Isolated strange behavior when using DriveConstraintSettings from .net

[Anonymous]

Hello,

I have managed to isolate unexpected, to me, bahavior for DriveConstraintSettings.

If I use drive the constraint detecting contact everything is fine the first time. If I change the position of assemblycomponentoccurences and do the same again it stops at the same position as the previous run.

I suspect that this is due to internal caching of proxies or something.

See attached code and dataset to reproduce.

Please post suggestions and ideas for how to resolve this.

I installed this but to no use. http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=17804829&linkID=9242019

using System;
using System.Management.Instrumentation;
using System.Runtime.InteropServices;
using Inventor;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace SimulationInventorHandlerTest.Utilities.Assembly
{
    [TestClass]
    public class DriveConstraintTest
    {
        [TestMethod]
        public void ProbeTest()
        {
            Application inventorAppliaction = GetInventorAppliaction();
            AssemblyDocument assemblyDocument = GetActiveAssemblyDocument(inventorAppliaction);

            MateConstraint mateConstraintX = GetMateConstraintByName(assemblyDocument, "Axis X");
            Inventor.MateConstraint mateConstraintZ = GetMateConstraintByName(assemblyDocument, "Axis Z");

            assemblyDocument.ModelingSettings.InteractiveContactAnalysis = Inventor.InteractiveContactAnalysisEnum.kAllComponentsInteractiveContact;
            assemblyDocument.ModelingSettings.InteractiveContactSurfaces = Inventor.InteractiveContactSurfacesEnum.kAllSurfacesInteractiveContact;

            mateConstraintX.Offset.Expression = "0 mm";
            mateConstraintZ.Offset.Expression = "20 mm";
            assemblyDocument.Update();
            Drive(0, 10, 0.1, mateConstraintX);
            double stopPosition = mateConstraintX.Offset.ModelValue;

            mateConstraintX.Offset.Expression = "0 mm";
            mateConstraintZ.Offset.Expression = "0 mm";
            assemblyDocument.Update();
            Drive(0, 10, 0.1, mateConstraintX);

            if(Math.Abs(stopPosition - mateConstraintX.Offset.ModelValue) < 0.0001) throw new Exception("Stopped at same position as first run!");

        }

        private void Drive(double startValue, double endValue, double incrementSize, MateConstraint mateConstraint )
        {
            mateConstraint.DriveConstraintSettings.CollisionDetection = true;
            mateConstraint.DriveConstraintSettings.SetIncrement(Inventor.ConstraintIncrementTypeEnum.kIncrementAsAmountOfValue, incrementSize.ToString());

            mateConstraint.DriveConstraintSettings.StartValue = startValue.ToString();

            mateConstraint.DriveConstraintSettings.EndValue = endValue.ToString();
            mateConstraint.DriveConstraintSettings.GoToStart();
            mateConstraint.DriveConstraintSettings.PlayForward();
        }

        private static MateConstraint GetMateConstraintByName(AssemblyDocument assemblyDocument, string constraintName)
        {
            MateConstraint mateConstraint;
            Inventor.AssemblyComponentDefinition assemblyComponentDefinition = assemblyDocument.ComponentDefinition;
            if (!(assemblyComponentDefinition.Constraints[constraintName] is Inventor.MateConstraint))
                throw new InstanceNotFoundException("Not a MateConstraint");


            mateConstraint = assemblyComponentDefinition.Constraints[constraintName] as Inventor.MateConstraint;
            if (mateConstraint == null) throw new InstanceNotFoundException("No constraint");
            return mateConstraint;
        }

        private static AssemblyDocument GetActiveAssemblyDocument(Application inventorAppliaction)
        {
            AssemblyDocument assemblyDocument;
            if (!(inventorAppliaction.ActiveDocument is Inventor.AssemblyDocument))
            {
                throw new InstanceNotFoundException("No active asseblydocument");
            }
            assemblyDocument = inventorAppliaction.ActiveDocument as Inventor.AssemblyDocument;
            return assemblyDocument;
        }

        private static Application GetInventorAppliaction()
        {
            Application inventorAppliaction;
            inventorAppliaction = Marshal.GetActiveObject("Inventor.Application") as Inventor.Application;

            return inventorAppliaction;
        }
    }
}

[Anonymous]

Corresponding VBA code

Public Sub StrangeBehavior()
    Dim assyDoc As AssemblyDocument
    Set assyDoc = ThisApplication.ActiveDocument
    
    assyDoc.ModelingSettings.InteractiveContactAnalysis = kAllComponentsInteractiveContact
    assyDoc.ModelingSettings.InteractiveContactSurfaces = kAllSurfacesInteractiveContact
    Dim xConstraint As MateConstraint
    Set xConstraint = assyDoc.ComponentDefinition.Constraints.Item("Axis X")

    Call xConstraint.DriveConstraintSettings.SetIncrement(kIncrementAsAmountOfValue, "0,1")
    Dim zConstraint As MateConstraint
    Set zConstraint = assyDoc.ComponentDefinition.Constraints.Item("Axis Z")
    xConstraint.Offset.Value = 0
    zConstraint.Offset.Value = 0
    assyDoc.Update
    With xConstraint.DriveConstraintSettings
        .CollisionDetection = True
        .StartValue = 0
        .EndValue = 20
        .GoToStart
        .PlayForward
    End With
    firstposition = xConstraint.Offset.Value
    xConstraint.Offset.Value = 0
    zConstraint.Offset.Value = 2
    assyDoc.Update
    With xConstraint.DriveConstraintSettings
        .CollisionDetection = True
        .StartValue = 0
        .EndValue = 20
        .GoToStart
        .PlayForward
    End With
    If (firstposition - xConstraint.Offset.Value) ^ 2 < 0.001 Then
        MsgBox ("Same position as first time, this is not corrrect!")
    End If
    
End Sub

[Anonymous]

How can I call  ?Clear@RDxCollisionDetector@@QEAAXXZ in rd.dll via pInvoke?

As described in this blog: http://through-the-interface.typepad.com/through_the_interface/2011/05/calling-unexposed-objectarx-m...

It seems the collision detector is not cleared between runs when drive constraint is invoked from .net.

An other option would be to make an API call that triggers a call to CollisionDetector.Clear, I have not found óne yet.

[Anonymous]

I think I found a really ugly solution to the problem.

I start a new process just to drive the constraint, the code is so ugly so atm so I am not posting. If anyone wants it I can post after cleaning it a bit.

[Anonymous]

Here is the pseudo code, its really ugly. i guess it shoul be a recursive call but I kept it this way. The key to repeated animation is the finally block. The code in the catch blocks handles the quite common case when Inventor fails to detect contact. I think you will be able to figure out the axismotion class.

        private void DriveConstraintInNegativeDirection(AssemblyConstraint assemblyConstraint, AxisMotion axisMotion)
        {
            DriveConstraintSettings driveConstraintSettings = assemblyConstraint.DriveConstraintSettings;
            try
            {
                if (Math.Abs(axisMotion.CurrentUnitPosition - axisMotion.FromExpression.UnitValue) > double.Epsilon)
                    throw new InvalidOperationException("Currentpostition got to be fromposition!");
                driveConstraintSettings.StartValue = axisMotion.ToExpression.ExpressionString;
                driveConstraintSettings.PlayReverse();
                SetIncrement(AxisMotion, AxisMotion.Axis.AxisSetting.Resolution);
                while (AxisMotion.Axis.IsInterference)
                {
                    driveConstraintSettings.StepForward();
                }
            }
            catch (Exception)
            {
                try
                {
                    while (AxisMotion.Axis.IsInterference)
                    {
                        driveConstraintSettings.StepForward();
                    }
                    SetIncrement(AxisMotion, 0.01);
                    driveConstraintSettings.PlayReverse();
                    SetIncrement(AxisMotion, AxisMotion.Axis.AxisSetting.Resolution);
                    while (AxisMotion.Axis.IsInterference)
                    {
                        driveConstraintSettings.StepForward();
                    }
                }
                catch (Exception)
                {
                    try
                    {
                        while (AxisMotion.Axis.IsInterference)
                        {
                            driveConstraintSettings.StepForward();
                        }
                        SetIncrement(AxisMotion, AxisMotion.Axis.AxisSetting.Resolution);
                        driveConstraintSettings.PlayReverse();
                        while (AxisMotion.Axis.IsInterference)
                        {
                            driveConstraintSettings.StepForward();
                        }
                    }
                    catch (Exception)
                    {
                        while (AxisMotion.Axis.IsInterference)
                        {
                            driveConstraintSettings.StepForward();
                        }
                        //throw;
                    }
                }
            }
            finally
            {
                Marshal.FinalReleaseComObject(driveConstraintSettings);
            }
        }