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    3. GroupDocs.Viewer Product Family
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    5. GroupDocs.Viewer for .NET
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    7. Document rendering basics
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    9. Render CAD files
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    11. Render CAD drawings and models

    Render CAD drawings and models as HTML, PDF, and image files

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    GroupDocs.Viewer for .NET allows you to render your CAD drawings and 3D models in HTML, PDF, PNG, and JPEG formats. You do not need to use AutoCAD or other CAD software to load and view CAD files within your .NET application (web or desktop).

    Create a Viewer class instance to get started with the GroupDocs.Viewer API. Pass a CAD drawing you want to view to the class constructor. You can load the drawing from a file or stream. Call one of the Viewer.View method overloads to convert the drawing to HTML, PDF, or image format.

    View CAD files online View demos and examples on GitHub

    Supported CAD file formats

    GroupDocs.Viewer supports the following CAD and 3D file formats:

    GroupDocs.Viewer can detect the document format automatically based on information in the file header.

    Render CAD drawings as HTML

    Create an HtmlViewOptions class instance and pass it to the Viewer.View method to convert a CAD file to HTML. During the conversion, GroupDocs.Viewer creates an SVG image from the CAD drawing and embeds this image in an HTML document.

    The HtmlViewOptions class properties allow you to control the conversion process. For instance, you can embed all external resources in the generated HTML file, minify the output file, and optimize it for printing. Refer to the following documentation section for details: Rendering to HTML.

    Create an HTML file with embedded resources

    To save all elements of an HTML page (including text, graphics, and stylesheets) into a single file, call the HtmlViewOptions.ForEmbeddedResources method and specify the output file name.

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    // Create an HTML file for the drawing.
    // Specify the HTML file name.
    HtmlViewOptions viewOptions = HtmlViewOptions.ForEmbeddedResources("output.html");
    viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            ' Create an HTML file for the drawing.
            ' Specify the HTML file name.
            Dim viewOptions As HtmlViewOptions = HtmlViewOptions.ForEmbeddedResources("output.html")
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    The following image demonstrates the result:

    Render a CAD file to HTML

    Create an HTML file with external resources

    If you want to store an HTML file and additional resource files (such as fonts, images, and style sheets) separately, call the HtmlViewOptions.ForExternalResources method and pass the following parameters:

    • The output file path format
    • The path format for the folder with external resources
    • The resource URL format
    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    // Create an HTML file for the drawing.
    // Specify the HTML file name and location of external resources.
    // {0} is replaced with the resource name.
    HtmlViewOptions viewOptions = HtmlViewOptions.ForExternalResources("output.html", "output/resource_{0}", "output/resource_{0}");
    viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            ' Create an HTML file for the drawing.
            ' Specify the HTML file name and location of external resources.
            ' {0} is replaced with the resource name.
            Dim viewOptions As HtmlViewOptions = HtmlViewOptions.ForExternalResources("output.html", "output/resource_{0}", "output/resource_{0}")
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    The image below demonstrates the result. External resources are placed in a separate folder.

    Place HTML resources in a separate folder

    Render CAD drawings as PDF

    Create a PdfViewOptions class instance and pass it to the Viewer.View method to convert a CAD file to PDF. The PdfViewOptions class properties allow you to control the conversion process. For instance, you can protect the output PDF file, reorder its pages, and specify the quality of document images. Refer to the following documentation section for details: Rendering to PDF.

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    // Create a PDF file for the drawing.
    // Specify the PDF file name.
    PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
    viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            ' Create a PDF file for the drawing.
            ' Specify the PDF file name.
            Dim viewOptions As PdfViewOptions = New PdfViewOptions("output.pdf")
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    The following image demonstrates the result:

    Render a CAD file to PDF

    Render CAD drawings as PNG

    Create a PngViewOptions class instance and pass it to the Viewer.View method to convert a CAD file to PNG. Use the PngViewOptions.Height and PngViewOptions.Width properties to specify the output image size in pixels.

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    // Create a PNG image for the drawing.
    PngViewOptions viewOptions = new PngViewOptions("output.png");
    // Set width and height.
    viewOptions.Width = 1500;
    viewOptions.Height = 1000;
    viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            ' Create a PNG image for the drawing.
            Dim viewOptions As PngViewOptions = New PngViewOptions("output.png")
            ' Set width and height.
            viewOptions.Width = 1500
            viewOptions.Height = 1000
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    The following image demonstrates the result:

    Render a CAD file to PNG

    Render CAD drawings as JPEG

    Create a JpgViewOptions class instance and pass it to the Viewer.View method to convert a CAD file to JPEG. Use the JpgViewOptions.Height and JpgViewOptions.Width properties to specify the output image size in pixels.

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    // Create a JPG image for the drawing.
    JpgViewOptions viewOptions = new JpgViewOptions("output.jpg");
    // Set width and height.
    viewOptions.Width = 1500;
    viewOptions.Height = 1000;
    viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            ' Create a JPG image for the drawing.
            Dim viewOptions As JpgViewOptions = New JpgViewOptions("output.jpg")
            ' Set width and height.
            viewOptions.Width = 1500
            viewOptions.Height = 1000
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    Get information about existing layouts and layers

    Follow the steps below to obtain information about layouts and layers contained in a CAD drawing. You can use this information to specify which layers and layouts to display in the output file.

    1. Create a ViewInfoOptions instance for a specific view.
    2. Call the Viewer.GetViewInfo method, pass the ViewInfoOptions instance to this method as a parameter, and cast the returned object to the CadViewInfo type.
    3. Use the CadViewInfo.Layouts and CadViewInfo.Layers properties to obtain the lists of layouts and layers in the CAD file.
    using System;
using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
using GroupDocs.Viewer.Results;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    ViewInfoOptions viewInfoOptions = ViewInfoOptions.ForHtmlView();
    // Enable this option to see the list of all layouts contained in the CAD file.
    viewInfoOptions.CadOptions.RenderLayouts = true;
    CadViewInfo viewInfo = viewer.GetViewInfo(viewInfoOptions) as CadViewInfo;

    if (viewInfo != null)
    {
        // Display information about the CAD file.
        Console.WriteLine($"File type: {viewInfo.FileType}");
        Console.WriteLine($"The number of pages: {viewInfo.Pages.Count}");

        // Display the list of existing layouts.
        Console.WriteLine("The drawing contains the following layout(s):");
        foreach (Layout layout in viewInfo.Layouts)
            Console.WriteLine(layout.Name);

        // Display the list of existing layers.
        Console.WriteLine("The drawing contains the following layer(s):");
        foreach (Layer layer in viewInfo.Layers)
            Console.WriteLine(layer);
    }
}

    Imports System
Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
Imports GroupDocs.Viewer.Results
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            Dim viewInfoOptions As ViewInfoOptions = ViewInfoOptions.ForHtmlView()
            ' Enable this option to see the list of all layouts contained in the CAD file.
            viewInfoOptions.CadOptions.RenderLayouts = True
            Dim viewInfo As CadViewInfo = TryCast(viewer.GetViewInfo(viewInfoOptions), CadViewInfo)
        
            If viewInfo IsNot Nothing Then
                ' Display information about the CAD file.
                Console.WriteLine($"File type: {viewInfo.FileType}")
                Console.WriteLine($"The number of pages: {viewInfo.Pages.Count}")
        
                ' Display the list of existing layouts.
                Console.WriteLine("The drawing contains the following layout(s):")
                For Each layout As Layout In viewInfo.Layouts
                    Console.WriteLine(layout.Name)
                Next
        
                ' Display the list of existing layers.
                Console.WriteLine("The drawing contains the following layer(s):")
                For Each layer As Layer In viewInfo.Layers
                    Console.WriteLine(layer)
                Next
            End If
        End Using
    End Sub
End Module

    The following image shows a sample console output:

    Get information about a CAD file

    Render all or specific layouts

    When you convert a CAD drawing to HTML, PDF, or image format, GroupDocs.Viewer renders only the model-space layout (Model). If you also need to render all paper space layouts contained in your CAD file, enable the CadOptions.RenderLayouts option for one of the following classes (depending on the output file format):

    Each layout is rendered on a separate page.

    The following example renders all layouts when converting a CAD drawing to PDF:

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("sample.dwg"))
{
   // Convert the document to PDF.
   PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
   // Render the Model and all non-empty paper space layouts. 
   viewOptions.CadOptions.RenderLayouts = true;
   viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("sample.dwg")
            ' Convert the document to PDF.
            Dim viewOptions As PdfViewOptions = New PdfViewOptions("output.pdf")
            ' Render the Model and all non-empty paper space layouts. 
            viewOptions.CadOptions.RenderLayouts = True
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    To render a specific layout, assign the layout name to the CadOptions.LayoutName property of a target view.

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
// ...

using (Viewer viewer = new Viewer("sample.dwg"))
{
   // Convert the document to PDF.
   PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
   // Specify the name of the layout to render.
   // If the specified layout is not found,
   // an exception occurs.
   viewOptions.CadOptions.LayoutName = "Layout1";
   viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("sample.dwg")
            ' Convert the document to PDF.
            Dim viewOptions As PdfViewOptions = New PdfViewOptions("output.pdf")
            ' Specify the name of the layout to render.
            ' If the specified layout is not found,
            ' an exception occurs.
            viewOptions.CadOptions.LayoutName = "Layout1"
            viewer.View(viewOptions)
        End Using
    End Sub
End Module
    Note

    1. The CadOptions.RenderLayouts and CadOptions.LayoutName properties apply only to the following file formats: DWG, DWT, DXF, and DWF.

    2. If you use the CadOptions.LayoutName property to render a specific layout, the CadOptions.RenderLayouts option is ignored.

    Render specific layers

    A CAD drawing can contain many layers. Each layer is used to draw a specific object type. For example, the drawing below contains layers for walls, furniture, plants, and so on. You can control the visibility of objects on the drawing by turning specific layers on or off.

    Layers in a CAD file

    When you convert a CAD drawing to HTML, PDF, or image format, GroupDocs.Viewer renders all available layers. You can specify which layers to display in the output file, as described below:

    1. Access the CadOptions property for a target view:
    1. Assign the list of layers you want to render to the CadOptions.Layers property.

    The following example renders layers with walls and furniture to PDF:

    using GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
using GroupDocs.Viewer.Results;
using System.Collections.Generic;
// ...

using (Viewer viewer = new Viewer("HousePlan.dwg"))
{
    // Convert the document to PDF.
    PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
    // Specify a list of layers to display.
    viewOptions.CadOptions.Layers = new List<Layer>
    {
        new Layer("Base"),
        new Layer("Walls"),
        new Layer("Furniture")
    };
    viewer.View(viewOptions);
}

    Imports GroupDocs.Viewer
Imports GroupDocs.Viewer.Options
Imports GroupDocs.Viewer.Results
Imports System.Collections.Generic
' ...

Module Program
    Sub Main(args As String())
        Using viewer As Viewer = New Viewer("HousePlan.dwg")
            ' Convert the document to PDF.
            Dim viewOptions As PdfViewOptions = New PdfViewOptions("output.pdf")
            ' Specify a list of layers to display.
            viewOptions.CadOptions.Layers = New List(Of Layer) From {
                New Layer("Base"),
                New Layer("Walls"),
                New Layer("Furniture")
                }
            viewer.View(viewOptions)
        End Using
    End Sub
End Module

    The image below illustrates the result.

    Render specific CAD layers

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