topic Re: Align Entity 3D in .NET Forum

Align Entity 3D

Civil3DReminders_com — Tue, 24 Mar 2020 06:35:01 GMT

I'm attempting to align an entity (BlockReference or 3D Polyline) in 3D. I'm not having much luck finding sample code that works.

I've tried this post: https://adndevblog.typepad.com/autocad/2012/04/finding-transformation-matrix-for-aligning-two-entities.html#tpe-action-posted-6a0167607c2431970b0240a4f521fc200d

It's been linked to in other posts in this forum, but it doesn't appear to work correctly as shown in this screencast: https://autode.sk/2y4D51k

Here is the drawing information to recreate the linework, I've also attached the drawing.

3DPoly 652492.7740,367502.1323,2867.9053 652534.3375,367499.4847,2862.0912

point 652492.7740,367502.1323,2867.9053
point 652534.7389,367499.4590,2867.5313

Below is the code I've been testing with, with the trans4 corrected for what I think is a typo.

If I run the code multiple times it converges to a more correct solution, but I don't think that should be required.

<CommandMethod("S-Test")> Sub Test() Try '' Put your command code here 'Using tr As Transaction = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.TransactionManager.StartTransaction ' Dim pipe3dAlign As New Pipe3DAlign ' pipe3dAlign.RunCommandTest(tr) ' tr.Commit() 'End Using Dim activeDoc As Document = Application.DocumentManager.MdiActiveDocument Dim db As Database = activeDoc.Database Dim ed As Editor = activeDoc.Editor Dim per As PromptEntityResult = ed.GetEntity(New PromptEntityOptions("Select an entity : ")) If (per.Status <> PromptStatus.OK) Then Return End If Dim oid As ObjectId = per.ObjectId Dim ppr1 As PromptPointResult = ed.GetPoint(New PromptPointOptions("Select src point 1")) If (ppr1.Status <> PromptStatus.OK) Then Return End If Dim sp1 As Point3d = ppr1.Value Dim ppr2 As PromptPointResult = ed.GetPoint(New PromptPointOptions("Select src point 2")) If (ppr2.Status <> PromptStatus.OK) Then Return End If Dim ep1 As Point3d = ppr2.Value Dim ppr3 As PromptPointResult = ed.GetPoint(New PromptPointOptions("Select dest point 1")) If (ppr3.Status <> PromptStatus.OK) Then Return End If Dim sp2 As Point3d = ppr3.Value Dim ppr4 As PromptPointResult = ed.GetPoint(New PromptPointOptions("Select dest point 2")) If (ppr4.Status <> PromptStatus.OK) Then Return End If Dim ep2 As Point3d = ppr4.Value Dim resMat As Matrix3d = Matrix3d.Identity Dim trans1 As Matrix3d = Matrix3d.Displacement(sp2 - sp1) sp1 = sp1.TransformBy(trans1) ep1 = ep1.TransformBy(trans1) resMat = resMat.PreMultiplyBy(trans1) ' // Rotation about Z axis Dim dir1 As Vector3d = ep1 - sp1 Dim dir2 As Vector3d = ep2 - sp2 Dim xy As Plane = New Plane(Point3d.Origin, Vector3d.ZAxis) Dim trans2 As Matrix3d = Matrix3d.Rotation(dir2.AngleOnPlane(xy) - dir1.AngleOnPlane(xy), Vector3d.ZAxis, sp1) sp1 = sp1.TransformBy(trans2) ep1 = ep1.TransformBy(trans2) resMat = resMat.PreMultiplyBy(trans2) ' // Rotation about X axis dir1 = ep1 - sp1 dir2 = ep2 - sp2 Dim yz As Plane = New Plane(Point3d.Origin, Vector3d.XAxis) Dim trans3 As Matrix3d = Matrix3d.Rotation(dir2.AngleOnPlane(yz) - dir1.AngleOnPlane(yz), Vector3d.XAxis, sp1) sp1 = sp1.TransformBy(trans3) ep1 = ep1.TransformBy(trans3) resMat = resMat.PreMultiplyBy(trans3) '// Rotation about Y axis dir1 = ep1 - sp1 dir2 = ep2 - sp2 Dim xz As Plane = New Plane(Point3d.Origin, Vector3d.YAxis) Dim trans4 As Matrix3d = Matrix3d.Rotation(dir2.AngleOnPlane(xz) - dir1.AngleOnPlane(xz), Vector3d.YAxis, sp1) sp1 = sp1.TransformBy(trans4) ep1 = ep1.TransformBy(trans4) resMat = resMat.PreMultiplyBy(trans4) '// Scaling dir1 = ep1 - sp1 dir2 = ep2 - sp2 Dim trans5 As Matrix3d = Matrix3d.Scaling(dir2.Length / dir1.Length, sp1) sp1 = sp1.TransformBy(trans5) ep1 = ep1.TransformBy(trans5) resMat = resMat.PreMultiplyBy(trans5) Using tr As Transaction = db.TransactionManager.StartTransaction() Dim ent As Entity = tr.GetObject(oid, OpenMode.ForWrite) ent.TransformBy(resMat) tr.Commit() End Using Catch EX As System.Exception MsgBox("Error: " & EX.Message) End Try End Sub

Re: Align Entity 3D

_gile — Wed, 25 Mar 2020 07:12:34 GMT

Hi,

If you want to align an entity in 3D, you need to specify 3 (non colinear) source points and 3 (non colinear) destination points to be able to define the source plane and destination plane.

Here's an example:

[CommandMethod("TEST")] public static void Test() { var doc = AcAp.DocumentManager.MdiActiveDocument; var db = doc.Database; var ed = doc.Editor; var per = ed.GetEntity("\nSelect entity: "); if (per.Status != PromptStatus.OK) return; var ppo = new PromptPointOptions("\nSpecify the first source point: "); var ppr = ed.GetPoint(ppo); if (ppr.Status != PromptStatus.OK) return; var srcPt1 = ppr.Value; ppo.Message = "\nSpecify the second source point: "; ppr = ed.GetPoint(ppo); if (ppr.Status != PromptStatus.OK) return; var srcPt2 = ppr.Value; ppo.Message = "\nSpecify the third source point: "; ppr = ed.GetPoint(ppo); if (ppr.Status != PromptStatus.OK) return; var srcPt3 = ppr.Value; ppo.UseBasePoint = true; ppo.Message = "\nSpecify the first destinaton point: "; ppo.BasePoint = srcPt1; ppr = ed.GetPoint(ppo); if (ppr.Status != PromptStatus.OK) return; var destPt1 = ppr.Value; ppo.Message = "\nSpecify the second destinaton point: "; ppo.BasePoint = srcPt2; ppr = ed.GetPoint(ppo); if (ppr.Status != PromptStatus.OK) return; var destPt2 = ppr.Value; ppo.Message = "\nSpecify the first destinaton point: "; ppo.BasePoint = srcPt3; ppr = ed.GetPoint(ppo); if (ppr.Status != PromptStatus.OK) return; var destPt3 = ppr.Value; var ucs = ed.CurrentUserCoordinateSystem; srcPt1 = srcPt1.TransformBy(ucs); srcPt2 = srcPt2.TransformBy(ucs); srcPt3 = srcPt3.TransformBy(ucs); destPt1 = destPt1.TransformBy(ucs); destPt2 = destPt2.TransformBy(ucs); destPt3 = destPt3.TransformBy(ucs); var srcCs = CreateCoordinateSystem(srcPt1, srcPt2, srcPt3); var destCs = CreateCoordinateSystem(destPt1, destPt2, destPt3); var xform = Matrix3d.AlignCoordinateSystem( srcPt1, srcCs.Xaxis, srcCs.Yaxis, srcCs.Zaxis, destPt1, destCs.Xaxis, destCs.Yaxis, destCs.Zaxis) * Matrix3d.Scaling(destPt1.DistanceTo(destPt2) / srcPt1.DistanceTo(srcPt2), srcPt1); using (var tr = db.TransactionManager.StartTransaction()) { var ent = (Entity)tr.GetObject(per.ObjectId, OpenMode.ForWrite); ent.TransformBy(xform); tr.Commit(); } } private static CoordinateSystem3d CreateCoordinateSystem(Point3d pt1, Point3d pt2, Point3d pt3) { var xAxis = pt1.GetVectorTo(pt2).GetNormal(); var vec2 = pt1.GetVectorTo(pt3); if (xAxis.IsParallelTo(vec2)) throw new Autodesk.AutoCAD.Runtime.Exception(ErrorStatus.InvalidAxis); var zAxis = xAxis.CrossProduct(vec2).GetNormal(); var yAxis = zAxis.CrossProduct(xAxis).GetNormal(); return new CoordinateSystem3d(pt1, xAxis, yAxis); }

Re: Align Entity 3D

essam-salah — Sun, 16 Jul 2023 11:27:29 GMT

hi @_gile

@_gile wrote:

... * Matrix3d.Scaling(destPt1.DistanceTo(destPt2) / srcPt1.DistanceTo(srcPt2), srcPt1);

why we have to scale the source object?

i have two identical source and destination objects and tried the code without the scaling and it doesn't work, i don't know why, in my case i have <srcPt1,srcPt2> distance equals to <destPt1,destPt2> distance, also <srcPt2,srcPt3> distance equals to <destPt2,destPt3> distance, im confused right now.

Re: Align Entity 3D

_gile — Sun, 16 Jul 2023 14:28:06 GMT

@essam-salah a écrit :

why we have to scale the source object?

i have two identical source and destination objects and tried the code without the scaling and it doesn't work,

Scaling the source object is not mandatory.

it does work without scaling if you repalce:

var xform = Matrix3d.AlignCoordinateSystem( srcPt1, srcCs.Xaxis, srcCs.Yaxis, srcCs.Zaxis, destPt1, destCs.Xaxis, destCs.Yaxis, destCs.Zaxis) * Matrix3d.Scaling(destPt1.DistanceTo(destPt2) / srcPt1.DistanceTo(srcPt2), srcPt1);

with:

var xform = Matrix3d.AlignCoordinateSystem( srcPt1, srcCs.Xaxis, srcCs.Yaxis, srcCs.Zaxis, destPt1, destCs.Xaxis, destCs.Yaxis, destCs.Zaxis);