Multi-Level IFC Staging and Active Storey Switching

[chraibi]

Description

Currently, when an IFC file with multiple storeys is loaded, the user is forced to pick a single level via a modal before the import completes. Because JuPedSim is currently 2D-focused, this decision is permanent for the session, preventing users from exploring the building's layout or verifying they've selected the correct storey for simulation.

We need to implement a "Staging" workflow where all detected levels are loaded into memory, allowing the user to switch the active view before finalizing the simulation geometry.

Current Behavior

• IFC import triggers a "Select Building Storey" modal.
• Selecting a storey and clicking "Import" discards the data for all other levels.
• Switching levels requires a full re-import of the IFC file.

Expected Behavior

• Staged Loading: All IfcBuildingStorey entities from the IFC file should be parsed during initial load.
• Storey Switcher: A new UI element (e.g., a "Level" dropdown or stack selector) should appear in the main workspace.
• Dynamic View: Switching the level in the UI should immediately update the 2D workspace to render that specific storey's geometry (spaces, doors, obstacles) based on OMA IDS height sampling.
• Simulation Lock: Only when the user is satisfied with the selected level do they "Commit" to the simulation context, locking that level's geometry for the JuPedSim engine.

Technical Tasks

• Data Model Expansion:

• Update the IfcProject state to hold an array of storeys rather than a single active object.

• Map each storey to its respective elevation and geometric entities.

• Workspace Layering:

• Implement a filtering mechanism in the renderer that only draws elements associated with the activeStoreyId.

• Ensure that "Journeys" and "Agent Sources" are cleared or updated when switching levels to avoid cross-floor data pollution.

• UI Implementation:

• Add a Storey Selector (similar to the list in your screenshot) to the sidebar or top toolbar.

• Show a preview of the "Walking Height" sample for the selected level to ensure openings (doors) are correctly detected at that specific elevation.

Acceptance Criteria

1. User can import a multi-storey IFC and immediately see the "Keller" level.
2. User can use a dropdown to switch to "Erdgeschoss" and see the geometry update instantly without a re-import.
3. The simulation only runs on the currently visible level when the "Start Simulation" button is pressed.