创造3 d文本,将它封装在一个管(Cylind

// FYI - the following are as held as member variables
//        List> pipeProperties;
//        private Point3d position;
//        private Point3d centerOfPipe;
//        private double extrudeHeight;
//        private double outsideDiameter;
//        private double wallThickness;
//        private double pipeLength;
//        private Vector3d pipeVector;
private void CreateEnt(Entity ent)
{
        // Scale the text height...
        Extents3d geometricExtents = ent.GeometricExtents;
        Point3d point3d = new Point3d();
        double mHeight = this.m_height;
        Vector3d vectorTo = point3d.GetVectorTo(geometricExtents.MaxPoint);
        double y = mHeight / vectorTo.Y;
        ent.TransformBy(Matrix3d.Scaling(y, point3d));
        using (Transaction tr = this.m_db.TransactionManager.StartTransaction())
        {
                try
                {
                        BlockTableRecord btr = tr.GetObject(this.m_db.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord;
                        ent.SetDatabaseDefaults();
                        // Extrude this region just beyond the thickness of the pipe... 
                        var pSolid = new Solid3d { RecordHistory = true };
                        pSolid.Extrude(ent as Region, extrudeHeight, 0.0);
                        // Move this region to the center point of the pipe, and move it down so it is vertically center justified...
                        var centerJustPoint = new Point3d(centerOfPipe.X, centerOfPipe.Y, centerOfPipe.Z - (extrudeHeight / 4.0));
                        pSolid.TransformBy(Matrix3d.Displacement(centerJustPoint - Point3d.Origin));
                        // Now the text region is by default oriented so that the text is laying down flat. Hard code transform to be "vertical" so the 
                        // text region is up. 
                        // ** how do I figure out the proper orientation of the text region to match the orientation of the pipe...??
                        Matrix3d matrix = Matrix3d.Rotation(Math.PI / 2, Vector3d.XAxis, centerJustPoint);
                        pSolid.TransformBy(matrix);
                                                 
                        // Add this solid to the model...
                        btr.AppendEntity(pSolid);
                        tr.AddNewlyCreatedDBObject(pSolid, true);                    
                        // Create the cylinder that will be subtracted from the text regoin, and move it to the center point of the pipe..
                        var cyl = new Solid3d { RecordHistory = true };
                        var radius = (outsideDiameter / 2.0); 
                        cyl.CreateFrustum(pipeLength, radius, radius, radius);
                        cyl.TransformBy(Matrix3d.Displacement(centerOfPipe - Point3d.Origin));
                        // Now this cylinder and text region is simply using the default orientation. Manually hard code to orientate it, just like above, 
                        // so that it matches the text orientation.. 
                        // ** obviouslly this is wrong and won't handle, for example, vertical pipes.. how do I align this and the text to the orientation 
                        //    of the pipe. 
                        
                        Matrix3d matrix2 = Matrix3d.Rotation(Math.PI / 2, Vector3d.YAxis, centerOfPipe);
                        cyl.TransformBy(matrix2);
                        // Lots of test code here to try to orientate / align the cylinder and text to the pipe... see previous post that describes the approaches
                        // that I attempted, but couldn't figure out...
                        
                        btr.AppendEntity(cyl);
                        tr.AddNewlyCreatedDBObject(cyl, true);
                        // Subtract the cylinder from the text region.. 
                        pSolid.BooleanOperation(BooleanOperationType.BoolSubtract, cyl);
                }
                catch
                {
                        this.m_isValid = false;
                }
                finally
                {
                        tr.Commit();
                }
        }
}