Overview
Clash Detection enables automated checking of models for collisions between components.
In addition to traditional model-based clash detection (model-to-model), element-based checks can also be performed. This allows for targeted checks such as the following:
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Structural shell versus HVAC
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Structural framework versus mechanical and electrical systems
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Checking components with specific attributes against one another
The results of the clash detection can then be accessed and analyzed in the overall model via the “Clashes” tab.
All project users can access the results.
Configuring Clash Detection
Only users with the BIM Coordinator role or higher can define and manage clash detection.
Open Configuration
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Open the Manage menu by clicking the gear icon
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Switch to the Configuration tab (exclamation mark)
There, existing collision definitions can be:
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executed
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edited
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deleted
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or created.
Define a New Collision Check
To create a new collision check:
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Click “Add Definition”
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A configuration window opens
First, define the general settings:
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Name of the collision check
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Group
(allows multiple checks to be run together, e.g., all structural checks)
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Tolerance
(defines the minimum distance at which a collision is detected)
Defining Collision Sets
A collision check is based on two groups of components:
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Collision Set A
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Collision Set B
Both sets are defined in the same way.
At least one field must be defined.
If multiple fields are filled in, they are treated as an AND condition.
Defining the Sets
The following criteria can be used:
Discipline
Specifies that all models of a specific discipline are to be checked.
Model
Limits the check to specific models.
This can be useful when, for example, checks are performed on a per-building basis.
Elements
Defines which components are to be checked.
Example:
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Check load-bearing components
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Exclude recesses
Structural Attributes
Here, components can be filtered based on their attributes.
Example:
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Attribute “Load-bearing”
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Value “Yes”
This ensures that only load-bearing components are included in the check.
Color Coding
Optionally, a custom color can be defined for displaying collisions. This applies to both bundles “A” and “B.”
Clash Detection Limitations
Note:
Clash detection only considers objects with an area greater than 1 m².
Very small elements are therefore not checked.
Clash Detection Ribbon
The clash detection ribbon contains the following functions:
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Search
Free-text search for clash definitions.
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Filters
Filters clash detection results based on specific criteria.
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Refresh
Updates the overview (but does not perform a clash detection).
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Run Groups
Runs all clash detections for a defined group.
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Manage Groups
Manage and define groups of clash detections.
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Add Definition
Creates a new clash detection.
Run Collision Check
Three options are available for each defined collision check:
- Run
Starts the selected collision check. - Edit
Opens the check's configuration. - Delete
Permanently removes the collision definition.
Note:
Collision checks are not updated automatically and must be started manually.
Viewing and Displaying Clash Results
The results of the clash detection can be viewed in the overall model via the “Clashes” tab.
There, the detected clashes can be analyzed and visualized.
Visualization of Collisions
Three display modes are available:
Select
The colliding components are selected.
Highlighting
The collision partners are highlighted in color.
Isolate
The conflicting components are displayed in isolation.
Only the affected components are shown.
Clash Reporting
You can export the results of the clash detection using the Reporting menu.
For example, the clash data can be:
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exported as a report
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or analyzed further in Power BI.
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Frequently Asked Questions (FAQ)
Why aren’t small objects detected in the clash detection check?
Objects with an area smaller than 1 m² are not included.
Who can configure clash detection?
Only users with the BIM Coordinator role or higher can define or modify clash detection.
Are clash detection checks updated automatically?
No. Clash detection checks must be started manually.