Topic: Clash detect

[jura]

Hi all,

I've made this clash detection for 3D solids. Basicly it runs through all solids one by one and creates 3D solids of all solids that collide with others. Here's the thing i want to extend the function with. Because (as many others i asume) we draw a lot with predefined blocks, i need to explode all blocks (which are made from 3D solids as well) for the function to run properly. Can this be avoided? I mean can i check for interfering 3D solids within blocks.

Grz, Jura

[Bryco]

No. You have to check each block for the existance of solids then check each blockreference against the rest of modelspace.
(Of course you can check for clashes within the block itself.)
An easier way, though messy, is to exploded the blockrefs (this leaves the blockrefs intact) add these to an array and delete the ones that don't clash.

[jura]

explode the blockrefs (this leaves the blockrefs intact) add these to an array and delete the ones that don't clash.

Could you explain.

How can i explode the blockrefs and leave the blockrefs intact? What is a blockref? Is it the blocks itself?

[David Hall]

Block is the definition, BlockRef is the instance of the block inserted in the dwg

[Bryco]

Like CmdrDuh says, a block is like a list of the objects and their positions relative to zero.
Blocks and blockreferences are quite different and you need to grasp the difference to write successful code.
Try a small sub where you use explode and look at the results.

[jura]

Will do.

My guess: I'll be back on this one.

Thx for the tip guys.

[jura]

After spending some more time on this it feels 'good enough' to share the product with you guys.

See attachment for code + results window.

Here is the code. I fooled around a little with my SSets and Arrays. To me it feels like there must be an easier way to handle this. Some functions however would not accept Arrays and others not Ssets.

Code: [Select]

'#####################################
'# ClashDetect creates 3D solids from
'# selected 3D solids where they
'# interfere with eachother
'# Sub by J.v.d.Staaij
'# V1.0
'#####################################
Sub ClashDetect()
    'original
    Dim originalItems As AcadSelectionSet
    'copy
    Dim copyItem As AcadEntity
    Dim CopiedItemsSSet As AcadSelectionSet
    'explode
    Dim TempEntity As AcadEntity
    Dim TempItem As Variant
    Dim TempArray(0 To 0) As AcadBlockReference
    Dim Counter As Integer
    Dim TempSubEntity As Acad3DSolid
    'clas detect
    Dim ClashSolid As Acad3DSolid
    Dim newLayer, oldLayer
    Dim ChecksExecuted As Long
    Dim FoundClash As Long
    Dim counterNotChecked As Long
    Dim SolidCreationErrorCount As Long
    'pre check
    Dim obj1 As AcadEntity
    Dim obj2 As AcadEntity
    Dim pmin As Variant
    Dim pmax As Variant
    Dim qmin As Variant
    Dim qmax As Variant
    Dim Clash As Integer
   
   
    'Let user select items
    Set originalItems = ThisDrawing.SelectionSets.Add("block")
    originalItems.SelectOnScreen
    'Create templayer
    Set tempLayer = ThisDrawing.Layers.Add("TEMPLAYER")
    'Jumpout when nothing selected
    If originalItems.Count = 0 Then GoTo Einde
    'define dynamic copyarray
    ReDim copyArray(0 To originalItems.Count - 1) As AcadEntity
    'copy each item in original selection
    For i = 0 To originalItems.Count - 1
        Set copyItem = originalItems(i).Copy()
        copyItem.Layer = "TEMPLAYER"
        Set copyArray(i) = copyItem
    Next
    'create copy selectionset
    Set CopiedItemsSSet = ThisDrawing.SelectionSets.Add("ArrayName")
    'store copyarray in selectionset
    CopiedItemsSSet.AddItems copyArray
   
    'Explode blockrefs (and re-explode if necesary)
ExplodeAgain:
    Counter = 0
    For Each TempEntity In CopiedItemsSSet
            If TypeOf TempEntity Is AcadBlockReference Then
                    Set TempArray(0) = TempEntity
                    CopiedItemsSSet.RemoveItems TempArray
                    TempItem = TempEntity.Explode
                    TempEntity.Delete
                    CopiedItemsSSet.AddItems (TempItem)
                    Counter = Counter + 1
            End If
        Next
    If Counter <> 0 Then GoTo ExplodeAgain
    'store currenty layer
    Set oldLayer = ThisDrawing.ActiveLayer
    'create layer for clashing items
    Set newLayer = ThisDrawing.Layers.Add("DetectedClash")
    ThisDrawing.ActiveLayer = newLayer
    ThisDrawing.ActiveLayer.color = 6
    'Set results counters
    ChecksExecuted = 0
    FoundClash = 0
    counterNotChecked = 0
   
    For i = 0 To CopiedItemsSSet.Count - 1
        'Check if item is 3D Solid
        If Not (CopiedItemsSSet(i).ObjectName = "AcDb3dSolid") Then
        counterNotChecked = counterNotChecked + 1
        GoTo SkipCheckObject
        End If
        ' start checking
        For j = i + 1 To CopiedItemsSSet.Count - 1
            If Not (CopiedItemsSSet(j).ObjectName = "AcDb3dSolid") Then GoTo SkipCheckAgainst 'Check if against-item is 3D Solid
                If Not (CopiedItemsSSet(i) Is CopiedItemsSSet(j)) Then 'Don't do self check
                    'Do pre check (easier for acad to compare bounding boxes (10-20x faster))
                    CopiedItemsSSet(i).GetBoundingBox pmin, pmax
                    CopiedItemsSSet(j).GetBoundingBox qmin, qmax
                    Clash = 0
                    For k = 0 To 2
                        limiet = (pmax(k) - pmin(k) + qmax(k) - qmin(k))
                        afstand = Abs(pmax(k) + pmin(k) - qmax(k) - qmin(k))
                        If afstand < limiet Then
                            Clash = Clash + 1
                        End If
                    Next k
                    If Clash = 3 Then ' Precheck is true
                        On Error GoTo ErrorSolidCreate 'Take care of Modeling Operation Errors
                        Set ClashSolid = CopiedItemsSSet(i).CheckInterference(CopiedItemsSSet(j), True)
                        On Error GoTo ErrorTrap
                        ' set found clash to DetectedClash layer
                        If Not (ClashSolid Is Nothing) Then
                            ClashSolid.Layer = "DetectedClash"
                            FoundClash = FoundClash + 1
                        End If 'Not (ClashSolid Is Nothing) Then
                        ChecksExecuted = ChecksExecuted + 1
                    End If 'If Clash = 3 Then
                Else
            End If 'If Not (CopiedItemsSSet(i) Is CopiedItemsSSet(j)) Then 'Don't do self check
SkipCheckAgainst:
        Next
SkipCheckObject:
    Next
    'result window
    ClashDetectResults.Results.Caption = "" & ChecksExecuted & vbCrLf & _
                                            FoundClash & vbCrLf & _
                                            counterNotChecked & vbCrLf & _
                                            SolidCreationErrorCount & ""
   
    ClashDetectResults.Show
    'Restore original layer
    ThisDrawing.ActiveLayer = oldLayer
    'delete templayer
    'ThisDrawing.Layers.Delete (TO DO)
   
    'Error trapping
ErrorTrap:
    CopiedItemsSSet.Erase
    CopiedItemsSSet.Delete
   
Einde:
    originalItems.Delete
    Exit Sub
   
ErrorSolidCreate:
    SolidCreationErrorCount = SolidCreationErrorCount + 1
    Resume Next
   
End Sub