topic Re : Preview Window in AutoCAD using .NET API in .NET Forum

Preview Window in AutoCAD using .NET API

Anonymous — Mon, 14 Sep 2015 18:29:10 GMT

Hi everyone, I want to build the application such like that it shows preview in the GUI (User Interface) before it draw anything in the AutoCAD. Note that I want to create 3D objects in AutoCAD and if possible then preview window should be allow user to rotate the 3D objects using mouse in preview window. I hope this much is enough to understand my requirement. Thanks in advance.

Re : Preview Window in AutoCAD using .NET API

FRFR1426 — Tue, 15 Sep 2015 07:16:43 GMT

You can render to a picture box this way:

Manager gsm = doc.GraphicsManager;

using (var view = new View())
{
  var cvport = (short)Application.GetSystemVariable("CVPORT");
  doc.GraphicsManager.SetViewFromViewport(view, cvport);
  view.SetView(new Point3d(0, 0, 1), Point3d.Origin, Vector3d.YAxis, pictureBox.Width, 
    pictureBox.Height);
  var descriptor = new KernelDescriptor();
  descriptor.addRequirement(Autodesk.AutoCAD.UniqueString.Intern("3D Drawing"));
  GraphicsKernel kernel = Manager.AcquireGraphicsKernel(descriptor);
  Device dev = gsm.CreateAutoCADOffScreenDevice(kernel);
  using (dev)
  {
    dev.OnSize(pictureBox.Size);
    dev.DeviceRenderType = RendererType.Default;
    dev.BackgroundColor = Color.White;
    dev.Add(view);
    dev.Update();
    try
    {
      using (Model model = gsm.CreateAutoCADModel(kernel))
      {
        var extents3D = new Extents3d();
        var line = new Line(p1, p2);
        
        [..]
        
        view.Add(line, model);
        extents3D.AddExtents(line.Bounds.Value);
        
        view.ZoomExtents(extents3D.MinPoint, extents3D.MaxPoint);
        view.Zoom(0.9);
      }
      pictureBox.Image = view.GetSnapshot(new Rectangle(0, 0, pictureBox.Width - 1,
        pictureBox.Height - 1));
    finally
    {
      view.EraseAll();
      dev.Erase(view);
      if (null != line)
        line.Dispose();      
    }
  }
}

Re : Preview Window in AutoCAD using .NET API

Anonymous — Wed, 16 Sep 2015 04:38:20 GMT

Thanks for your help...! Just one question will I be able to rotate objects in picture box through Mouse?

Re : Preview Window in AutoCAD using .NET API

FRFR1426 — Wed, 16 Sep 2015 07:58:47 GMT

No this code is for a static preview. To get orbit functionality, you'll need to write a custom control which will handle the mouse movements and call view.Orbit to update the view.

Re : Preview Window in AutoCAD using .NET API

dgorsman — Wed, 16 Sep 2015 16:15:18 GMT

A slightly sideways but less development-intensive option may be to generate a temporary 3D DWF and then pass it to a separate Design Review or Navisworks Freedom session; there might also be the option to embed a Navisworks viewer object. All the navigation tools, none of the labor.

Re : Preview Window in AutoCAD using .NET API

FRFR1426 — Wed, 16 Sep 2015 17:20:20 GMT

http://through-the-interface.typepad.com/through_the_interface/2008/06/autocad-net-ver.html

Re : Preview Window in AutoCAD using .NET API

FRFR1426 — Wed, 16 Sep 2015 18:22:47 GMT

Here is a complete control:

using System;
using System.Drawing;
using System.Windows.Forms;
using Autodesk.AutoCAD;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.GraphicsSystem;
using Application = Autodesk.AutoCAD.ApplicationServices.Application;
using View = Autodesk.AutoCAD.GraphicsSystem.View;

namespace TestCS
{
    public partial class PreviewUserControl : UserControl
    {
        #region Fields

        Device device;

        Extents3d extents;

        Model model;

        Solid3d solid;

        Point start;

        View view;

        #endregion

        #region Constructors

        public PreviewUserControl()
        {
            InitializeComponent();

            SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint, true);
        }

        #endregion

        #region Methods

        void CleanUp()
        {
            if (solid != null)
            {
                solid.Dispose();
                solid = null;
            }

            if (model != null)
            {
                model.Dispose();
                model = null;
            }

            if (view != null)
            {
                // View need to be removed from device
                device?.EraseAll();

                view.Dispose();
                view = null;
            }

            if (device != null)
            {
                device.Dispose();
                device = null;
            }
        }

        protected override void CreateHandle()
        {
            base.CreateHandle();

            if (DesignMode) return;

            Document doc = Application.DocumentManager.MdiActiveDocument;
            Manager gsm = doc.GraphicsManager;

            var descriptor = new KernelDescriptor();
            descriptor.addRequirement(UniqueString.Intern("3D Drawing"));
            GraphicsKernel kernel = Manager.AcquireGraphicsKernel(descriptor);
            device = gsm.CreateAutoCADDevice(kernel, Handle);
            device.OnSize(Size);

            view = new View();
            view.SetView(new Point3d(1, 1, 1), view.Target, view.UpVector, view.FieldWidth, view.FieldHeight);
            device.Add(view);

            model = gsm.CreateAutoCADModel(kernel);
            extents = new Extents3d();

            solid = new Solid3d();
            solid.CreateBox(1, 1, 1);
            solid.ColorIndex = 1;
            view.Add(solid, model);
            if (solid.Bounds != null) extents.AddExtents(solid.Bounds.Value);

            HandleDestroyed += PreviewUserControl_HandleDestroyed;
        }

        protected override void OnMouseDoubleClick(MouseEventArgs e)
        {
            base.OnMouseDoubleClick(e);
            view.ZoomExtents(extents.MinPoint, extents.MaxPoint);
            RefreshView();
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);
            start = e.Location;
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            base.OnMouseMove(e);
            if (e.Button != MouseButtons.Left) return;
            view.Orbit(Math.PI * (start.X - e.X) / Width, Math.PI * (e.Y - start.Y) / Height);
            start = e.Location;
            RefreshView();
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            RefreshView();
        }

        protected override void OnSizeChanged(EventArgs e)
        {
            base.OnSizeChanged(e);
            device?.OnSize(Size);
            RefreshView();
        }

        void PreviewUserControl_HandleDestroyed(object sender, EventArgs e)
        {
            CleanUp();
        }

        void RefreshView()
        {
            if (view == null) return;
            view.Invalidate();
            view.Update();
        }

        #endregion
    }
}

Re : Preview Window in AutoCAD using .NET API

Anonymous — Thu, 17 Sep 2015 05:21:23 GMT

Hi, I am not able to build the Application due to KernelDescriptor. var descriptor = new KernelDescriptor(); 1. May I know which references I have to add for KernelDescriptor? Is this class belonging to AutoCAD APIs or Microsoft(Visual Studio) APIs ? 2. This code is for AutoCAD .NET API not for ObjectARX. Am I Right ?

Re : Preview Window in AutoCAD using .NET API

FRFR1426 — Thu, 17 Sep 2015 06:36:01 GMT

KernelDescriptor is for AutoCAD 2015 and more. Before that, you only need to pass the window handle to the CreateAutoCADDevice method:

device = gsm.CreateAutoCADDevice(Handle);

1. KernelDescriptor is in the Autodesk.AutoCAD.GraphicsSystem namespace (Acdbmgd.dll). It's an AutoCAD API.

2. It's for .NET API, not for ObjectARX (C++) API

Re : Preview Window in AutoCAD using .NET API

Anonymous — Mon, 25 Apr 2016 12:53:20 GMT

Bonjour, Je viens d'utiliser votre exemple (super au passage), et j'aimerai après l'orbite pouvoir revenir à une vue de dessus... sans succès. :(( Cordialement.

Re : Preview Window in AutoCAD using .NET API

FRFR1426 — Tue, 26 Apr 2016 07:43:05 GMT

Pour les vues standards (ortho/isométrique), il faut utiliser la méthode SetView qui permet de repositionner la caméra. Pour une vue de dessus (vue du plan XY), ça donne ça :

view.SetView(view.Target + Vector3d.ZAxis, view.Target, Vector3d.YAxis, view.FieldWidth, view.FieldHeight);

On conserve la cible et les dimensions du champ de vue, on positionne la caméra juste au dessus de la cible et on réaligne le haut de la caméra avec l'axe Y.

Re : Preview Window in AutoCAD using .NET API

Anonymous — Tue, 03 May 2016 06:06:58 GMT

Merci pour votre réponse.

Cordialement.

Patrick.

Re: Re : Preview Window in AutoCAD using .NET API

Anonymous — Sat, 16 Sep 2017 01:52:46 GMT

Do I lack of some namespace or class KernelDescriptor is a new one?

Re: Re : Preview Window in AutoCAD using .NET API

norman.yuan — Sat, 16 Sep 2017 13:27:23 GMT

If you read through the thread carefully, you'd have seen it:

FRFR1426 answered it on 09-16-2015: The name space is Autodesk.AutoCAD.GraphicsSystem (in acdbmgd.dll).

Re: Re : Preview Window in AutoCAD using .NET API

kerry_w_brown — Sat, 16 Sep 2017 22:52:46 GMT

@Anonymous

I think Norman means Post 9 of 14

The dates displayed are expressed in local time and may differ for readers in differing locations.

Regards,

Re: Re : Preview Window in AutoCAD using .NET API

Anonymous — Mon, 21 May 2018 06:47:56 GMT

Hello,
How do you incorporate 'LineWeight' on this?
I wanted to adapt this on our app's preview window, and I wanted to add a feature where an object appears to be highlighted (in a sense that the line weight would appear bolder) on the snapshot.

Re: Re : Preview Window in AutoCAD using .NET API

A_Taha — Sat, 02 Apr 2022 10:08:04 GMT

Thanks for the control, it works great. Is it possible to add zoom-in and zoom-out functionality with the mouse wheel?

Regards,
A. Taha

Re: Re : Preview Window in AutoCAD using .NET API

_gile — Sat, 02 Apr 2022 16:08:38 GMT

Hi,

You can override the OnMouseWheel event handler.

protected override void OnMouseWheel(MouseEventArgs e) { base.OnMouseWheel(e); if (0 < e.Delta) view.Zoom(1.6); else view.Zoom(0.625); RefreshView(); }

Re: Preview Window in AutoCAD using .NET API

veli_vaisanen — Thu, 30 Oct 2025 13:25:33 GMT

Hi,

by the way is it possible to preview hatch entity in this control?

I try one time to do it but there is problem that hatch should be database resident when you can set closed area entity to it.

Br. Veli

Re: Preview Window in AutoCAD using .NET API

ActivistInvestor — Thu, 30 Oct 2025 22:14:11 GMT

With basic entity types, You have to add the entity to the database or add it to the model if the entity is not in a database. Although I am not sure if hatches that are not database-resident can be displayed by just adding them to the model because they may have a dependence on the database.

Beware, that there are issues with solid fill (both hatches and wide polylines). The issue can be solved for wide polyLines by using a DrawableOverrule, but solid-filled hatches are another matter.