DepthStencilBuffer Class

A depth stencil buffer is where depth and stencil data are kept for a render target. The depth buffer is used to determine which 3D objects appear behind other 3D objects; the stencil buffer is used for special effects. Depth stencil buffers are often created at the same time render targets are created. Depth stencil buffers must be recreated when the device is reset. The DepthStencilBuffer property on GraphicsDevice points to the current DepthStencilBuffer.

To use a DepthStencilBuffer, you must:

1. Create the DepthStencilBuffer.
   C#

   Copy

   shadowDepthBuffer = GfxComponent.CreateDepthStencil(shadowRenderTarget,
       DepthFormat.Depth24Stencil8Single);
   

   C#

   Copy

   public static DepthStencilBuffer CreateDepthStencil(RenderTarget2D target)
   {
       return new DepthStencilBuffer(target.GraphicsDevice, target.Width,
           target.Height, target.GraphicsDevice.DepthStencilBuffer.Format,
           target.MultiSampleType, target.MultiSampleQuality);
   }
   public static DepthStencilBuffer CreateDepthStencil(RenderTarget2D target, DepthFormat depth)
   {
       if (GraphicsAdapter.DefaultAdapter.CheckDepthStencilMatch(DeviceType.Hardware,
          GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Format, target.Format,
           depth))
       {
           return new DepthStencilBuffer(target.GraphicsDevice, target.Width,
               target.Height, depth, target.MultiSampleType, target.MultiSampleQuality);
       }
       else
           return CreateDepthStencil(target);
   }
   

2. Set the DepthStencilBuffer using DepthStencilBuffer. It is a good idea to cache the current DepthStencilBuffer beforehand.
   C#

   Copy

   // Cache the current depth buffer
   DepthStencilBuffer old = GraphicsDevice.DepthStencilBuffer;
   // Set our custom depth buffer
   GraphicsDevice.DepthStencilBuffer = shadowDepthBuffer;
   

3. Draw into your DepthStencilBuffer.
   C#

   Copy

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

4. Reset the original DepthStencilBuffer.
   C#

   Copy

   // Reset the depth buffer
   GraphicsDevice.DepthStencilBuffer = old;
   

Custom depth stencil buffers are normally used in conjunction with a custom RenderTarget. How To: Create a Depth Texture has an example of this.

Concepts

Tasks

Reference