount. - **Pen pressure →** two toggles choose what the Apple Pencil's pressure drives, within the Strength setting: **Depth** (default on) — press harder to carve deeper / paint stronger; **Size** (optional) — press harder for a bigger footprint. Mouse and finger are always full strength. *(Like the other brush settings, these follow **Shared / Per Tool**.)* - **Softness (edge)** — soft vs crisp stroke shoulders, for the current tool **and** for ◉ Paint. Default (0.5) and up = the feathered edge; drag toward 0 to harden it into a crisp disc for clean colour blocking. - **Spacing (% of Size)** — dab step as a percentage of brush diameter, so it scales with Size automatically. Below ~50% dabs overlap into a continuous stroke; above 100% is a deliberately dotted stroke. - **Scatter (mm)** — random per-dab jitter. - **Jitter (strength)** — random per-dab strength variation: handmade facture instead of machine-even marks. Affects everything the stroke lays down (form, paint, glaze); pairs beautifully with **Scatter**, and gives **Chatter** pearls an organic unevenness. - **Rotation (°)** — fixed rotation for stamp/imprint tiles, the Pad nib, the Scrape facet, the Moulding profile and the Drill tilt. - **Pad profile** — the Pad's cross-section: ◠ Round · ∪ U · ⋁ V · ▭ Square · 🖼 **Image** (load a PNG; its brightness becomes the brush-tip height). - **⇅ Invert** — same as ALT. - **Shared / Per Tool** (header button) — whether every tool shares one brush setting or each remembers its own. *Tool-specific options* (Rake teeth, Chatter pitch and bite shape, Coil twist/strands/braid, Knife blade length, Inflate roundness, Scrape teeth, Moulding profile, Drill tilt) appear at the bottom of the Brush block while that tool is selected. --- ## 7. Material tablet — "painting with materials" **The preview row** at the top — two balls and the colour well: - **PIGMENT** — your colour at a matte finish (the hue you'll paint). - **FIRED** — the same colour with the actual roughness/metalness/glow (how it'll look glazed). - **COL** — the brush colour well (used by Paint, and as Glaze's tint). **Controls:** - **Roughness / Metalness** — the finish that **Glaze** lays down (and what the FIRED ball shows). - **Emissive (glow)** — self-lit glow, applied by Glaze. Try high values for molten looks. - **Finish character** (a *whole-piece* finish in how the work is lit; leave at 0 for the plain look): - **Clearcoat (wet)** — a second, sharp specular sheen, like a clear glaze or varnish. Shows on the **glossy** areas and leaves matte stone matte. - **Subsurface (wax)** — light wraps softly round the forms and warms at grazing angles, the way wax, jade or thin marble glows. - **Granulation** — pigment settles **darker in the micro-recesses** of the carving, like watercolour granulation or a dirty wash sinking into the texture. - **Flow ↔ Flat** — 1 = finish pools in the relief (the magic); 0 = even finish everywhere. - **Glaze colour** — the glaze's **own** colour, independent of the Paint colour. So a piece can be terracotta pigment with a celadon or cobalt glaze pooled into the recesses. - **Colour tint** — how much the glaze tints with that glaze colour (0 = clear/finish only). - **⚛ React to metal** — reactive glaze: the glaze only adheres where the surface is **already metallic** — like gold leaf catching on sized areas. Paint metal first, then glaze freely; it self-masks. - **⬆ Bake Paint → Relief** — *raised enamel / slip-trailing:* raises real relief wherever you've painted or glazed (reads colour coverage). Tap again to build it up; the colour is kept. Paint your motif **selectively** first. - **⬛ Paint All** — floods the whole block with the current colour + finish + glow. - **Material library** — collapsible categories of little material balls; tap a category name to roll it open or shut (it remembers). **My Materials** first (your saved swatches), then **Metals** (Gold/Silver/Copper/Bronze/Iron) · **Stone** (Marble/Limestone/Basalt/Jade) · **Ceramic** (Terracotta/Celadon/Raku Black/Porcelain) · **Organic** (Wax/Bone) · **Glow** (Ember) · **Textured** (below). Tap a ball to load its colour+finish+glow into the brush. **+ Save** stores the current material into My Materials (long-press to delete). - **Textured sets** (category "Textured") — **Carrara Marble · Travertine · Oak Grain · Hammered Bronze**: real *image-texture* materials. Pick one and **Paint** — the stroke lays the stone's actual veining/pores/grain (colour + finish + micro-relief together), tiled at true size via the **Map tile (mm)** slider. Two extra sliders shape the active set: **set relief** (how strongly its normal catches light) and **set roughness** bias. **⬛ Fill Set with Material** floods a whole face-set region with it. The micro-relief goes into the ⊞ register, so **⬇ Bake Texture → Form** makes it real, millable height. Picking any plain material switches the set off. - **＋ Import set** — import a PBR image set from your device: an **albedo/colour** map (required) plus optional **roughness** and **height** maps (named `*_albedo`, `*_rough`, `*_height`…), **or a single .zip exported from the Marble / Wood studios** (Lapideo). It lands in a **My Sets** library category with a thumbnail and paints exactly like the built-ins. Imported sets are saved on the device. - **⬇ Export set** — saves the **active** set (yours *or* a built-in) as a `.zip` of albedo / roughness / height PNGs + a recipe, to back up or share. - **Matcaps** (foot of the tablet) — the material-ball images used by the **Matcap (form only)** view. **＋ Load** adds your own (select several at once), click a ball to use it, right-click to remove, **⇅ Flip** fixes one that was lit from below. **Workflow example:** paint a terracotta field → switch to Glaze, pick a celadon **glaze colour**, Roughness low → glaze over the relief (a glossy celadon pools in the hollows over the clay). Tap **Gold**, ALT-Glaze the ridges → gold leaf on the peaks. Pick **Crackle** texture + ⊞ → craze the glaze. Or: paint a motif, then **⬆ Bake Paint → Relief** to lift it into raised enamel. --- ## 8. Texture tablet — the pattern studio (⊞) Pick a **primitive** and shape it with the recipe sliders; paint it with the **⊞ Texture** register (ALT erases). **The primitives:** Hammer (hammered dents) · Crackle (crackle-glaze veins) · Brushed · Woven · Grain / stipple · Waves (meandering bands) · Cells (voronoi) · Stripes / fluting · Dots · Brick (running bond) · Noise · **Marble** (calcite veining) · **Wood** (growth-ring grain) · **Spiral** (bands winding out from a centre). Two variants sit beside them: **⋔ Cracks** turns Cells into thin crack/vein lines along the cell boundaries, and **◎ Concentric Circles** turns Spiral's arms into rings. **The recipe:** **Scale** (fineness) · **Rotation** · **Ratio** (stretch the cells — turn dots into grain) · **Contrast** · **Warp + Warp scale** (organic distortion) · **Jitter** (irregularity — cell scatter, stripe wobble, mortar width, grain wander) · **Depth** (mm of light-catching relief) · **Roughness**. Three primitives get two extra sliders of their own: Marble gets **Vein Angle** and **Vein Complexity**, Wood gets **Cathedral ↔ Straight** and **Ring Sharpness**, Spiral gets **Epicenters** and **Centre Spread**. **The sliders edit the pattern in place — strokes you've ALREADY painted with it restyle live.** Want two variants? **＋ Save texture** stores the recipe in **My Textures** (swatch grid, long-press to delete); loading a saved texture gives it its own slot so it can live next to the original. - **⇅ Invert All Patterns** — a master flip of every pattern's peaks/valleys and rough/smooth at once, in every slot, painted or not. - **⬇ Bake Texture → Form** — carves the painted texture into the real (millable) height and folds its roughness into the material permanently, then clears the live pattern. Each painted pattern bakes at **its own** Depth (mm); **Bake Softness** blurs the result if you want it worn or printer-friendly. With the **▦ Set** register on, the baked pattern also becomes the active face-set's region — and with **▦ Split Sets by Height: ON**, one texture yields **two** face sets: the pattern's raised areas go to the active set and its recesses to an auto-created *"(name) low"* companion (brick faces vs. grout, in one bake). The **Hi/Lo Threshold** slider moves the dividing height. - **✕ Clear Texture** — the opposite of Bake: discards the live ⊞ register across the whole block, carving nothing. Colour and finish untouched. Undoable. --- ## 9. Layers tablet — smart masks & smart materials Up to **12 non-destructive layers**, each a material (colour + finish, and optionally its own relief) revealed by a **mask**. Build a piece the way you would in Substance Painter. - **＋ Add layer**, pick its **colour / roughness / metalness / opacity**, and a **Blend** mode for how its colour combines with what's below: **Normal** replaces, **Multiply** darkens (grime, shadowed dirt), **Add** / **Screen** lighten (glow, worn highlights), **Overlay** boosts contrast. (Blend affects colour only — roughness/metalness always replace where the mask reveals.) - **Fill with** — instead of a flat colour, a layer can fill with a whole **material set** (marble, bronze, your imported sets) revealed through its mask, previewing its **real** maps live. - **Relief (mm, −3…+3)** — where the mask shows, the *displayed* surface rises or sinks: material sets shape it with their own height map, flat layers raise a plateau (painted gilding that stands proud). The two registers stay honest — the real millable height is untouched while layers are live; **⬇ Flatten** presses the relief in for real. - **🖌 Paint mask** — turn it on and brush on the canvas to *reveal* the layer where you paint; hold **⇅ Invert** to erase. (Mask painting ignores the sculpt tools and paint/glaze registers.) Undoable, and **Clear painted mask** resets it. - **Smart mask** — instead of (or on top of) hand-painting, let the layer **find the relief itself**: **Cavities** pools into the recesses (verdigris in the carving) · **Ridges** catches worn highlights on edges · **Slope** picks steep faces · **Depth** picks a height band · **AO** settles broad grime and weathering into wider hollows · **Face set** masks a chosen region · **Fill** covers everything evenly (a base layer to paint into). Smart masks **re-flow as you carve** — change the relief and they follow, including relief a layer above made. **⇅ Invert generator** flips any of them. - Layers show in **both** flat and 3D views, stack in order (top of the list = top of the stack), and each has a **👁 show/hide** and **▲▼** to move it up or down. **⬇ Flatten all layers** bakes the whole stack — colour, finish **and** relief — into the real registers and clears it (fully undoable: the stack comes back). Saved with the project, painted masks included. - **＋ Save stack as Smart material** — store the whole stack (recipes + smart-mask settings + relief) as a named preset. One tap re-applies the entire recipe onto a different piece; the smart masks re-derive on whatever relief they land on, which is what makes a stack portable. *Exports read the real height, so **flatten** if you want a layer's relief to mill or print.* --- ## 10. Light & Environment **Light tablet.** Up to **3 raking lights**, each casting its own shadow: - **The orb** — each light is a coloured dot. Drag a dot (or tap empty space) to aim the selected light. Edge = grazing/raking; centre = head-on. - **Chips (1 2 3 · ＋ · ×)** — select a light, **＋** add (up to 3), **×** remove the selected one. - **Brightness** — the selected light's intensity (0–3). **Light colour** — its colour (great with Emissive and metals). - **Ambient occlusion** — darkens crevices by how much the surrounding relief rises above each point, computed live from the height field. 0 = off. - **Relief** — **Normal depth** (how pronounced shallow relief reads) and **Shadow** (raking-shadow strength). **Environment (HDRI).** A gallery of skies — **Neutral · Day · Studio · Sunset · Night · Foundry** (ember glow from below — try it with bronze and emissive). **⬆ Load HDRI (.hdr)** adds your own; they're kept with a thumbnail and survive reloads (× removes one). The last-used environment comes back on reload. Plus **IBL strength**, **Exposure**, **Env rotation**, **Reflection** (metallic/glossy pop — brightens the environment reflection and sharpens the highlight) and **Punch** (extra contrast on top of the ACES filmic curve; 1 = neutral, matching the exported GLB). Lights and environment persist across reloads and are saved with the project. --- ## 11. Navigator & the scaffold **Navigator tablet** — the mini-panel, the view modes, and ↩ Undo · ↪ Redo · ⊡ Fit. - **View modes**: **Shaded PBR** (the real look) · **Height map** (grey) · **Normals** · **Heatmap** (depth/CNC danger) · **Matcap (form only)**. - **Matcap (form only)** — read the **relief alone**, with no colour or material — perfect for judging form. Its balls live at the foot of the Material tablet (§7). - **The corner mini-panel:** in **Ortho** it's a **navigator** — the whole block with an orange rectangle marking your zoomed region; drag or tap to pan there. In **Perspective** it's an **orientation gizmo** — a wireframe of the block (front face highlighted) that rotates with your view; drag it to orbit. - **⬡ Wire** (W) — wireframe overlay on the 3D mesh. **Angle View** — a floating second camera you can orbit and zoom independently. **Scaffold tablet** — symmetry, grids, draw shapes and guides, all in one drawer. - **Symmetry**: **↔ X** (mirror left/right), **↕ Y** (top/bottom), **✲ Radial** (N-fold around the centre — set **Count** 2–16). Toggle any combination and **every stroke is mirrored live**; dashed axes mark the mirror lines. Beautiful with a **circular canvas** for rosettes and mandalas (X + Radial = double the spokes). *(Face-set region painting is left un-mirrored on purpose.)* - **▦ Grid** (G) — overlay grid in flat view. **Six kinds** (picking one turns the grid on): **▦ mm** (the placement grid — the only one Snap uses; set its size) · **⌗ Thirds** · **φ Golden** sections · **৩ Spiral** (golden spiral — tap again to turn it through its 4 orientations) · **⟀ Persp** (one-point perspective: a horizon and rays from a **vanishing point** you place with the Vanish X/Y sliders, even off-canvas) · **╳ Diag** (diagonal armature). Set the grid's **colour** and **line width** here too; the rulers appear with the grid. - **⊹ Snap** — snap Stamp/Imprint placement (and tiled Imprint dabs) to the mm grid; draw-shape endpoints, guide placement and face-set Rect/Circle snap the same way. Turning Snap on shows the grid. - **Draw shape**: **✐ Free · ╱ Line · ▭ Rect · ◯ Circle.** With a shape mode on, a single press-drag-release lays the **active brush along that ideal path** — so *Line + Stylus* = a perfectly straight carved groove, *Circle + Pad* = a ring of domes, *Circle + Moulding* = a turned frame, *Circle + Paint* = a precise painted circle. Circle is **centre-out**. **⊾ Constrain** locks lines to 0/45/90°, circles to perfectly round, rectangles to square. - **Guides** — persistent **rulers and compass circles** that *freehand* strokes magnetize to. Unlike Draw shape (one stroke = one ideal path), a guide **stays on the canvas** and you can run **many strokes along it** — borders, concentric rings, hand-drawn fluting. - **Place:** tap **╱ Ruler** then drag start → end; tap **◎ Compass** then drag centre → radius. The button disarms after each placement. - **✎ Curve — sketch your own guide.** Tap it, then *draw* a flowing line. Your sketch is gently smoothed and becomes a persistent guide — rough in a vine scroll, a wave border, a drapery fold *once*, then carve it deep with the Stylus, glaze it, and drybrush its ridges, each stroke locking onto the same line. - **∟ Poly — tap out corner points.** Made for the **Greek-key meander**: arm it, then tap each corner; a rubber band with a live **mm readout** previews the next segment. **Finish** by tapping the last point again, pressing **Enter**, or tapping the button again; **Esc** cancels. With **⊾ Constrain** every segment locks to 0/45/90°; with Grid + Snap, corners land on intersections. You can pan and zoom between taps for long borders. - **🧲 Magnet** (M) — a freehand stroke that **starts within the Magnet range** (mm slider) of a guide **locks onto it for the whole stroke**: every dab lands exactly on the line, the stroke direction follows the guide (rake tines align), and a ruler stroke **stops dead at the ruler's ends** like a real straightedge. Strokes that start farther away stay completely free. A small tether-dot shows where you'd latch before you press. - **✥ Edit** — drag the square handles (ruler ends · compass centre/radius · every poly corner), tap the red **✕** to delete one. **✕ Clear** removes all. **👁 Show** hides them (hidden guides never pull). - Guides are remembered across reloads **and saved inside projects / .metope files**. They work with Stabilize and with Symmetry (one compass + Radial = instant rosette rings). --- ## 12. Regions, depth, and the machine ### Face Sets (⬚) Hand-painted regions that act as a **spatial mask for every brush** (form, paint, glaze, texture). - **▦ Paint Regions** — the switch: with it on, *anything* you apply marks the active set — any tool's stroke marks its footprint, Stamp/Imprint mark the motif's exact silhouette, and ⬇ Bake Texture marks the baked pattern. (Same switch as the **▦ Set** register in the palette.) **＋ New Set** always gets a fresh, distinct colour. Rename (double-click), recolour (swatch), **L** = lock, **H** = hide, **×** = delete. - **Mask** (On/Off) — when **On**, locked/hidden sets are **frozen**, protected from *every* brush including re-painting regions. So: paint a set, **lock** it, Mask On, then paint the next set right up against it without clobbering it. **Isolate** edits only the active set. **◧ Show Tint** tints the regions in the view. - **The region modes — ▭ Rect · ○ Circle · 🪣 Flood Fill — take over the canvas while armed**, so you can't accidentally carve while placing a shape. They're mutually exclusive, and picking any sculpting tool unpresses them. - **▭ Rect / ○ Circle** — draw an exact rectangle or circle into the active set: **press** (corner / centre), **drag** (a gold dashed ghost with a live mm readout), **release**. Hard-edged, respecting Lock/Mask, undoable, snapping to the grid. The mode stays armed so you can draw shape after shape (frames, borders, opus-sectile grids). - **🪣 Flood Fill Region** — click and the whole **contiguous** same-region blob under the cursor becomes the active set. Stops at existing boundaries; never crosses into a locked/hidden set. - **≋ Smooth Edges** — a **brush** that rounds off a face-set boundary **where you drag it**. Face-set membership is an exact index, so its edge is a hard raster boundary — round staircase steps or a scalloped freehand edge into a clean curve *before* Extruding it. - **⬛ Fill Set with Material** — flood the active set's region with the current brush material (colour + finish + glow) in one tap, and remember it on the set. **◐ Blur border** feathers the fill so adjacent filled regions blend instead of meeting at a hard line (Isolate keeps it crisp and contained). - **⊞ Fill Set with Texture** — flood the region with the current Texture-tablet pattern (relief + roughness only; colour untouched). **✕ Clear Set Texture** removes it again. - **⬆ Extrude Set** — lift the active set's **exact silhouette** as one clean layer: every texel rises by the Brush **Height (mm)**, existing modelling intact, with true walls at the border. Tap again to stack another layer; **⇅ Invert** presses the matching flat recess. *The workflow*: stamp a motif with the **▦ Set** register on, then tap Extrude Set — the motif rises as a solid step. **The step's walls belong to the set too**: they tint and hide with it, and in the print panel's **Sets** mode they print in that same filament, so an extruded set comes out one solid colour, sides included. - **≈ Smooth Set Edges** — rounds off **every** face-set boundary in the canvas in one tap. Worth a tap or two *before* Extrude Set: a jagged region edge otherwise carries straight through into a jagged wall. *(Pushed hard on a very thin set, smoothing will shrink it — same as any edge-smoothing tool. Stop tapping once it looks right.)* - **Opus sectile** — each set carries a **stone** dropdown (— · Carrara · Porphyry · Onyx · Verde · Portoro · Rosso · Pavonazzetto). Give a set its own stone and its unpainted texels render as that solid stone, live and carve-responsive — a porphyry rota inlaid in a Carrara or clay ground. Two sets of the same stone are different slabs, not clones. Paint still covers everything, exactly like the block itself. (First 16 sets; side walls show the base block.) *(Face sets are the **spatial** mask — "only here". The **Depth Mask** is a different axis — "only at this depth". They stack.)* ### Depth tablet (∿) - **⤡ Resize** — change the block's **total depth** without deleting carving: drag the ceiling/floor handles on the histogram inward to thin or outward (into the margins) to deepen, up to 2×. **Apply Depth** commits the new canvas depth. - **⤢ Expand** — stretch the relief's contrast to fill the current block's depth (clips outside the window). Doesn't change the block. - **Depth Mask** — restrict brushing to a depth band (From/To mm); toggle On/Off. - **CNC floor** — a depth limit shown as a contour; carving can't go below it (mill-bed safety). - **CNC ceiling** — a height limit; building/raising can't rise above it (stay within stock thickness — dig away and rebuild without ever exceeding your board's real width). Measured as height above the bed. **◧ Show Lines** hides the contour overlay while leaving both limits fully enforced. - **The Brush Height (mm) slider tracks whichever limit is active** for the current tool + Invert state: switch a carving tool to Invert (or a building tool out of it) and the slider's range live-updates to the headroom that direction can actually reach. The clamp happens per-stroke regardless — this just keeps the number honest. - **CNC Check** — will a router actually be able to carve this? Note: this checks **bit reachability**, not sculptural undercuts — a heightfield can't hold a true overhang, so there is no undercut for Metope to have. - **⚠ Bit Reach** — tints **magenta** every spot a flat-end bit of the chosen **Bit ⌀** cannot reach: slots, pockets and drilled holes narrower than the bit. Pure overlay; your sculpt is untouched. - **⚙ CNC Preview** — shows what the machine would really produce: unreachable zones collapse to the machined surface (tinted **amber**, distinct from Bit Reach's magenta). Toggle off to return to your sculpt — nothing is changed underneath. **Exports are WYSIWYG**: while CNC Preview is ON, every export (STL, GLB, print 3MF, ZIP) carries the machined surface instead of the sculpt. - **Bit ⌀ (mm)** — the router bit diameter (0.5–12mm, persists). Smaller bit = reaches more. Judged with a slightly-wider-than-round bit footprint (an octagon), so it errs cautious, never optimistic. Recomputes by itself after each stroke while a toggle is on. --- ## 13. The block — size, shape, material ### Size (Canvas tablet) Set **W × H × D** (mm). Two ways to apply: - **⤢ Resize (keep art)** — grows or crops the block **without losing your work**. All carving, paint, materials, face-sets and layers are kept; newly-added area is blank clay. Use the **anchor** (3×3 grid) to choose which edge or corner of your artwork stays fixed. A dashed frame previews the new bounds (amber = growing, red = cropping); cropping asks to confirm. - **New blank slab** — discards everything and starts fresh at this size (confirm prompt). The block starts as a low clay slab so you **build up** as well as carve. **↺ Clear canvas** erases all carving, paint and materials back to a blank block (undoable). ### Shape — not just rectangles - **□ Rect** — the full rectangle (default). - **○ Circle** — set **Radius X / Y** and **Centre X / Y** (mm), then **↺ Apply Shape**. A circular (or oval) plate. - **◇ Poly** — **click the canvas to drop vertices** and build a custom outline (following Grid & Snap and X/Y Symmetry — turn on Symmetry and drag any vertex, including the default rectangle's corners, to move its mirror image with it); **✎ Edit** to drag a vertex (right-click one to remove it), **◡ Smooth vertex** to round a selected corner into a curve, **↺ Apply** to rebuild. Every polygon edit is undoable. Everything — sculpt, paint, glaze, texture, and the export — is **clipped to the shape**; outside the outline is empty. It's a *live clip*, so switching back to **Rect** restores the full canvas. The shape is saved with the project. *(Tip: a circle/oval is capped to fit inside the current block — to make a bigger medallion, Resize the block larger first.)* ### Material — what the uncarved block is made of Display only: the height map, the brushes and every export are untouched, and paint covers the block exactly as it covers plain clay. But it changes everything about how the work *reads*. - **Plain (clay)** — the default. - **Plywood ¾″** — **baltic birch 13-ply** (the classic CNC blank, 13 equal ~1.4mm plies) or **hardwood-core 7-ply** (thin face veneers over five thick crossbands). True construction scale: carving crosses the veneers and exposes their contour rings with thin dark glue lines, the outer walls read as stripes, and a block deeper than one sheet becomes a glued stack with a heavier joint every 18mm. This is what the CNC job will actually look like. - **Hardwood (solid, flat-sawn)** — **Oak · Walnut · Cherry · Maple · Ebony**. Modelled as a real log: growth rings are cylinders around a pith that sits behind the back face and tilts slightly, so the face shows **cathedral flames** that wander along the board, and carving moves *toward* the log centre so the rings tighten and shift. - **Stone (solid)** — **Marble · bianco Carrara · Porphyry · imperial red · Onyx · giallo (banded honey) · Marble · verde antico · portoro (black & gold) · rosso Levanto · pavonazzetto**. Every stone is a true 3D field: veins are sheets in the solid, onyx bands are stacked laminae, breccias are 3D clasts with cement in the joints, porphyry is a crystal speckle. **Carving genuinely moves through the figure** — cut deeper and a band or a clast wanders — and the side walls show the same stone passing through, matching the face at the arris. - **🎲 New slab** — reroll the figure seed: same material, different veining / rings / crystals (face-set inlays too). Saved with the project, so a piece keeps its exact figure forever; a new project rolls a new slab. The block material bakes into the GLB/USDZ export too — laminate rings or marble figure on the carved surface, striped or veined side walls. --- ## 14. Saving, and getting it out **In-app projects** (Project tablet): - **💾 Save** — update the open project · **＋ Save As** — store a new one. - **📁 Projects…** — a gallery with thumbnails: **Load / Duplicate / Delete**. *Duplicate* is how you branch a good relief and explore variations. - These live inside this browser (IndexedDB). Reliable for active work, but **not** a permanent archive. **Portable files:** - **⬆ Export file** — downloads a single `.metope` file (on iPad: share sheet → Save to Files → your Dropbox). It carries everything — height, pigment, finish, texture, face sets, guides, the layer stack with its painted masks, the block seed. - **⬇ Import file** — opens a `.metope` back onto the canvas. A project captures everything: height, colour, finish, glow, texture, face sets, block size and material, depth mask, lighting, and a thumbnail. (Undo history is not saved.) **Fabrication & showing:** - **↓ Export ZIP** — the finished maps + mesh (height PNG, colour, material, normal, viewport, and a mesh) for fabrication. - **⬇ Export STL** — the relief as a binary STL solid with a base plate, for slicing and 3D printing. Pierced holes come through as real holes. - **⬇ GLB/USDZ (digital)** — the painted relief as a **digital sculpture**: displaced mesh + baked PBR (colour / roughness / metalness / emissive), with the block material baked into the textures and, with the ◍ Environment backdrop on, the environment carried along. This is the file to put in a wiki page or an AR viewer. - **⬇ 5-colour 3MF (print)** — a PrusaSlicer MMU segmentation `.3mf` for the **Prusa XL**, up to 5 tools. Only the **painted relief** is written into the file; walls, base and infill are left to the slicer — so in PrusaSlicer set Infill, Perimeter and Solid-infill extruder to your **Body** number. Four ways to decide which colour goes to which tool: - **Target** — map each painted colour to the **nearest loaded filament** (perceptual OKLab). Paint freely, print with the spools you have. - **Auto** — extract 5 representative colours from the painting (median cut). - **Layers** — bind each paint *layer* to a tool exactly, no quantisation (base + the bottom 4 layers). - **Sets** — bind each *face set* to a tool exactly, no quantisation. Base set → the Body extruder; sets 1–4 → extruders 2–5. Regions print regardless of paint, so mark them with ▦ Paint Regions. **This is the reliable path for hard-edged polychrome.** - The **preview** below shows the quantised hard 5-colour regions — what actually prints. Click it to refresh. --- ## 15. Keyboard shortcuts | Key | Action | |-----|--------| | **Space** (tap) | radial palette at the cursor | | **Space** (hold) | pan (ortho) / orbit (perspective) | | **5** | toggle Ortho / Perspective | | **W** | wireframe · **G** | grid | | **M** | guide magnet on/off | | **F** or **S** | interactive brush **size** (move to size, click/Enter to set, Esc to cancel) | | **D** | interactive brush **height** (drag vertically) | | **Home** | fit / reset view | | **Shift** (hold) | quick smooth (Rib) | | **Alt** (hold) | invert (opposite of the tool) | | **Cmd/Ctrl+Z** | undo · **Cmd+Shift+Z** or **Ctrl+Y** | redo | | **Enter** | finish a Poly guide · **Esc** | cancel a guide, close the Projects / Model Stamp panel, close the palette | --- *Touchstone: this is a painter's clay — real media feel + honest, fabricable depth, lit in real time. Have fun.*