Skill: VTK Visualization Pipeline

This skill defines how to bridge domain objects with the VTK 3D visualization layer.

Context

Wrapper: Prop3D (wraps a vtkProp).
Mapping: Viewport maintains m_ObjectToProp3D for synchronization.
GUI Integration: QViewport handles Qt events and selection signals.

Implementation Patterns

1. Creating a Prop3D

A Prop3D should wrap a domain object and update its visual state when the object changes.

class MyProp3D : public Prop3D {
public:
    MyProp3D(MyObject* obj) : Prop3D(obj) {
        // Connect domain updates to visual refreshes
        uLib::Object::connect(obj, &Object::Updated, [this]() { this->SyncFromObject(); });
        
        // Expose properties to the VTK side-panel
        ULIB_ACTIVATE_DISPLAY_PROPERTIES(*this)
    }
    
    void SyncFromObject() {
        // Update VTK actors/mappers from MyObject's properties
    }
};

2. Display Properties

Use serialize_display to choose which properties of the domain object or the Prop3D itself are visible in the sliding "Display Properties" panel in gcompose.

void serialize_display(Archive::display_properties_archive &ar) {
    ar & boost::serialization::make_hrp("Opacity", m_Opacity);
    ar & boost::serialization::make_hrp("Wireframe", m_Wireframe);
}

3. Transformation Sync (TRS)

Always synchronize the object's trs (Translate, Rotate, Scale) with the VTK actor's user transform.

void UpdateTransform() {
    auto matrix = GetContent()->GetTransform().GetMatrix();
    m_Actor->SetUserMatrix(uLib::ToVtkMatrix(matrix));
}

Checklist

Does the Prop3D connect to the object's Updated() signal?
Are ULIB_ACTIVATE_DISPLAY_PROPERTIES and serialize_display implemented?
Is the transformation (TRS) correctly mapped to the VTK actor?

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