# Prop3D

`uLib::Vtk::Prop3D` is a bridge class that wraps VTK 3D representations (`vtkProp`, `vtkProp3D`) and integrates them into the `uLib` object model. It allows the framework to manage visual objects, synchronize them with underlying data models, and expose display-specific properties to the GUI.

## Inheritance
`uLib::Vtk::Prop3D` : `uLib::Object`

## Key Functionalities

### VTK Integration
The class provides access to the underlying VTK objects:
- `GetProp()`: Returns the `vtkProp`.
- `GetProxyProp()`: Returns the `vtkProp3D`.
- `GetParts()` / `GetProps()`: Returns `vtkPropCollection` for composite objects.

### Model-View Synchronization
`Prop3D` ensures that the visual representation stays in sync with the domain model:
- `Update()`: Synchronizes the VTK representation based on current internal state and properties. Should be called when model data changes.
- `SyncFromVtk()`: Updates internal state using data from the VTK representation (e.g., after user interaction via gizmos in the 3D view).
- `GetContent()`: Returns the `uLib::Object` that this `Prop3D` represents visually.

### Visual Appearance
- **Color & Opacity**: `SetColor(r, g, b)` and `SetOpacity(alpha)`.
- **Selection**: `SetSelectable(bool)` and `SetSelected(bool)` to manage interactivity and highlighting.
- **BBox/Scale**: `ShowBoundingBox(bool)` and `ShowScaleMeasures(bool)`.

### Rendering Modes
The rendering style can be controlled via the `Representation` enum:
- `Points`
- `Wireframe`
- `Surface`
- `SurfaceWithEdges`
- `Volume`
- `Outline`
- `Slice`

### Display Properties System
`Prop3D` implements a system to expose specific properties (often marked as `hrp` - human readable properties) to a property editor in the GUI.

- `GetDisplayProperties()`: Returns the list of properties registered for display.
- `RegisterDisplayProperty(uLib::PropertyBase*)`: Adds a property to the display list.
- `serialize_display(...)`: A virtual method that subclasses implement to define which properties should be exposed.

#### Activating Display Properties
To automatically populate the display properties list, the `ULIB_ACTIVATE_DISPLAY_PROPERTIES` macro should be called in the constructor. This triggers `serialize_display` using a `display_properties_archive`.

## Implementation Details
`Prop3D` uses the Pimpl idiom (via `Prop3DData *pd`) to hide VTK-specific implementation details and reduce header dependencies.