Vista - Render Visuals in ASP.NET

I'm trying to create a 3D scene in an ASP.NET application, then generate a
GIF to send to the browser.

I create a Viewport3DVisual, set up the camera and add childrten. This
works, since it render if I add it to a windows Window.

To generate the image I use RenderTargetBitmap.Render. This also work in a
windows Window.

In the ASP.NET HttpHandler which output the image. I've tried
RenderTargetBitmap.Render(Viewport3DVisual) which generates a black image. I
can simmulate this in a windows application by saving the image before the
windows is rendered.

I assume (after some Reflector-ing) that the visual need a context to render
in, and thats why it's not rendered. How do I get the visuals to render?

In theory, what you're describing should work. That is, you should be able
to build a 3d scene in a Viewport3DVisual and immediate render it to a
RenderTargetBitmap. We'll see if we can reproduce this issue. Which CTP
are you using? Also, are any of the Materials in your 3d scene
VisualBrushes? Neither *should* matter, but it'd be good to know.

Thanks,
-Adam Smith [MS]

"Willie" <Willie@discussions.microsoft.com> wrote in message
news:7F36A0B6-5536-400F-AA47-6D6CEE147651@microsoft.com...
> I'm trying to create a 3D scene in an ASP.NET application, then generate a
> GIF to send to the browser.
>
> I create a Viewport3DVisual, set up the camera and add childrten. This
> works, since it render if I add it to a windows Window.
>
> To generate the image I use RenderTargetBitmap.Render. This also work in a
> windows Window.
>
> In the ASP.NET HttpHandler which output the image. I've tried
> RenderTargetBitmap.Render(Viewport3DVisual) which generates a black image.
> I
> can simmulate this in a windows application by saving the image before the
> windows is rendered.
>
> I assume (after some Reflector-ing) that the visual need a context to
> render
> in, and thats why it's not rendered. How do I get the visuals to render?

I'm using the December CTP (I've read that there were no changes to the
Avalon binaries in the Jan CTP, so I didn't bother with the 1GB download).

I don’t use any VisualBrushe’s in the ViewPort3D.

Below is a windows Window class to simulate the problem. The SaveToDisk in
the constructor does not work, it just generates a balnk image. The second
one, in the Actived event does work.


public partial class Window2 : Window
{

private Viewport3D viewport3D = new Viewport3D();

public Window2()
{
InitializeComponent();
this.Activated += new EventHandler(OnActivatedHandler);

PerspectiveCamera camera = new PerspectiveCamera(new Point3D(0,
0, 7), new Vector3D(0, 0, -7), new Vector3D(0, 1, 0), 40);
camera.FarPlaneDistance = 20;
camera.NearPlaneDistance = 1;
viewport3D.Camera = camera;

ModelVisual3D visual3D = new ModelVisual3D();
visual3D.Content = new DirectionalLight(Colors.White, new
Vector3D(0, 0, -5));

Cylinder3D cylinder = new Cylinder3D();
DiffuseMaterial material = new DiffuseMaterial();
material.Brush = Brushes.Blue;
cylinder.Material = material;
visual3D.Children.Add(cylinder);

viewport3D.Children.Add(visual3D);

this.AddChild(viewport3D);

SaveToDisk(viewport3D, "c:\\inConstrictor.jpg"); //THIS DOES NOT
WORK
}

protected void OnActivatedHandler(object sender, EventArgs e)
{
SaveToDisk(this.viewport3D, "c:\\inActivated.jpg"); //THIS WORKS
}

private void SaveToDisk(Visual visual, String fileName)
{
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
RenderTargetBitmap rtb = new RenderTargetBitmap(800, 800, 96d,
96d, PixelFormats.Default);
rtb.Render(visual);
BitmapFrame frame = BitmapFrame.Create(rtb);
encoder.Frames.Add(frame);
FileStream file = new FileStream(fileName, FileMode.Create);
encoder.Save(file);
file.Close();
}

}


Thanks


"Adam Smith [MS]" wrote:

> In theory, what you're describing should work. That is, you should be able
> to build a 3d scene in a Viewport3DVisual and immediate render it to a
> RenderTargetBitmap. We'll see if we can reproduce this issue. Which CTP
> are you using? Also, are any of the Materials in your 3d scene
> VisualBrushes? Neither *should* matter, but it'd be good to know.
>
> Thanks,
> -Adam Smith [MS]
>
> "Willie" <Willie@discussions.microsoft.com> wrote in message
> news:7F36A0B6-5536-400F-AA47-6D6CEE147651@microsoft.com...
> > I'm trying to create a 3D scene in an ASP.NET application, then generate a
> > GIF to send to the browser.
> >
> > I create a Viewport3DVisual, set up the camera and add childrten. This
> > works, since it render if I add it to a windows Window.
> >
> > To generate the image I use RenderTargetBitmap.Render. This also work in a
> > windows Window.
> >
> > In the ASP.NET HttpHandler which output the image. I've tried
> > RenderTargetBitmap.Render(Viewport3DVisual) which generates a black image.
> > I
> > can simmulate this in a windows application by saving the image before the
> > windows is rendered.
> >
> > I assume (after some Reflector-ing) that the visual need a context to
> > render
> > in, and thats why it's not rendered. How do I get the visuals to render?
>
>
>