Overview
The "4D" in 4D Viewer stands for the addition of Time to 3D space.
By linking construction schedule tasks to 3D building model elements, the platform can simulate and animate the sequence of construction, demolition, and temporary works. This helps project teams plan schedules, spot logistical conflicts, and monitor site progress.
The Concept of Linking
A 4D model consists of two key components:
The 3D BIM Model: The physical representation of the structure, broken down into individual elements (e.g., columns, slabs, walls, pipes), each having a unique identifier.
The Programme (Schedule): A list of construction tasks, each defined by a description, Start Date, End Date, and status.
Linking is the association that connects a specific schedule task to one or more physical elements in the 3D model. For example, a task named "Pour Level 1 Slab" is linked to the 3D slab geometry for Level 1.
Setup of the 4D schedule is completed in ToBe Builder, and then the project linked to ToBe Twin by the ToBe Twin project admin, via the sensgrid admin settings menu.
Visualizing 4D Links (The Visibility Rules)
When you turn on the 4D BIM View on the map overlay, the viewer scans the schedule and adjusts the visibility of BIM elements based on the current timeline date.
The appearance of a linked BIM element depends on two factors: the Behavior Type of its associated task and the Status of that task on the chosen date.
Behavior Type | Task Status: Unstarted | Task Status: Active (In Progress) | Task Status: Completed |
Construction | Hidden | Dithered | Shown |
Demolition | Shown | Dithered | Hidden |
Temporary | Hidden | Shown | Hidden |
How to Animate construction sequence
Follow these steps to view the 4D simulation:
Activate the Project:
Open the Tobe Projects panel.
Click Activate on the target project to load the BIM model and schedule.
Enable 4D BIM View:
On the map overlay toolbar, click the 4D BIM View toggle button.
Note: Enabling this will hide elements of the BIM model that have not yet started construction according to the schedule's starting date.
Open the Tasks Timeline:
Click the Tasks Timeline button at the bottom of the left Work Panel.
The Gantt chart schedule will slide open at the bottom of the screen.
Navigate and Animate:
Drag the timeline playhead (blue slider) at the bottom.
As you drag the slider forward in time:
Completed elements will appear solid.
Elements in progress will appear semi-transparent (dithered).
Temporary formwork or scaffolding will appear during their active window and vanish when completed.
Demolished items will disappear as their tasks conclude.
Tip: If you select a task in the bottom Tasks Timeline, the map camera can automatically focus on the linked BIM elements, and the Selection Inspector will display the task details and link data.
Note: Users must be given permission to access the ToBe Builder project, in order for that project to appear in their Tobe Project panel. If a user does not have a valid ToBe Viewer licence, or if the user has not been added to that project, with at least a viewer level access, the project will not appear in there list, even if configured by the ToBe Twin admin.