RenderCADAsImages.cs

// For complete examples and data files, please go to https://github.com/groupdocs-viewer/GroupDocs.Viewer-for-.NET
//Get Configurations
ViewerConfig config = Utilities.GetConfigurations();

// Create image handler 
ViewerImageHandler imageHandler = new ViewerImageHandler(config);

// Guid implies that unique document name 
string guid = DocumentName;

// Set Cad options to render content with a specified size
ImageOptions options = new ImageOptions();

options.CadOptions.Height = 750;
options.CadOptions.Width = 450;

//Get document pages in image form
List<PageImage> Images = imageHandler.GetPages(guid, options);

foreach (PageImage image in Images)
{
    //Save each image at disk
    Utilities.SaveAsImage(image.PageNumber + "_" + DocumentName, image.Stream);
}