This article explains how to import and export geometry from Eyeshot.

Import

Supposing you want to import an OBJ file (all the import methods follow the same scheme) you need the ReadOBJ class. This class gives you full control on all the imported items (entities, blocks, layers, materials, etc.) before adding them to the scene. During file import, you can also control whether to read the file synchronously or asynchronously. Read from stream is also supported through overloaded constructors.

A ReadOBJ class example follows (for synchronous read). The AddToScene() method takes care of adding all the necessary items in the correct order to the scene.

ReadOBJ ro = new ReadOBJ("fileName.obj");
ro.DoWork();

// access/change the loaded items
Entity[] entList = ro.Entities;
Dictionary<string, Material> matList = ro.Materials; 

// add items to the scene
ro.AddToScene(viewportLayout1);

Dim ro As New ReadOBJ("fileName.obj")
ro.DoWork()

' access/change the loaded items
Dim entList As Entity() = ro.Entities
Dim matList As Dictionary(Of String, Material) = ro.Materials

' add items to the scene
ro.AddToScene(viewportLayout1)

A custom ReadOBJ class example follows (asynchronous read).

public class MyReadOBJ : ReadOBJ
{
   public MyReadObj(string fileName) : base(fileName)
   {
   }

   protected override void WorkCompleted(ViewportLayout viewportLayout)
   {
      // access/change the loaded items
      Entity[] entList = Entities;

      // add items to the scene
      AddToScene(viewportLayout1);
   }
}

// custom class usage
MyReadOBJ mro = new MyReadOBJ(fileName);
viewportLayout1.StartWork(mro);

Class MyReadOBJ
   Inherits ReadOBJ

   Public Sub New(fileName As String)
      MyBase.New(fileName)
   End Sub

   Protected Overrides Sub WorkCompleted(viewportLayout As ViewportLayout)
      ' access/change the loaded items
      Dim entList As Entity() = Entities

      ' add items to the scene
      AddToScene(viewportLayout1)
   End Sub
End Class

' custom class usage
Dim mro As MyReadOBJ = New MyReadOBJ(fileName)
viewportLayout1.StartWork(mro)

To avoid deriving a new class from ReadOBJ you can subscribe to the ViewportLayout.WorkCompletedEventHandler and access/change loaded items in the event handler.

public class Form1 : Form
{
   public Form1()
   {
      InitializeComponent();

      viewportLayout1.WorkCompleted += ViewportLayout1OnWorkCompleted;

      ReadOBJ ro = new ReadOBJ("fileName.obj");

      viewportLayout1.StartWork(ro);
   }

   private void ViewportLayout1OnWorkCompleted(object sender, WorkCompletedEventArgs workCompletedEventArgs)
   {
      ReadOBJ ro = (ReadOBJ) workCompletedEventArgs.WorkUnit;

      // access/change the loaded items
      Entity[] entList = ro.Entities;

      // add items to the scene
      ro.AddToScene(viewportLayout1);
   }
}

Public Class Form1
   Inherits Form

   public Sub New()
      InitializeComponent()

      AddHandler viewportLayout1.WorkCompleted, AddressOf ViewportLayout1OnWorkCompleted

      Dim ro As New ReadOBJ("fileName.obj")

      viewportLayout1.StartWork(ro)
   End Sub

   Private Sub ViewportLayout1OnWorkCompleted(sender As Object, workCompletedEventArgs As WorkCompletedEventArgs)
      Dim ro As ReadOBJ = DirectCast(workCompletedEventArgs.WorkUnit, ReadOBJ)

      ' access/change the loaded items
      Dim entList As Entity() = ro.Entities

      ' add items to the scene
      ro.AddToScene(viewportLayout1)
   End Sub

End Class

DWG/DXF file formats

Dealing with DWG/DXF files in Eyeshot requires several additional steps compared to other standard CAD file formats. As all professional CAD systems do, Eyeshot relies on Open Design Alliance for this file format translation. You'll find all the necessary DLLs inside the Bin folders of the Eyeshot installation.

Basically, the required steps to read/write DWG/DXF files are:

Export

Exporting geometry is straightforward. Assuming you want to write an OBJ file, you need the WriteOBJ class. Depending on the file format the desired unit system may need to be specified. To export the geometry asynchronously use ViewportLayout.StartWork() as explained above for import.

WriteParamsWithMaterials wpwm = new WriteParamsWithMaterials(viewportLayout1);

WriteOBJ wo = new WriteOBJ(wpwm, "fileName.obj");
wo.DoWork();

WriteParamsWithMaterials wpwm = new WriteParamsWithMaterials(viewportLayout1)

Dim wo As WriteOBJ = new WriteOBJ(wpwm, "fileName.obj")
wo.DoWork()

Supported file formats

The following table summarizes the class names/assemblies involved in data translation. You'll find these classes inside the devDept.Eyeshot.Translators namespace.

Table 1: Required classes for geometry import/export.