RenderTarget Class

After a render pass the render target contains the color information of a rendered image.

Render targets represent a linear area of display memory and usually reside in the display memory of the display card. Because of this, RenderTarget objects must be recreated when the device is reset.

To use a RenderTarget, you must:

1. Create the RenderTarget.
   C#

   Copy

   shadowRenderTarget = GfxComponent.CreateRenderTarget(GraphicsDevice,
       1, SurfaceFormat.Single);
   

   C#

   Copy

   public static RenderTarget2D CreateRenderTarget(GraphicsDevice device, 
       int numberLevels, SurfaceFormat surface)
   {
       MultiSampleType type = 
           device.PresentationParameters.MultiSampleType;
   
       // If the card can't use the surface format
       if (!GraphicsAdapter.DefaultAdapter.CheckDeviceFormat(
           DeviceType.Hardware,
           GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Format, 
           TextureUsage.None,
           QueryUsages.None, 
           ResourceType.RenderTarget, 
           surface))
       {
           // Fall back to current display format
           surface = device.DisplayMode.Format;
       }
       // Or it can't accept that surface format 
       // with the current AA settings
       else if (!GraphicsAdapter.DefaultAdapter.CheckDeviceMultiSampleType(
           DeviceType.Hardware, surface, 
           device.PresentationParameters.IsFullScreen, type))
       {
           // Fall back to no antialiasing
           type = MultiSampleType.None;
       }
   
       int width, height;
   
       // See if we can use our buffer size as our texture
       CheckTextureSize(device.PresentationParameters.BackBufferWidth, 
           device.PresentationParameters.BackBufferHeight,
           out width, out height);
   
       // Create our render target
       return new RenderTarget2D(device,
           width, height, numberLevels, surface,
           type, 0);
   
   }
   

2. Set the RenderTarget.
   C#

   Copy

   GraphicsDevice.SetRenderTarget(0, shadowRenderTarget);
   

3. Draw into the RenderTarget.
   C#

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   // Render the shadow map
   GraphicsDevice.Clear(Color.Black);
   DrawScene(MyEffect.shadowMap);
   

4. Reset the original RenderTarget. null as the default render target - i.e. the back buffer.
   C#

   Copy

   // Set render target back to the back buffer
   GraphicsDevice.SetRenderTarget(0, null);
   

5. Call GetTexture to retrieve the contents of the RenderTarget.
   C#

   Copy

   // Return the shadow map as a texture
   return shadowRenderTarget.GetTexture();
   

Concepts

Tasks

Reference