[docs] 1.6.0: units, duplicate, touch tools, element box select, workspace, graph lists

- units.md (new, in the nav): the global setting, the typed suffixes, and the three
  things a unit deliberately does NOT change - stored values, the feel of a drag, and
  what your peers see
- controls.md: selecting without a keyboard (the touch cluster and the Multi-select
  mode), a Duplicating section with a table of what a copy brings, and numeric fields
  now covering node/shader/animation cards plus typed units
- mesh-editing.md: Shift/Ctrl-drag box select in all three element modes
- saving.md: what a restore brings back, and why a plain reload starts clean
- node-system.md + shader-graph.md: the Flows / Shaders list in the left pane
- module-sdk.md: registerPostEffect and registerPostBackend, including why post is a
  separate registry from shader (an Effect is not a Material) and what a peer without
  the module sees

Built with --strict.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: AlexZ005

docs/controls.md

@@ -18,6 +18,7 @@ How to move the camera, select and transform objects, and find every keyboard sh
 - **Shift+click** adds or removes objects from a multi-selection (the last-picked object is the primary).
 - **Shift+drag** on empty space draws a box-select marquee.
 - **Ctrl+A** selects everything in the scene. Inside a mesh editing session it keeps its other meaning — select every face, edge or vertex — so the two never collide.
+- **Ctrl+D** duplicates the selection — see [Duplicating](#duplicating) for what a copy brings with it.
 - Selecting an object **locks it for other peers** (one lock per person); a locked object shows who holds it, and its right-click menu offers **Request control** to ask for a handover.
 
 ### What double-click does
@@ -33,6 +34,43 @@ An object scaled — or animated — down to almost nothing has no surface left
 !!! note
     At *exactly* zero scale the viewport click does not reach it yet; select it from the object list instead. That one is a known gap.
 
+### Selecting without a keyboard
+
+On a phone or tablet there is no <kbd>Shift</kbd> to hold and no right-click, so the same
+two gestures are available as a **mode**. *Settings ▸ Interface ▸ Touch tools* puts round
+**Undo**, **Redo** and **Multi-select** buttons beside the logo — on by default on phones
+and narrow windows.
+
+With **Multi-select** on:
+
+- a **tap adds** to the selection instead of replacing it, and
+- a **drag on empty space** draws the box-select marquee.
+
+It works the same inside a mesh editing session, on vertices, edges and faces. Everything
+else already has a touch path: long-press the viewport for the right-click menu, and the
+**+** button opens the same create menu.
+
+### Duplicating
+
+**Ctrl+D** (or right-click ▸ *Duplicate*) makes a working copy. A copy is a copy of
+everything that belongs to the object, not just its shape:
+
+| Comes along | |
+|---|---|
+| geometry, transform, children | always |
+| material and its texture slots | always, as its own detached copy |
+| physics, origin, camera settings | always |
+| **animation clips** | yes — the copy plays its own |
+| **object flow graph** | yes, with fresh node ids |
+| **shader graph** | yes — otherwise the copy would render frozen |
+
+An embedded **Object Flow** node inside a copied graph keeps pointing at the object it
+referenced. Re-aiming it at the copy is a decision only you can make, so it is left alone.
+
+Each of the last three can be switched off in *Settings ▸ Scene ▸ Duplicate* if you would
+rather a copy came out bare. An object that inherits the **scene default** shader keeps
+inheriting it — it does not get a private snapshot.
+
 ### Editing a multi-selection
 
 The properties panel edits **everything you have selected**, not just the last object you clicked. Change a colour, a material, a shadow flag or a physics setting and it applies to the whole set as a **single undo step**; a row whose objects disagree shows a dash until you set it.
@@ -67,6 +105,13 @@ The origin travels with the object: it replicates, saves, undoes, and is baked i
 
 Every number in the app is the same control: **drag** it to scrub, or **type** into it for live updates. <kbd>↑</kbd>/<kbd>↓</kbd> step by one unit — hold <kbd>Ctrl</kbd> for ×10, <kbd>Shift</kbd> for ×100 — and <kbd>Esc</kbd> reverts what you typed.
 
+That includes the numbers inside **node editor cards**, **shader nodes** and the
+**animation window** — dragging one of those scrubs the value without dragging the card.
+Scrubbing an animation key or a shader parameter is **one undo step**, not one per pixel.
+
+Fields that hold a distance or an angle also accept a typed **unit** (`12cm`, `4in`,
+`90deg`) — see [Units](units.md).
+
 ### Floating windows
 
 The toolboxes, the Explorer, the flow and animation windows and the panels all behave the same way: drag the header to move, drag the bottom-right corner to resize. A window can never be sized past the edge of the screen — the resize corner always stays reachable — and **double-clicking** the corner resets it to its default size while leaving it where you parked it. Size and position are remembered per window.

docs/mesh-editing.md

@@ -44,6 +44,7 @@ Each mode remembers its own selection, so you can hop between them without losin
 ### Selecting
 
 - **Click** an element to select it; **Ctrl+click** adds to the selection.
+- **Shift+drag** or **Ctrl+drag** draws a **box** — every vertex, edge or face inside it joins the selection. Works in all three element modes, and a box always takes whole faces (never half a quad). An empty box changes nothing, so a stray drag cannot wipe your work.
 - Selection **commands** appear as words in the *Select* row — they change what is picked, never the geometry:
 
 | Command | Modes | What it picks |

docs/module-sdk.md

@@ -106,6 +106,43 @@ api.registerFrameTask((time) => { /* every frame, synced seconds */ });
 api.registerMenu('Open my panel', () => { /* button on your manager card */ });
 ```
 
+#### registerPostEffect
+
+The [scene look](post-processing.md) stack is a registry too, so a module can add an
+effect a user can then add to the scene like any built-in one:
+
+```js
+api.registerPostEffect('bloomier', {
+	label: 'Bloomier',
+	group: 'camera',
+	params: [{ name: 'amount', type: 'number', default: 0.5, min: 0, max: 2 }],
+	make: (params, ctx) => new SomeEffect({ intensity: params.amount })
+});
+```
+
+Your kind is **namespaced** to your module, so two modules cannot collide. If your
+module is later disabled — or the scene is opened by someone who never installed it —
+the authored effect is **kept in the stack and skipped**, not deleted, and it starts
+working again the moment the module is back. That is deliberately the same behaviour in
+both cases: a peer without your module is in exactly the position of a user who turned
+it off.
+
+#### registerPostBackend
+
+For a whole *compiler* rather than a single effect — something that turns a shader
+description into an effect:
+
+```js
+api.registerPostBackend('fancy', 'Fancy compiler', (spec, ctx) => {
+	// spec: { fragment, uniforms, readsDepth, blend }  ->  return an Effect
+	return buildEffect(spec);
+});
+```
+
+This is separate from `registerShaderBackend` on purpose: a **shader** backend returns a
+*material* and a **post** backend returns an *effect*. An unknown key falls back to the
+built-in compiler rather than failing, and the document keeps the key it asked for.
+
 #### registerUnwrapBackend
 
 The [UV editor](uv-editor.md)'s **Unwrap** menu is a registry, so a module can add

docs/node-system.md

@@ -6,6 +6,17 @@ The Flow editor is a visual node graph that drives scene behavior — animation,
 
 Press <kbd>N</kbd> or use the flow icon in the bottom hud. The editor docks at the bottom (tabbed with the [Explorer](explorer.md) when both are open) and can be undocked to float.
 
+## The Flows list
+
+The left pane carries a collapsible **Flows** section above the node palette. It lists
+**Scene** at the root, then every object that actually has a flow graph of its own — it is a way
+to get *to* a graph, not a second object list, so an object with none is not in it.
+
+Click a row to select that object and switch the editor to its graph; click **Scene** to
+deselect and edit the scene-wide one. Drag the bar under the list to give it more room, and
+click the section header to collapse it. An entry whose object has been deleted is shown
+greyed out until the next save drops it.
+
 ## Adding nodes
 
 - **Palette** — the left sidebar lists every node by group with a filter box; drag a node onto the canvas. The palette can be collapsed or moved to the other side with the tabs on its edge.

docs/saving.md

@@ -4,6 +4,20 @@ How to save and load your work: the recommended `.tpscene` bundle, GLTF intercha
 
 The main menu (the logo button) has **Import** (bring 3D files into the scene), **Load** (open a saved file) and **Save**, with a format switch underneath: **GLTF | Scene** — and a **⚙** cog for export settings.
 
+## Where you left off
+
+Restoring a session — from the **Restore** prompt, from *auto-restore* in
+*Settings ▸ Scene*, or by loading a scene file — brings back more than the objects:
+
+- the **panels and windows** you had open, and which dock tab was in front,
+- what you had **selected**, and
+- an open **Edit Mesh** or **Sculpt** session, with the faces, edges or vertices you had
+  picked.
+
+A **plain page reload starts clean**, with everything closed. The workspace comes back
+when you ask for your scene back, not every time you refresh — and a scene whose author
+had nothing open will not close the panels *you* have open.
+
 ## Starting from a template
 
 **Menu ▸ Templates** opens a picker of ready-made scenes, in three tabs:

docs/shader-graph.md

@@ -29,6 +29,17 @@ There is no scope control to get wrong — **the selection is the control**:
 The header always says which. An object with its own graph ignores the scene default,
 so the order is *own graph → scene default → the object's real material*.
 
+## The Shaders list
+
+The left pane carries a collapsible **Shaders** section above the node palette. It lists
+**Scene** at the root, then every object that actually has a shader graph of its own — it is a way
+to get *to* a graph, not a second object list, so an object with none is not in it.
+
+Click a row to select that object and switch the editor to its graph; click **Scene** to
+deselect and edit the scene-wide one. Drag the bar under the list to give it more room, and
+click the section header to collapse it. An entry whose object has been deleted is shown
+greyed out until the next save drops it.
+
 ## The Surface node
 
 Every graph ends at one **Surface** node. Each of its inputs replaces one part of the

docs/units.md

@@ -0,0 +1,43 @@
+# Units
+
+The scene is metres and radians underneath, always. Units change how numbers are **shown to you and typed by you** — nothing else. That makes them a **local preference**: you can work in inches while a peer works in centimetres, and you are both editing the same scene.
+
+## Choosing your units
+
+*Settings ▸ Scene ▸ Units*:
+
+| Setting | Choices | Applies to |
+|---|---|---|
+| **Length** | m, cm, mm, in, ft | positions, the object origin, snapping steps, bevel width, merge distance |
+| **Angle** | degrees, radians | rotations and the rotation snap step |
+
+Fields that are not a distance or an angle are deliberately left alone — a roughness of 0.4, a duration in seconds, a texture pixel and a subdivision count are not measurements, and a unit picker on them would be noise.
+
+## Typing a unit
+
+You do not have to change the setting to enter a value in another unit. Any of these fields accepts a **suffix**, whatever is currently on display, and converts it as you type:
+
+| You type | You get |
+|---|---|
+| `12cm` | 0.12 m |
+| `250mm` | 0.25 m |
+| `4in` | 0.1016 m |
+| `1.5ft` | 0.4572 m |
+| `2'` | 0.6096 m |
+| `6"` | 0.1524 m |
+| `90deg` | a quarter turn |
+| `1.57rad` | the same quarter turn |
+
+A **bare number** means the unit on display. So in a centimetre field, `250` is 2.5 m; in a metre field, `250` is 250 m.
+
+## What does not change
+
+- **Stored values.** Switching from metres to centimetres re-renders the fields and moves nothing. A box at 1.5 m reads `150` in cm and is still at 1.5 m.
+- **The feel of a drag.** Scrubbing a field covers the same real distance in every unit — only the number under your cursor is written differently.
+- **What your peers see.** Units are never replicated and never saved into a scene, so opening someone's file does not change your setup, and yours does not change theirs.
+
+## Precision
+
+The number of decimals follows the unit, so the field keeps roughly the precision it had. A position showing `1.50` m shows `150` in centimetres — the same centimetre of control, just written without a fractional part. Inches and feet keep a decimal place for the same reason: a whole inch is a coarser step than a centimetre, so the field does not round that far.
+
+The arrow keys always step the **last visible digit**, with <kbd>Ctrl</kbd> for ten times that and <kbd>Shift</kbd> for a hundred — see [Numeric fields](controls.md#numeric-fields).

mkdocs.yml

@@ -4,6 +4,7 @@ nav:
   - Getting Started:
     - Welcome: index.md
     - Controls: controls.md
+    - Units: units.md
     - Connection: connection.md
   - Building:
     - Explorer: explorer.md