Revit Selection Filter

Revit Selection Filter

Selection.PickObject takes an ISelectionFilter to decide what the user may pick. SelectionConfiguration (from Nice3point.Revit.Toolkit) builds that filter from two lambdas; you do not hand-roll a class. It drives an interactive pick and needs the Revit UI (RevitAPIUI).

When to use

• Restricting an interactive pick to a category, type, or geometry kind.

Workflow

Step 1: Configure the allowed elements and references

Allow.Element gates which elements are pickable; Allow.Reference gates which references (faces, edges, points). Set either or both — each returns the configuration and they chain — then pass configuration.Filter to the pick call.

var configuration = new SelectionConfiguration()
    .Allow.Element(element => element.Category.Id.AreEquals(BuiltInCategory.OST_Walls))
    .Allow.Reference((reference, position) => false);

var picked = uiDocument.Selection.PickObject(ObjectType.Element, configuration.Filter);

Step 2: Verify

Run the command and confirm only the intended elements or references highlight and accept a pick.

Validation

• [ ] The filter uses SelectionConfiguration, not a hand-rolled ISelectionFilter.
• [ ] Allow.Element/Allow.Reference express the rule with a lambda, not a new class.

Common Pitfalls

| Pitfall | Correct approach | |---------------------------------------------------|-----------------------------------------------------------| | A bespoke ISelectionFilter for a category check | Use SelectionConfiguration().Allow.Element(...). | | Filtering references with an element-only filter | Add Allow.Reference((reference, position) => ...). | | SelectionConfiguration not found | The Nice3point.Revit.Toolkit package is not referenced. |

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Nice3point
• Source: Nice3point/revit-skills
• License: MIT

Install and usage instructions live in the source repository linked above.