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

GroupDocs.Viewer for Java 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 Java 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:

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.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.HtmlViewOptions;
// ...

try (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);
}

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
import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.HtmlViewOptions;
// ...

try (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);
}

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.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PdfViewOptions;
// ...

try (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);
}

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.setHeight and PngViewOptions.setWidth methods to specify the output image size in pixels.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PngViewOptions;
// ...

try (Viewer viewer = new Viewer("HousePlan.dwg")) {
    // Create a PNG image for the drawing.
    PngViewOptions viewOptions = new PngViewOptions("output.png");
    // Set width and height.
    viewOptions.setWidth(1500);
    viewOptions.setHeight(1000);
    viewer.view(viewOptions);
}

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.setHeight and JpgViewOptions.setWidth methods to specify the output image size in pixels.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PngViewOptions;
// ...

try (Viewer viewer = new Viewer("HousePlan.dwg")) {
    // Create a JPG image for the drawing.
    PngViewOptions viewOptions = new PngViewOptions("output.png");
    // Set width and height.
    viewOptions.setWidth(1500);
    viewOptions.setHeight(1000);
    viewer.view(viewOptions);
}

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.getLayouts and CadViewInfo.getLayers properties to obtain the lists of layouts and layers in the CAD file.
import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.ViewInfoOptions;
import com.groupdocs.viewer.results.CadViewInfo;
import com.groupdocs.viewer.results.Layer;
import com.groupdocs.viewer.results.Layout;
// ...
CadViewInfo info;
try (Viewer viewer = new Viewer("HousePlan.dwg")) {
    info = (CadViewInfo) viewer.getViewInfo(ViewInfoOptions.forHtmlView());
}
// Display information about the CAD file.
System.out.println("File type: " + info.getFileType());
System.out.println("The number of pages: " + info.getPages().size());
// Display the list of existing layouts.
for (Layout layout : info.getLayouts()) {
    System.out.println(layout);
}
// Display the list of existing layers.
for (Layer layer : info.getLayers()) {
    System.out.println(layer);
}

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, use the CadOptions.setRenderLayouts method 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:

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PdfViewOptions;
// ...

try (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.getCadOptions().setRenderLayouts(true);
    viewer.view(viewOptions);
}

To render a specific layout, pass the layout name to the CadOptions.setLayoutName method of a target view.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PdfViewOptions;
// ...

try (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.getCadOptions().setLayoutName("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.setLayoutName method 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. Use the setCadOptions method for a target view:
  1. Assign the list of layers you want to render to the CadOptions.setLayers method.

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

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PdfViewOptions;
// ...

try (Viewer viewer = new Viewer("HousePlan.dwg")) {
    // Convert the document to PDF.
    PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
    // Specify a list of layers to display.
    List<Layer> layers = new ArrayList<>();
    layers.add(CacheableFactory.getInstance().newLayer("Base"));
    layers.add(CacheableFactory.getInstance().newLayer("Walls"));
    layers.add(CacheableFactory.getInstance().newLayer("Furniture"));
    viewOptions.getCadOptions().setLayers(layers);

    viewOptions.getCadOptions().setLayoutName("Layout1");
    viewer.view(viewOptions);
}

The image below illustrates the result.

Render specific CAD layers