public OcclusionCullingScreen(IServiceLocator services)
: base(services)
{
_sceneNodes = new List <SceneNode>();
// Create new occlusion buffer with default settings.
OcclusionBuffer = new OcclusionBuffer(GraphicsService);
OcclusionBuffer.ProgressiveShadowCasterCulling = true;
EnableCulling = true;
// Create a second camera for rendering a top-down view of the scene.
var topDownPerspective = new PerspectiveProjection();
topDownPerspective.SetFieldOfView(MathHelper.ToRadians(90), 1, 1, 512);
_topDownCameraNode = new CameraNode(new Camera(topDownPerspective));
_topDownCameraNode.PoseWorld = new Pose(new Vector3F(-10, 120, -10));
_topDownCameraNode.LookAt(new Vector3F(-10, 0, -10), Vector3F.UnitZ);
_sceneQuery = new CustomSceneQuery();
_debugRenderer = new DebugRenderer(GraphicsService, null, null);
// The DigitalRune Profiler is used to measure execution times.
Profiler.SetFormat("Occlusion.Render", 1e3f, "[ms]");
Profiler.SetFormat("Occlusion.Query", 1e3f, "[ms]");
}
// Needs to be called when occlusion culling gets disabled:
public void ResetShadowCasters()
{
// Shadow casting scene nodes are internally marked as visible/hidden.
// When shadow caster culling disabled, this state needs to be reset.
CopyNodesToList(Scene, _sceneNodes);
OcclusionBuffer.ResetShadowCasters(_sceneNodes);
_sceneNodes.Clear();
}
protected override void Dispose(bool disposing)
{
if (!IsDisposed)
{
if (disposing)
{
OcclusionBuffer.Dispose();
_debugRenderer.Dispose();
}
base.Dispose(disposing);
}
}
protected override void OnRender(RenderContext context)
{
if (ActiveCameraNode == null)
{
return;
}
context.Scene = Scene;
context.CameraNode = ActiveCameraNode;
context.LodCameraNode = ActiveCameraNode;
// Copy all scene nodes into a list.
CopyNodesToList(Scene, _sceneNodes);
// ----- Occlusion Culling
// Usually, we would make a scene query to get all scene nodes within the
// viewing frustum. But in this example we will use the new OcclusionBuffer.
if (EnableCulling)
{
// Render all occluders into the occlusion buffer.
// - "_sceneNodes" is a list of all scene nodes. The OcclusionBuffer will
// go through the list and render all occluders.
// - "LightNode" is the main directional light that casts a cascaded shadow.
// Passing the light node to the OcclusionBuffer activates shadow caster
// culling.
// - A custom scene node renderer can be passed to the OcclusionBuffer. In
// this example, the ground mesh "Gravel/Gravel.fbx" has a material with an
// "Occluder" render pass. When we pass the "MeshRenderer" to the OcclusionBuffer
// the ground mesh will be rendered directly into the occlusion buffer.
Profiler.Start("Occlusion.Render");
context.RenderPass = "******";
OcclusionBuffer.Render(_sceneNodes, LightNode, MeshRenderer, context);
context.RenderPass = null;
Profiler.Stop("Occlusion.Render");
// Perform occlusion culling on the specified list of scene nodes.
// - The scene nodes will be tested against the occluders. If a scene node
// is hidden, it will be replaced with a null entry in the list.
// - When shadow caster culling is active, shadow casting scene nodes will
// also be tested against the occluders. If the shadow is not visible,
// the shadow caster will internally be marked as occluded. The ShadowMapRenderer
// will automatically skip occluded scene nodes.
Profiler.Start("Occlusion.Query");
OcclusionBuffer.Query(_sceneNodes, context);
Profiler.Stop("Occlusion.Query");
}
// The base DeferredGraphicsScreen expects a CustomSceneQuery.
// --> Copy the occlusion culling results to a CustomSceneQuery.
_sceneQuery.Set(ActiveCameraNode, _sceneNodes, context);
var renderTargetPool = GraphicsService.RenderTargetPool;
var graphicsDevice = GraphicsService.GraphicsDevice;
var originalRenderTarget = context.RenderTarget;
var fullViewport = context.Viewport;
RenderTarget2D topDownRenderTarget = null;
const int topDownViewSize = 384;
if (ShowTopDownView)
{
// Render top-down scene into an offscreen render target.
var format = new RenderTargetFormat(context.RenderTarget)
{
Width = topDownViewSize,
Height = topDownViewSize,
};
topDownRenderTarget = renderTargetPool.Obtain2D(format);
context.Scene = Scene;
context.CameraNode = _topDownCameraNode;
context.Viewport = new Viewport(0, 0, topDownViewSize, topDownViewSize);
context.RenderTarget = topDownRenderTarget;
RenderScene(_sceneQuery, context, true, false, false, false);
_debugRenderer.Clear();
_debugRenderer.DrawObject(ActiveCameraNode, Color.Red, true, true);
_debugRenderer.Render(context);
context.RenderTarget = originalRenderTarget;
context.Viewport = fullViewport;
}
// Render regular 3D scene.
context.Scene = Scene;
context.CameraNode = ActiveCameraNode;
RenderScene(_sceneQuery, context, true, false, true, false);
// Render debug visualization on top of scene.
bool renderObject = false;
switch (DebugVisualization)
{
case DebugVisualization.CameraHzb:
OcclusionBuffer.VisualizeCameraBuffer(DebugLevel, context);
break;
case DebugVisualization.LightHzb:
OcclusionBuffer.VisualizeLightBuffer(DebugLevel, context);
break;
case DebugVisualization.Object:
OcclusionBuffer.VisualizeObject(DebugObject, context);
renderObject = true;
break;
case DebugVisualization.ShadowCaster:
OcclusionBuffer.VisualizeShadowCaster(DebugObject, context);
break;
case DebugVisualization.ShadowVolume:
OcclusionBuffer.VisualizeShadowVolume(DebugObject, context);
renderObject = true;
break;
}
if (renderObject)
{
_debugRenderer.Clear();
_debugRenderer.DrawObject(DebugObject, Color.Yellow, true, true);
_debugRenderer.Render(context);
}
if (ShowTopDownView)
{
// Copy offscreen buffer to screen.
context.Viewport = fullViewport;
graphicsDevice.Viewport = fullViewport;
SpriteBatch.Begin(SpriteSortMode.Immediate, BlendState.Opaque, SamplerState.PointClamp, DepthStencilState.None, RasterizerState.CullNone);
SpriteBatch.Draw(
topDownRenderTarget,
new Rectangle(fullViewport.Width - topDownViewSize, fullViewport.Height - topDownViewSize, topDownViewSize, topDownViewSize),
Color.White);
SpriteBatch.End();
renderTargetPool.Recycle(topDownRenderTarget);
}
// Clean-up
_sceneNodes.Clear();
_sceneQuery.Reset();
context.Scene = null;
context.CameraNode = null;
context.LodCameraNode = null;
}
