Edit 3D Solids

Once you have created a solid, you can create more complex shapes by combining or subtracting solids. You can join solids, subtract solids from each other, or find the common volume (overlapping portion) of solids. Use the BooleanOperation method to perform these combinations. The CheckInterference method allows you to determine if two solids overlap.

Solids are further modified by obtaining the 2D cross section of a solid or slicing a solid into two pieces. Use the GetSection method to find cross sections of solids, and the Slice method for slicing a solid into two pieces.

Find the interference between two solids

This example creates a box and cylinder. It then finds the interference between the two solids and creates a new solid from that interference. For ease of viewing, the box is colored white, the cylinder is colored cyan, and the interference solid is colored red.

VB.NET

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

<CommandMethod("FindInterferenceBetweenSolids")> _

Public Sub FindInterferenceBetweenSolids()

  '' Get the current document and database, and start a transaction

  Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument

  Dim acCurDb As Database = acDoc.Database

  Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

      '' Open the Block table for read

      Dim acBlkTbl As BlockTable

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, _

                                   OpenMode.ForRead)

      '' Open the Block table record Model space for write

      Dim acBlkTblRec As BlockTableRecord

      acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _

                                      OpenMode.ForWrite)

      '' Create a 3D solid box

      Dim acSol3DBox As Solid3d = New Solid3d()

      acSol3DBox.CreateBox(5, 7, 10)

      acSol3DBox.ColorIndex = 7

      '' Position the center of the 3D solid at (5,5,0)

      acSol3DBox.TransformBy(Matrix3d.Displacement(New Point3d(5, 5, 0) - _

                                                   Point3d.Origin))

      '' Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DBox)

      acTrans.AddNewlyCreatedDBObject(acSol3DBox, True)

      '' Create a 3D solid cylinder

      '' 3D solids are created at (0,0,0) so there is no need to move it

      Dim acSol3DCyl As Solid3d = New Solid3d()

      acSol3DCyl.CreateFrustum(20, 5, 5, 5)

      acSol3DCyl.ColorIndex = 4

      '' Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DCyl)

      acTrans.AddNewlyCreatedDBObject(acSol3DCyl, True)

      '' Create a 3D solid from the interference of the box and cylinder

      Dim acSol3DCopy As Solid3d = acSol3DCyl.Clone()

      '' Check to see if the 3D solids overlap

      If acSol3DCopy.CheckInterference(acSol3DBox) = True Then

          acSol3DCopy.BooleanOperation(BooleanOperationType.BoolIntersect, _

                                       acSol3DBox.Clone())

          acSol3DCopy.ColorIndex = 1

      End If

      '' Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DCopy)

      acTrans.AddNewlyCreatedDBObject(acSol3DCopy, True)

      '' Save the new objects to the database

      acTrans.Commit()

  End Using

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.Geometry;

[CommandMethod("FindInterferenceBetweenSolids")]

public static void FindInterferenceBetweenSolids()

  // Get the current document and database, and start a transaction

  Document acDoc = Application.DocumentManager.MdiActiveDocument;

  Database acCurDb = acDoc.Database;

  using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())

      // Open the Block table record for read

      BlockTable acBlkTbl;

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,

                                   OpenMode.ForRead) as BlockTable;

      // Open the Block table record Model space for write

      BlockTableRecord acBlkTblRec;

      acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],

                                      OpenMode.ForWrite) as BlockTableRecord;

      // Create a 3D solid box

      Solid3d acSol3DBox = new Solid3d();

      acSol3DBox.CreateBox(5, 7, 10);

      acSol3DBox.ColorIndex = 7;

      // Position the center of the 3D solid at (5,5,0)

      acSol3DBox.TransformBy(Matrix3d.Displacement(new Point3d(5, 5, 0) -

                                                   Point3d.Origin));

      // Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DBox);

      acTrans.AddNewlyCreatedDBObject(acSol3DBox, true);

      // Create a 3D solid cylinder

      // 3D solids are created at (0,0,0) so there is no need to move it

      Solid3d acSol3DCyl = new Solid3d();

      acSol3DCyl.CreateFrustum(20, 5, 5, 5);

      acSol3DCyl.ColorIndex = 4;

      // Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DCyl);

      acTrans.AddNewlyCreatedDBObject(acSol3DCyl, true);

      // Create a 3D solid from the interference of the box and cylinder

      Solid3d acSol3DCopy = acSol3DCyl.Clone() as Solid3d;

      // Check to see if the 3D solids overlap

      if (acSol3DCopy.CheckInterference(acSol3DBox) == true)

          acSol3DCopy.BooleanOperation(BooleanOperationType.BoolIntersect,

                                       acSol3DBox.Clone() as Solid3d);

          acSol3DCopy.ColorIndex = 1;

      // Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DCopy);

      acTrans.AddNewlyCreatedDBObject(acSol3DCopy, true);

      // Save the new objects to the database

      acTrans.Commit();

VBA/ActiveX Code Reference

Slice a solid into two solids

This example creates a box in model space. It then slices the box based on a plane defined by three points. The slice is returned as a 3DSolid.

VB.NET

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

<CommandMethod("SliceABox")> _

Public Sub SliceABox()

  '' Get the current document and database, and start a transaction

  Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument

  Dim acCurDb As Database = acDoc.Database

  Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

      '' Open the Block table for read

      Dim acBlkTbl As BlockTable

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, _

                                   OpenMode.ForRead)

      '' Open the Block table record Model space for write

      Dim acBlkTblRec As BlockTableRecord

      acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _

                                      OpenMode.ForWrite)

      '' Create a 3D solid box

      Dim acSol3D As Solid3d = New Solid3d()

      acSol3D.CreateBox(5, 7, 10)

      acSol3D.ColorIndex = 7

      '' Position the center of the 3D solid at (5,5,0)

      acSol3D.TransformBy(Matrix3d.Displacement(New Point3d(5, 5, 0) - _

                                                Point3d.Origin))

      '' Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3D)

      acTrans.AddNewlyCreatedDBObject(acSol3D, True)

      '' Define the mirror plane

      Dim acPlane As Plane = New Plane(New Point3d(1.5, 7.5, 0), _

                             New Point3d(1.5, 7.5, 10), _

                             New Point3d(8.5, 2.5, 10))

      Dim acSol3DSlice As Solid3d = acSol3D.Slice(acPlane, True)

      acSol3DSlice.ColorIndex = 1

      '' Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DSlice)

      acTrans.AddNewlyCreatedDBObject(acSol3DSlice, True)

      '' Save the new objects to the database

      acTrans.Commit()

  End Using

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.Geometry;

[CommandMethod("SliceABox")]

public static void SliceABox()

  // Get the current document and database, and start a transaction

  Document acDoc = Application.DocumentManager.MdiActiveDocument;

  Database acCurDb = acDoc.Database;

  using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())

      // Open the Block table record for read

      BlockTable acBlkTbl;

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,

                                   OpenMode.ForRead) as BlockTable;

      // Open the Block table record Model space for write

      BlockTableRecord acBlkTblRec;

      acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],

                                      OpenMode.ForWrite) as BlockTableRecord;

      // Create a 3D solid box

      Solid3d acSol3D = new Solid3d();

      acSol3D.CreateBox(5, 7, 10);

      acSol3D.ColorIndex = 7;

      // Position the center of the 3D solid at (5,5,0)

      acSol3D.TransformBy(Matrix3d.Displacement(new Point3d(5, 5, 0) -

                                                Point3d.Origin));

      // Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3D);

      acTrans.AddNewlyCreatedDBObject(acSol3D, true);

      // Define the mirror plane

      Plane acPlane = new Plane(new Point3d(1.5, 7.5, 0),

                                new Point3d(1.5, 7.5, 10),

                                new Point3d(8.5, 2.5, 10));

      Solid3d acSol3DSlice = acSol3D.Slice(acPlane, true);

      acSol3DSlice.ColorIndex = 1;

      // Add the new object to the block table record and the transaction

      acBlkTblRec.AppendEntity(acSol3DSlice);

      acTrans.AddNewlyCreatedDBObject(acSol3DSlice, true);

      // Save the new objects to the database

      acTrans.Commit();

VBA/ActiveX Code Reference