[SLH]

Hi,

RenderToBitmap takes a long time (~60 seconds consistently) to render a 2048x2048 image. This seems excessive as in the onscreen view I can render in realtime. 

Is this expected behaviour? If so, are there any workarounds for it?

I'm calling this routine:
public RenderTargetBitmap RenderToBitmap(Brush backgroundBrush = null, int dpi = 96);

Code:

     var viewport3D = new Viewport3D();

     viewport3D.Width = 2048;
     viewport3D.Height = 2048;

     var camera = new FirstPersonCamera();
     camera.Position = new Point3D(0, 0, 0);
     camera.Bank = 0;
     camera.Heading = 0;
     camera.Attitude = -90;
     camera.FieldOfView = 92;
     camera.TargetViewport3D = viewport3D;

     var displayModels = objs.AsModel3DGroup();

     foreach (var m in objs.Values)
     {
         viewport3D.Children.Add(m.CreateModelVisual3D());
     }

     camera.Refresh();

     Stopwatch renderStopWatch = new Stopwatch();
     renderStopWatch.Start();

     var img = camera.RenderToBitmap(backgroundBrush);    

     renderStopWatch.Stop();