ReferenceIntersector

Public Class

A class used to find and return elements that intersect a ray created from an origin point and direction.

Inheritance Hierarchy

System.Object
Autodesk.Revit.DB.ReferenceIntersector

Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)

Syntax

public class ReferenceIntersector : IDisposable

The ReferenceIntersector type exposes the following members.

Constructors

Name

Description

Public Method
ReferenceIntersector(View3D)

Constructs a ReferenceIntersector which is set to return intersections from all elements and representing all reference target types.

Public Method
ReferenceIntersector(ElementFilter, FindReferenceTarget, View3D)

Constructs a ReferenceIntersector which is set to return intersections from any element which passes an input filter.

Public Method
ReferenceIntersector(ElementId, FindReferenceTarget, View3D)

Constructs a ReferenceIntersector which is set to return intersections from a single target element only.

Public Method
ReferenceIntersector(ICollection.ElementId., FindReferenceTarget, View3D)

Constructs a ReferenceIntersector which is set to return intersections from any of a set of target elements.

Properties

Name

Description

Public Property
FindReferencesInRevitLinks

Determines if references inside Revit Links should be found.

Public Property
IsValidObject

Specifies whether the .NET object represents a valid Revit entity.

Public Property

TargetType

The type of reference to find.

Public Property

ViewId

The id of the 3D view used for evaluation.

Methods

Name

Description

Public Method

Dispose

Releases all resources used by the ReferenceIntersector

Public Method

Equals

Determines whether the specified object is equal to the current object.
(Inherited from Object)

Public Method

Find

Projects a ray from the origin along the given direction, and returns all references from intersected elements which match the ReferenceIntersector’s criteria.

Public Method
FindNearest

Projects a ray from the origin along the given direction, and returns the nearest reference from intersected elements which match the ReferenceIntersector’s criteria.

Public Method

GetFilter

Gets the ElementFilter used in intersection testing.

Public Method

GetHashCode

Serves as the default hash function.
(Inherited from Object)

Public Method

GetTargetElementIds

Gets the set of ElementIds to test from in intersection testing.

Public Method

GetType

Gets the Type of the current instance.
(Inherited from Object)

Public Method

SetFilter

Sets the ElementFilter used in intersection testing.

Public Method

SetTargetElementIds

Sets the set of ElementIds to test from in intersection testing.

Public Method

ToString

Returns a string that represents the current object.
(Inherited from Object)

Remarks

An instance of this class can be constructed to return any 3D geometric element that intersects the ray created by the origin and direction, or to return a subset of elements based on filtering and flags. The caller can opt to filter the results using an ElementFilter, or by applying a specific list of acceptable elements. The caller can also specify the type of object to be returned, which might be whole elements, geometry objects, or a combination. In all cases the caller is required to supply a 3D view for evaluation; the view and visibility settings on the input view will determine if a particular element is returned (for example, hidden elements will never be returned by this tool, nor will elements whose geometry is outside the section box of the view).

The class is configured so that a single instance can be constructed and used for multiple evaluations of different rays. The results of the evaluation are not preserved between invocations on the same ReferenceIntersector.

The class also offers an option to return element results encountered in Revit Links. When the FindReferencesInRevitLinks flag is set, the results may include elements in the host document and in any RevitLinkInstance encountered, depending on the other flags set. See the remarks for FindReferencesInRevitLinks for details on how the flags affect the results obtained from links.

Example

public class RayProjection : IExternalCommand
{
    public Result Execute(ExternalCommandData revit, ref string message, ElementSet elements)
    {
        Document doc = revit.Application.ActiveUIDocument.Document;

        ICollection<ElementId> selectedIds = revit.Application.ActiveUIDocument.Selection.GetElementIds();

        // If skylight is selected, process it.
        FamilyInstance skylight = null;
        if (selectedIds.Count == 1)
        {
            foreach (ElementId id in selectedIds)
            {
                Element e = doc.GetElement(id);
                if (e is FamilyInstance)
                {
                    FamilyInstance instance = e as FamilyInstance;
                    bool isWindow = (instance.Category.BuiltInCategory == BuiltInCategory.OST_Windows);
                    bool isHostedByRoof = (instance.Host.Category.BuiltInCategory == BuiltInCategory.OST_Roofs);

                    if (isWindow && isHostedByRoof)
                    {
                        skylight = instance;
                    }
                }
            }
        }

        if (skylight == null)
        {
            message = "Please select one skylight.";
            return Result.Cancelled;
        }

        // Calculate the height
        Line line = CalculateLineAboveFloor(doc, skylight);

        // Create a model curve to show the distance
        Plane plane = Plane.CreateByNormalAndOrigin(new XYZ(1, 0, 0), line.GetEndPoint(0));
        SketchPlane sketchPlane = SketchPlane.Create(doc, plane);

        ModelCurve curve = doc.Create.NewModelCurve(line, sketchPlane);

        // Show a message with the length value
        TaskDialog.Show("Distance", "Distance to floor: " + String.Format("{0:f2}", line.Length));

        return Result.Succeeded;
    }

    /// <summary>
    /// Determines the line segment that connects the skylight to the nearest floor.
    /// </summary>
    /// <returns>The line segment.</returns>
    private Line CalculateLineAboveFloor(Document doc, FamilyInstance skylight)
    {
        // Find a 3D view to use for the ReferenceIntersector constructor
        FilteredElementCollector collector = new FilteredElementCollector(doc);
        Func<View3D, bool> isNotTemplate = v3 => !(v3.IsTemplate);
        View3D view3D = collector.OfClass(typeof(View3D)).Cast<View3D>().First<View3D>(isNotTemplate);

        // Use the center of the skylight bounding box as the start point.
        BoundingBoxXYZ box = skylight.get_BoundingBox(view3D);
        XYZ center = box.Min.Add(box.Max).Multiply(0.5);

        // Project in the negative Z direction down to the floor.
        XYZ rayDirection = new XYZ(0, 0, -1);

        ElementClassFilter filter = new ElementClassFilter(typeof(Floor));

        ReferenceIntersector refIntersector = new ReferenceIntersector(filter, FindReferenceTarget.Face, view3D);
        ReferenceWithContext referenceWithContext = refIntersector.FindNearest(center, rayDirection);

        Reference reference = referenceWithContext.GetReference();
        XYZ intersection = reference.GlobalPoint;

        // Create line segment from the start point and intersection point.
        Line result = Line.CreateBound(center, intersection);
        return result;
    }
}