Prepare stage¶

Status: PROPOSED

Prepare is the planned stage in docs/ui/ui-plan.md:52–93,171–195. Every item is PROPOSED unless a row is explicitly HOW IT IS with a code citation.

Prepare makes the non-planar decision before the conventional demo-process controls. Slicer mode opens here. Simulator mode can enter Prepare, but sees a reduced loader and read-only mesh view.

flowchart LR
  L["Load model"] --> M["Mesh + plates + palette"]
  M --> NP["Enable and configure Non-Planar"]
  NP --> R["Detect or paint regions"]
  R --> P["Check Process values"]
  P --> S["Slice"]
  S --> T["DEMO TOOLPATH badge + Preview offer"]

Profiles¶

PROPOSED — three compact chips stay at the top of the sidebar:

Chip	What it selects	Honest source
Printer	Printer preset and clearance defaults	PROPOSED host JSON store; later additive `SetPrinterProfile`
Filament	Material used for analysis	PROPOSED picker over a real material-profile path; parsed metadata can show `(inferred)`
Process	Named projection onto the visible process and non-planar fields	PROPOSED host preset; an edited field shows a delta marker

The picker and persistence model are covered in Profiles.

Plate and model summary¶

PROPOSED — after a model loads, the plate area contains:

Element	Planned behavior	Status
Plate/object list	One row per plate/object; the selection becomes the target for painting and transforms	PROPOSED
Visibility controls	Show or hide a selected object	PROPOSED
Palette chips	One chip per 3MF palette entry	PROPOSED UI over existing palette queries
Object transform strip	Move, rotate, or scale the selected plate	PROPOSED additive `SetPlateTransform`; plates are read-only today
Mesh information	Plates, palette size, vertices, triangles, and unit	HOW IT IS — the Slicer already exposes `MeshInfoLabel` (`src/SlicerApp/MainWindow.axaml:69`) and fills it after loading (`src/SlicerApp/MainWindow.axaml.cs:234–238`)
Warp-grid summary	Analysis grid dimensions / risk summary	HOW IT IS — `WarpGridLabel` exists (`src/SlicerApp/MainWindow.axaml:70`) and is filled through `GetWarpGridInfo` / `GetWarpGridRisk` (`src/SlicerApp/MainWindow.axaml.cs:579–621`; `src/Nps.EngineHost/EngineSession.cs:505–527`)

The engine already exposes plate counts, per-plate triangle counts, palette colors, and model unit (src/Nps.EngineHost/NpsAbi.cs:294–322). The list, selection, visibility, and transform interactions remain PROPOSED.

Non-Planar panel¶

PROPOSED — this group is expanded by default and sits above Process. Turning it off disables dependent fields with the reason “Enable Non-Planar first.”

Field	User meaning	Honesty label
Enable	Generate the current demo path with non-planar Z variation	HOW IT IS — `SliceNonPlanar` binds `EnableNonPlanar` (`src/SlicerApp/MainWindow.axaml:47–50`), which becomes `NpsGcodeGenParams.enableNonPlanar` (`src/Nps.EngineHost/EngineSession.cs:336–352`)
Maximum surface angle	Eligibility limit, 0–75°	PROPOSED — requires `SetNonPlanarParams.maxSurfaceAngleDeg`
Maximum amplitude	Cap on Z deviation	PROPOSED — requires `SetNonPlanarParams.maxAmplitudeMm`
Thickness envelope	Layers across which the transition blends	PROPOSED — requires `SetNonPlanarParams.thicknessEnvelopeMm`
Collision clearance	Nozzle radius and gantry height pair	PROPOSED — requires `collisionRadiusMm` / `collisionHeightMm`
Detection mode	Auto, Paint, or Full	PROPOSED
Seam policy	Aligned, Nearest, Random, or Painted	PROPOSED
Detect regions	Run automatic region detection	PROPOSED additive region exports
Paint regions	Enter the viewport brush mode	PROPOSED UI state plus additive paint-stroke export
Region rows	Show auto/painted source, overrides, and profile deltas	PROPOSED

Note

Enable is the only non-planar field that affects generation today. Angle, amplitude, thickness, clearance, detection, seam policy, region detection, painting, and overrides must not be presented as working controls.

See Non-Planar controls for the complete field and workflow map.

Process group¶

The four conventional inputs stay visible and expanded below Non-Planar. They are not hidden behind a preset because they are the only numeric generation parameters the engine consumes today.

Control	Default	Current route	Status
Layer height	0.2 mm	`SliceParams.LayerHeight` → `GcodeGenOptions.LayerHeight` → `NpsGcodeGenParams.layerHeight`	HOW IT IS (`src/SlicerApp/SliceParams.cs:40,50–54,88–96`; `src/Nps.EngineHost/EngineSession.cs:341–352`)
Feedrate	1800 mm/min	`Feedrate` → `feedrate`	HOW IT IS (`src/SlicerApp/SliceParams.cs:41,57–61,88–96`; `src/Nps.EngineHost/EngineSession.cs:350`)
Volumetric flow scale	1.0	`VolumetricFlowScale` → `volumetricFlowScale`	HOW IT IS (`src/SlicerApp/SliceParams.cs:42,64–68,88–96`; `src/Nps.EngineHost/EngineSession.cs:345–350`)
Number of layers	5	`NumLayers` → `numLayers`	HOW IT IS (`src/SlicerApp/SliceParams.cs:44,78–82,88–96`; `src/Nps.EngineHost/EngineSession.cs:351`)

PROPOSED — Process becomes a named, collapsible group without changing those four working routes. Applying a process profile fills fields; editing a field adds a delta marker and makes an already-generated path dirty.

Load model and G-code¶

Action	Planned Prepare behavior	Honest current state
Load model	Open a general 3MF model picker through `LoadModelFromFileWithOptions`; retain the Benchy shortcut	PROPOSED picker. HOW IT IS — the button currently resolves the primary fixture and calls the load path (`src/SlicerApp/MainWindow.axaml.cs:190–241`); the options-aware ABI export exists (`src/Nps.EngineHost/NpsAbi.cs:254–258`) but has no production UI consumer.
Load G-code	Open text G-code or BGCODE and move directly to inspectable Preview/Simulate state	HOW IT IS — a picker already feeds `ParseGcode` / `ParseBgcode` (`src/SlicerApp/MainWindow.axaml.cs:272–372`; `src/Nps.EngineHost/EngineSession.cs:124–165`). Stage routing is PROPOSED.
File menu	Open Model, Open G-code, Export, Quit	PROPOSED; it mirrors the visible buttons rather than creating alternate behavior.

Loading external G-code is analysis input, not a generated session export. It clears the planned demo provenance and leaves Export disabled until a path is generated in-session.

Slice CTA¶

PROPOSED — Slice is promoted to the titlebar. It becomes Re-slice when settings differ from the last generated snapshot and is disabled with a reason when no model is loaded.

HOW IT IS — Apply / Regenerate already requires _modelLoaded, harvests the controls, and enters RunGenerate (src/SlicerApp/MainWindow.axaml.cs:244–263,394–456). That path calls GenerateDemoToolpath; it is not a production slicer (src/Nps.EngineHost/EngineSession.cs:330–390). The planned CTA preserves that honesty and sets the DEMO TOOLPATH badge.

There is no fake percentage. PROPOSED — while the synchronous call runs, the button shows busy and the status bar reports an indeterminate operation. A cancelable progress dialog is deferred until async slice exports and threading rules exist.

Empty and failure states¶

State	Planned message / action	Status
Prepare, no model	`Import a 3MF model to begin` + Load model	PROPOSED
Preview, no toolpath	`Slice to see the toolpath`	PROPOSED
Simulate, no toolpath	`No toolpath loaded` + Open G-code	PROPOSED
Simulator-mode Prepare	Loaders + read-only mesh info; Process collapsed with “configure in Slicer mode”	PROPOSED
Missing fixture / load error	Keep the stage, preserve an honest error in status and Activity	PROPOSED Activity surface over existing error reporting
ABI mismatch	Disable engine actions and explain the mismatch in the titlebar chip	PROPOSED presentation over the existing ABI check