Exclude Model Objects from Clash

The Objects exclusions tab allows you to exclude specific model objects from automatic clash detection.

While you can turn off entire model for clash, object exclusions provide more granular control. You can exclude objects which don’t need clashing, objects which are less of a priority or objects which are duplicated across multiple models to reduce the number of clashes and improve clash performance.

Note: Object exclusions are only available on V2 coordination spaces, See the Coordination Space Versions help topic to learn more about V1 and V2 coordination spaces.

Object Exclusions Table

The Object exclusions table displays all object exclusions created for this coordination space.

The table includes the following information for each object exclusion:

You can search for object exclusion by name using the search field.

Create an Object Exclusion

You can create up to 50 object exclusions in a coordination space.

Note: Objects excluded from automatic clash detection are still visible, but aren't checked for clashes. They don't have clash highlighting applied in the viewer or in any clash issues previously created against them.
  1. Click Create object exclusion.

  2. Step 1 of 3 Select models

    Select the models whose objects you want to exclude from clash.

    Note: Only supported and turned on for automatic clash detection can be used to create a object exclusion.

  3. Click Next.

  4. Step 2 of 3 Exclude model objects

    The selected models will be loaded into the modal viewer. You can investigate these models and look for relevant properties and apply rules to exclude objects.

  5. Click Add a rule.

    Each rule-parts consists of a:

    • Property: Choose from the properties in your models. Supported types currently include text, numbers, and boolean properties.

    • Operator: The operators you can choose are dependent on the selected property's type as follows:

Property Operator Description
Text Is / is not Is is used to match a property to a specific value and is not where it doesn't match. Select values from the Value drop-down list. Selecting multiple values will filter for objects that meet any one of those values.
Contains / does not contain

The entered value is checked against the parameter value
Starts with:

Determines whether a property starts with a specific text string. This operator is useful for filtering large sets of data where members want to focus on a specific subset of records
Is empty / is not empty: Check whether a property has a value or not. The is empty operator returns true if the property doesn't have a value, and the is not empty operator returns true if the property has a value. Sometimes, "space values" (for example, blank or null values) are considered values for these operators, so they would still be considered not empty.
Numeric Equals / not equals (= or ≠) Compare two values and determine if they are the same (equals) or different (not equals).
Greater than / less than (< or >) Compare two values and determine if the first value is larger (greater than) or smaller (less than) than the second value.
Greater than or equal to / less than or equal to (≤ or ≥) Determine if the first value is larger than or equal to (greater than or equal to) or smaller than or equal to (less than or equal to) the second value.
Is empty / is not empty Check whether a property has a value or not. Is empty returns true if the property does not have a value, and is not empty returns true if the property has a value. Sometimes, "space values" (for example, blank or null values) are considered values for these operators, so they would still be considered not empty.
Boolean Is true

The Is true boolean filter operator is used to retrieve objects that have a true value in a boolean field. When this filter is applied, it will only include records where the boolean field is set to true.
Is false

The Is false boolean filter operator is used to retrieve objects that have a false value in a boolean field. When this filter is applied, it will only include records where the boolean field is set to false.
Is null The Is null boolean filter operator is used to retrieve objects where a particular field does not have any value or is empty (null). This filter is helpful when you want to find objects that lack a value in a specific field.
  1. Create your first rule part defining a property, operator, and value.

    For example, in the following image:

    • Property: Internal/Category (Revit Category)

    • Operator: is

    • Value Revit Pipes

      The queried objects will turn purple. These are the objects that will be excluded from the clash check.

      The other objects will be hidden (or ghosted), and you will not be able to select or interact with them. However, you can use viewer tools (such as right-clicking and selecting Show all objects) and the Model Tree to make the hidden objects visible again, so that you can select and investigate them. This may be helpful when creating more complex selections using multiple rules. 

  2. Click + to extend the rule by adding another rule part, if required. Adding more parts to the rule further narrows down the selected model objects to those that match all parts of the rule. 

  3. Click Add rule to add new rules.

    Multiple rules are joined by a logical operator (and/or). The logical operator defines whether a model object must match all of the rules, or any one of the rules. 

  4. Click Add a rule to join your rule to another.

  5. Choose between and/or. This selection will be applied to all rules in this view.

    Once a logical operator is selected between the first and second rule, the same operator will be applied by default to subsequent rules. Keep this in mind as you build out your rules.

  6. Click Next to move to the next step.

  7. Step 2 of 3 Review and name

    Review the objects that will be excluded from clash. If these need to be changed, click Back and edit your object exclusion.

  8. If your objects exclusions are correct, enter a Name for your object exclusion.

  9. Click Save.

Import Object Exclusions

You can import object exclusions from other coordination spaces in the same or other projects. This allows you to reuse object exclusions for consistency and use a standard configuration for your projects.

You can import object exclusions from coordination spaces with clash turned on in BIM 360 projects where you are a project administrator.

Note: The number of object exclusions you import plus the existing object exclusions in a coordination space can't exceed 50. For example, if your coordination space already has 37 object exclusions, you can only import 13 more.

Follow these steps to import object exclusions from another project or coordination space:

  1. In the Object exclusions tab, click Import.

    In the Import object exclusions dialog, you need to choose a project and coordination space within the selected project.

  2. Select your desired project.

    Note: Projects where you are not a project administrator will not display in the list.
  3. Choose the coordination space to import from.

    Note: Active and inactive coordination spaces are displayed. Coordination spaces with clash turned off are not displayed.
  4. Select the object exclusions that you want to import.

  5. Click Import.

    Imported object exclusions will retain the object exclusion name, rules, and be automatically Active. However, the object exclusions won't have any models added and therefore won't affect the clash check.

    Click an imported object exclusion to open Step 1 of 3 Select models and select models to apply for that object exclusion (detailed in Create an Object Exclusion section above). Once you've added models and worked through the steps, run the clash check again to apply them to the coordination space.

    Note: The name of an imported object exclusion will be appended with (1) if it has the same name as an existing object exclusion.

Manage Object Exclusions

In the object exclusion table, click the More menu to view the following options:

Edit an Object Exclusion

  1. Click Edit

  2. This launches Step 2 of 3 of the object exclusion creation process. It shows the previous rules in the side panel and highlighted in the viewer.

    Note: If there are now no models associated with the object exclusion (for example, the selected models were turned off or removed from the coordination space altogether), members will be taken to Step 1 instead to select models again. 
  3. Edit the object exclusion rules as required.

  4. Click Change models to select or deselect specific models to include in the object exclusion as required.

  5. Click Next to go to Step 3 of 3 and rename the object exclusion if desired.

  6. Click Save to save the object exclusion. The relevant details in the object exclusion table will update.

Deactivate or Reactivate an Object Exclusion

Delete an Object Exclusion

Examples Uses for Object Exclusions

Prioritizing based on object properties

When coordinating a project, it's common to break models down further by defining sets of objects and giving them a priority.

In these cases, object exclusions can be used to exclude lower priority objects from clash results to keep focus on higher priority items based on the construction programme.

For example, excluding objects like moveable furniture, hangers, or pipes less than a certain diameter provides focus on coordinating the larger, more critical items.

Removing duplicate geometry

When coordinating on a project, it's common for designers and sub-contractors to use other discipline models as a base or to link these models into their own. In some cases, this can cause duplicate geometry in a coordination space which will create redundant clashes.

For example, a structural engineer may link the architectural model into theirs to provide context on sheets published to Document Management. This could result in some of the structural engineer’s 3D views also containing architectural elements. As Model Coordination clashes all objects automatically, having two representations of the same object can cause redundant clashes and reduce performance. Turning off one of the representations, in this case removing architectural elements from the structural model, will reduce clash ‘noise’ and improve performance.