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

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

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

• AutoCAD Drawing (.DWG)
• AutoCAD Drawing Template (.DWT)
• Design Web Format (.DWF)
• Drawing Exchange Format (.DXF)
• AutoCAD Plotter Document (.PLT)
• MicroStation Design File (V7) (.DGN)
• Industry Foundation Classes (.IFC)
• Stereolithography File (.STL)
• Wavefront 3D Object File (.OBJ)
• Common File Format (.CF2)
• IGES (Initial Graphics Exchange Specification) Drawing (.IGS)
• HPGL (Hewlett-Packard Graphics Language) Plot File (.HPG)

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

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.

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

The following image demonstrates the result:

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 (var 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.
    var viewOptions = HtmlViewOptions.ForExternalResources("output.html", "output/resource_{0}", "output/resource_{0}");
    viewer.View(viewOptions);
}

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

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

The following image demonstrates the result:

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

The following image demonstrates the result:

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

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 GroupDocs.Viewer;
using GroupDocs.Viewer.Options;
using GroupDocs.Viewer.Results;

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

The following image shows a sample console output:

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):

• HtmlViewOptions
• PdfViewOptions
• PngViewOptions
• JpgViewOptions

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

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 (var viewer = new Viewer("sample.dwg"))
{
   // Convert the document to PDF.
   var 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);
}

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.

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.

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:

• HtmlViewOptions
• PdfViewOptions
• PngViewOptions
• JpgViewOptions

2. 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 (var viewer = new Viewer("HousePlan.dwg"))
{
    // Convert the document to PDF.
    var 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);
}

The image below illustrates the result.