How to split Duct by 2 picked point

[duongf7a]

Hi Everyone,

I'm trying to split Duct by 2 points from user, but I can only split duct when the user pick point from left to right. If the user pick 2 points from right to left I will get the error. Can anyone help me fix that.

Thank you.

The following is my code:

using Autodesk.Revit.Attributes;
using Nice3point.Revit.Toolkit.External;
using Autodesk.Revit.UI.Selection;
using Autodesk.Revit.DB.Mechanical;

namespace RevitAddIn2.Commands
{
/// <summary>
/// External command entry point invoked from the Revit interface
/// </summary>
[UsedImplicitly]
[Transaction(TransactionMode.Manual)]
public class DuctUpDownCmd : ExternalCommand
{
public override void Execute()
{
var ductRefer = UiDocument.Selection.PickObject(ObjectType.Element);

var ductElement = Document.GetElement(ductRefer);

var ductLocationCurve = ductElement.Location as LocationCurve;

var ductCurve = ductLocationCurve.Curve;

using (var tx = new Transaction(Document, "Break Duct"))
{
tx.Start();

var startRefPoint = UiDocument.Selection.PickObject(ObjectType.PointOnElement);

var insectStartPoint = ductCurve.Project(startRefPoint.GlobalPoint).XYZPoint;

var splitedDuctIdAtStartPoint = MechanicalUtils.BreakCurve(Document, ductRefer.ElementId, insectStartPoint);

var splitedDuctAtStartPoint = Document.GetElement(splitedDuctIdAtStartPoint);

var newDuctCurveLocation = splitedDuctAtStartPoint.Location as LocationCurve;

var newDuctCurve = newDuctCurveLocation.Curve;

var endRef = UiDocument.Selection.PickObject(ObjectType.PointOnElement);

var insectPtEnd = newDuctCurve.Project(endRef.GlobalPoint).XYZPoint;

var eleIdEnd = MechanicalUtils.BreakCurve(Document, splitedDuctIdAtStartPoint, insectPtEnd);

tx.Commit();
}

}

}
}

[Mohamed_Arshad · Accepted solution]

Hi @duongf7a 

    Duct split is based on the Duct draw direction, kindly refer the below code snippet and reference image for additional information.

Code Snippet

public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
{
    ///Get Document Properties
    UIDocument uiDoc = commandData.Application.ActiveUIDocument;
    Document doc = uiDoc.Document;

    ///Select Duct
    Reference ductRefer = uiDoc.Selection.PickObject(ObjectType.Element);

    ///Get Element from the Reference
    Element ductElement = doc.GetElement(ductRefer);

    ///Get Location Curve of the Duct
    LocationCurve ductLocationCurve = ductElement.Location as LocationCurve;

    ///Get Curve from Location Curve
    Curve ductCurve = ductLocationCurve.Curve;

    ///Get Duct Direction
    XYZ ductDir = ductCurve.GetEndPoint(1).Subtract(ductCurve.GetEndPoint(0)).Normalize();

    ///Get Break Point from the User
    Reference breakPoint_1_Ref = uiDoc.Selection.PickObject(ObjectType.PointOnElement);
    Reference breakPoint_2_Ref = uiDoc.Selection.PickObject(ObjectType.PointOnElement);

    ///Project Pick Point to the Duct Center Line
    XYZ breakPoint_1 = ductCurve.Project(breakPoint_1_Ref.GlobalPoint).XYZPoint;
    XYZ breakPoint_2 = ductCurve.Project(breakPoint_2_Ref.GlobalPoint).XYZPoint;

    using (Transaction breakDuct = new Transaction(doc,"Break Duct"))
    {
        breakDuct.Start();

        ///Break Duct using first Point
        ElementId splitDuctIdAtBreakPoint_1 = MechanicalUtils.BreakCurve(doc, ductRefer.ElementId, breakPoint_1);

        //Get Duct of the First Breaking
        Element splitDuctAtBreakPoint_1 = doc.GetElement(splitDuctIdAtBreakPoint_1);
        LocationCurve newDuctCurveLocation = splitDuctAtBreakPoint_1.Location as LocationCurve;
        Curve newDuctCurve = newDuctCurveLocation.Curve;

        ElementId secondSplitId = null;

        ///Get Start point of the duct
        XYZ pointPickDir = breakPoint_2.Subtract(breakPoint_1).Normalize();

        ///Direction Validation
        if (pointPickDir.IsAlmostEqualTo(ductDir, Math.Pow(10, -5)))
        {
            secondSplitId = ductElement.Id;
        }
        else
        {
            secondSplitId = splitDuctAtBreakPoint_1.Id;
        }

        ///Second Split
        ElementId secondElementId = MechanicalUtils.BreakCurve(doc, secondSplitId, breakPoint_2);

        breakDuct.Commit();

    }

    return Result.Succeeded;
}

Image Explanation

Output

Hope this will Helps 🙂

[jeremy_tammik]

In wonder whether any of these articles are of use to you, in addition to Mohamed's very kind and helpful suggestion?

• Split a Duct or Pipe
• Daylighting Extension and Splitting with Taps
• Split Pipe
• Splitting a Duct in More Depth
• Split Pipe Tutorial and Related Cases

[Mohamed_Arshad]

Hi @jeremy_tammik  
Thank you for your kind words 🙂

[duongf7a]

Thank you so much Mohamed Arsha. You do exactly that I need to

[duongf7a]

Thank you  jeremy tammik, I will take all of that and spend time to read it.

Actually, I've already read so many your articles and I found the Project method, but I still get stuck when I try to fix my error.

So I think my big problem here is I'm not familiar about the computional geometry algorithms such as finding the relative position of the line and point and apply to Revit API. Can you give me some advice. Thank you so much

[jeremy_tammik]

Sure. The Revit API provides a method to project a point onto a line, Line.Project:

• https://www.revitapidocs.com/2024/b87fc3e4-ea25-2a75-5b5a-53065b099d2a.htm

However, you can also easily implement it yourself:

• https://duckduckgo.com/?q=project+point+onto+line+.net+3d