/// <summary>
/// This renders the refraction map;
/// </summary>
private void DrawRefractionMap(GraphicsDevice device, Camera camera, RenderSceneDelegate RenderScene)
{
// Clipping computations will be done after vertices have passed through the vertex shader and are in screen space. We must therefore represent the clipping planes
// screen space as well, which is achieved by multiplying the plane coefficients by the view and projection matrices.
Vector4 refractionPlaneCoefficients = new Vector4(0.0f, 1.0f, 0.0f, -waterHeight);
refractionPlaneCoefficients = Vector4.Transform(refractionPlaneCoefficients, Matrix.Transpose(Matrix.Invert(camera.ViewMatrix * camera.ProjMatrix)));
refractionClippingPlane = new Plane(refractionPlaneCoefficients);
// Prepare the device for rendering to the desired render target
device.ClipPlanes[0].Plane = refractionClippingPlane;
device.ClipPlanes[0].IsEnabled = true;
device.SetRenderTarget(0, refractionRenderTarget);
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.Black, 1.0f, 0);
// Render the scene with clipping
RenderScene();
// Now disable the clipping plane and save the result to a texture
device.ClipPlanes[0].IsEnabled = false;
device.SetRenderTarget(0, null);
refractionMap = refractionRenderTarget.GetTexture();
}
/// <summary>
/// This renders the refraction map;
/// </summary>
private void DrawRefractionMap(GraphicsDevice device, Camera camera, RenderSceneDelegate RenderScene)
{
// Clipping computations will be done after vertices have passed through the vertex shader and are in screen space. We must therefore represent the clipping planes
// screen space as well, which is achieved by multiplying the plane coefficients by the view and projection matrices.
Vector4 refractionPlaneCoefficients = new Vector4(0.0f, 1.0f, 0.0f, -waterHeight);
refractionPlaneCoefficients = Vector4.Transform(refractionPlaneCoefficients, Matrix.Transpose(Matrix.Invert(camera.ViewMatrix * camera.ProjMatrix)));
refractionClippingPlane = new Plane(refractionPlaneCoefficients);
// Prepare the device for rendering to the desired render target
device.ClipPlanes[0].Plane = refractionClippingPlane;
device.ClipPlanes[0].IsEnabled = true;
device.SetRenderTarget(0, refractionRenderTarget);
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.Black, 1.0f, 0);
// Render the scene with clipping
RenderScene();
// Now disable the clipping plane and save the result to a texture
device.ClipPlanes[0].IsEnabled = false;
device.SetRenderTarget(0, null);
refractionMap = refractionRenderTarget.GetTexture();
}
/// <summary>
/// This draws the scene with reflective and refractive water. It takes a delegate function to perform the actual scene rendering needed to construct the refraction
/// and reflection maps.
/// </summary>
/// <param name="camera"></param>
public void Draw(Camera camera, RenderSceneDelegate RenderScene)
{
GraphicsDevice graphicsDevice = game.GraphicsDevice;
// Render the refraction and reflection maps
DrawRefractionMap(graphicsDevice, camera, RenderScene);
}
/// <summary>
/// This draws the scene with reflective and refractive water. It takes a delegate function to perform the actual scene rendering needed to construct the refraction
/// and reflection maps.
/// </summary>
/// <param name="camera"></param>
public void Draw(Camera camera, RenderSceneDelegate RenderScene)
{
GraphicsDevice graphicsDevice = game.GraphicsDevice;
// Render the refraction and reflection maps
DrawRefractionMap(graphicsDevice, camera, RenderScene);
}