Extract bounded additional scene lights

engine/include/XCEngine/Rendering/RenderSceneExtractor.h

@@ -5,6 +5,7 @@
 #include <XCEngine/Rendering/RenderCameraData.h>
 #include <XCEngine/Rendering/VisibleRenderObject.h>
 
+#include <array>
 #include <cstdint>
 #include <vector>
 
@@ -29,6 +30,24 @@ struct RenderDirectionalLightData {
     Math::Color color = Math::Color::White();
 };
 
+enum class RenderLightType : uint32_t {
+    Directional = 0,
+    Point = 1,
+    Spot = 2
+};
+
+struct RenderAdditionalLightData {
+    RenderLightType type = RenderLightType::Point;
+    bool enabled = false;
+    bool castsShadows = false;
+    Math::Color color = Math::Color::White();
+    float intensity = 1.0f;
+    Math::Vector3 position = Math::Vector3::Zero();
+    Math::Vector3 direction = Math::Vector3::Back();
+    float range = 0.0f;
+    float spotAngle = 0.0f;
+};
+
 struct RenderDirectionalShadowData {
     bool enabled = false;
     Math::Matrix4x4 viewProjection = Math::Matrix4x4::Identity();
@@ -41,8 +60,12 @@ struct RenderDirectionalShadowData {
 };
 
 struct RenderLightingData {
+    static constexpr uint32_t kMaxAdditionalLightCount = 8u;
+
     RenderDirectionalLightData mainDirectionalLight;
     RenderDirectionalShadowData mainDirectionalShadow;
+    std::array<RenderAdditionalLightData, kMaxAdditionalLightCount> additionalLights = {};
+    uint32_t additionalLightCount = 0u;
 
     bool HasMainDirectionalLight() const {
         return mainDirectionalLight.enabled;
@@ -51,6 +74,10 @@ struct RenderLightingData {
     bool HasMainDirectionalShadow() const {
         return mainDirectionalShadow.IsValid();
     }
+
+    bool HasAdditionalLights() const {
+        return additionalLightCount > 0u;
+    }
 };
 
 struct RenderSceneData {
@@ -81,6 +108,8 @@ public:
 private:
     void ExtractLighting(
         const Components::Scene& scene,
+        const Math::Vector3& cameraPosition,
+        uint32_t cullingMask,
         RenderLightingData& lightingData) const;
     void ExtractVisibleItems(
         Components::GameObject* gameObject,

engine/include/XCEngine/Rendering/RenderSceneUtility.h

@@ -11,6 +11,7 @@ namespace XCEngine {
 namespace Components {
 class CameraComponent;
 class GameObject;
+class LightComponent;
 class Scene;
 } // namespace Components
 
@@ -31,5 +32,18 @@ std::vector<VisibleRenderItem> CollectRenderItemsForEntityIds(
     const std::vector<uint64_t>& entityIds,
     const Math::Vector3& cameraPosition);
 
+bool IsUsableLight(const Components::LightComponent* light);
+
+bool IsLightVisibleForCullingMask(
+    const Components::LightComponent& light,
+    uint32_t cullingMask);
+
+Math::Vector3 BuildRenderLightDirection(
+    const Components::LightComponent& light);
+
+Components::LightComponent* FindMainDirectionalLight(
+    const Components::Scene& scene,
+    uint32_t cullingMask = 0xFFFFFFFFu);
+
 } // namespace Rendering
 } // namespace XCEngine

engine/src/Rendering/RenderSceneExtractor.cpp

@@ -21,11 +21,95 @@ bool IsUsableCamera(const Components::CameraComponent* camera) {
            camera->GetGameObject()->IsActiveInHierarchy();
 }
 
-bool IsUsableLight(const Components::LightComponent* light) {
-    return light != nullptr &&
-           light->IsEnabled() &&
-           light->GetGameObject() != nullptr &&
-           light->GetGameObject()->IsActiveInHierarchy();
+RenderLightType ToRenderLightType(Components::LightType lightType) {
+    switch (lightType) {
+        case Components::LightType::Directional:
+            return RenderLightType::Directional;
+        case Components::LightType::Point:
+            return RenderLightType::Point;
+        case Components::LightType::Spot:
+            return RenderLightType::Spot;
+    }
+
+    return RenderLightType::Point;
+}
+
+RenderDirectionalLightData BuildDirectionalLightData(
+    const Components::LightComponent& light) {
+    RenderDirectionalLightData lightData;
+    lightData.enabled = true;
+    lightData.castsShadows = light.GetCastsShadows();
+    lightData.intensity = light.GetIntensity();
+    lightData.color = light.GetColor();
+    lightData.direction = BuildRenderLightDirection(light);
+    return lightData;
+}
+
+RenderAdditionalLightData BuildAdditionalLightData(
+    const Components::LightComponent& light) {
+    RenderAdditionalLightData lightData;
+    lightData.type = ToRenderLightType(light.GetLightType());
+    lightData.enabled = true;
+    lightData.castsShadows = light.GetCastsShadows();
+    lightData.color = light.GetColor();
+    lightData.intensity = light.GetIntensity();
+
+    switch (light.GetLightType()) {
+        case Components::LightType::Directional:
+            lightData.direction = BuildRenderLightDirection(light);
+            break;
+        case Components::LightType::Point:
+            lightData.position = light.transform().GetPosition();
+            lightData.range = light.GetRange();
+            break;
+        case Components::LightType::Spot:
+            lightData.position = light.transform().GetPosition();
+            lightData.direction = BuildRenderLightDirection(light);
+            lightData.range = light.GetRange();
+            lightData.spotAngle = light.GetSpotAngle();
+            break;
+    }
+
+    return lightData;
+}
+
+float ComputeAdditionalLightInfluence(
+    const Components::LightComponent& light,
+    const Math::Vector3& cameraPosition) {
+    if (light.GetIntensity() <= Math::EPSILON) {
+        return 0.0f;
+    }
+
+    if (light.GetLightType() == Components::LightType::Directional) {
+        return light.GetIntensity();
+    }
+
+    const float range = std::max(light.GetRange(), 0.001f);
+    const float rangeSq = range * range;
+    const Math::Vector3 lightPosition = light.transform().GetPosition();
+    const float distanceSq = (lightPosition - cameraPosition).SqrMagnitude();
+    if (distanceSq >= rangeSq) {
+        return 0.0f;
+    }
+
+    return light.GetIntensity() / std::max(distanceSq, Math::EPSILON);
+}
+
+uint32_t GetAdditionalLightGroupRank(const Components::LightComponent& light) {
+    return light.GetLightType() == Components::LightType::Directional ? 0u : 1u;
+}
+
+uint32_t GetAdditionalLightTypeRank(const Components::LightComponent& light) {
+    switch (light.GetLightType()) {
+        case Components::LightType::Directional:
+            return 0u;
+        case Components::LightType::Point:
+            return 1u;
+        case Components::LightType::Spot:
+            return 2u;
+    }
+
+    return 3u;
 }
 
 bool CompareVisibleItems(const VisibleRenderItem& lhs, const VisibleRenderItem& rhs) {
@@ -73,7 +157,7 @@ RenderSceneData RenderSceneExtractor::Extract(
         sceneData.visibleItems.begin(),
         sceneData.visibleItems.end(),
         CompareVisibleItems);
-    ExtractLighting(scene, sceneData.lighting);
+    ExtractLighting(scene, cameraPosition, cullingMask, sceneData.lighting);
 
     return sceneData;
 }
@@ -102,7 +186,7 @@ RenderSceneData RenderSceneExtractor::ExtractForCamera(
         sceneData.visibleItems.begin(),
         sceneData.visibleItems.end(),
         CompareVisibleItems);
-    ExtractLighting(scene, sceneData.lighting);
+    ExtractLighting(scene, cameraPosition, cullingMask, sceneData.lighting);
 
     return sceneData;
 }
@@ -144,43 +228,73 @@ Components::CameraComponent* RenderSceneExtractor::SelectCamera(
 
 void RenderSceneExtractor::ExtractLighting(
     const Components::Scene& scene,
+    const Math::Vector3& cameraPosition,
+    uint32_t cullingMask,
     RenderLightingData& lightingData) const {
+    lightingData = {};
+
     const std::vector<Components::LightComponent*> lights =
         scene.FindObjectsOfType<Components::LightComponent>();
 
-    Components::LightComponent* mainDirectionalLight = nullptr;
+    Components::LightComponent* mainDirectionalLight =
+        FindMainDirectionalLight(scene, cullingMask);
+    if (mainDirectionalLight != nullptr) {
+        lightingData.mainDirectionalLight = BuildDirectionalLightData(*mainDirectionalLight);
+    }
+
+    struct AdditionalLightCandidate {
+        RenderAdditionalLightData data = {};
+        float influence = 0.0f;
+        uint32_t groupRank = 0u;
+        uint32_t typeRank = 0u;
+        Components::GameObject::ID gameObjectId = Components::GameObject::INVALID_ID;
+    };
+
+    std::vector<AdditionalLightCandidate> candidates;
+    candidates.reserve(lights.size());
     for (Components::LightComponent* light : lights) {
-        if (!IsUsableLight(light) ||
-            light->GetLightType() != Components::LightType::Directional) {
+        if (light == nullptr ||
+            !IsLightVisibleForCullingMask(*light, cullingMask) ||
+            light == mainDirectionalLight) {
             continue;
         }
 
-        if (mainDirectionalLight == nullptr ||
-            light->GetIntensity() > mainDirectionalLight->GetIntensity()) {
-            mainDirectionalLight = light;
-        }
+        AdditionalLightCandidate candidate;
+        candidate.data = BuildAdditionalLightData(*light);
+        candidate.influence = ComputeAdditionalLightInfluence(*light, cameraPosition);
+        candidate.groupRank = GetAdditionalLightGroupRank(*light);
+        candidate.typeRank = GetAdditionalLightTypeRank(*light);
+        candidate.gameObjectId = light->GetGameObject() != nullptr
+            ? light->GetGameObject()->GetID()
+            : Components::GameObject::INVALID_ID;
+        candidates.push_back(candidate);
     }
 
-    if (mainDirectionalLight == nullptr) {
-        lightingData = {};
-        return;
+    std::sort(
+        candidates.begin(),
+        candidates.end(),
+        [](const AdditionalLightCandidate& lhs, const AdditionalLightCandidate& rhs) {
+            if (lhs.groupRank != rhs.groupRank) {
+                return lhs.groupRank < rhs.groupRank;
+            }
+
+            if (lhs.influence != rhs.influence) {
+                return lhs.influence > rhs.influence;
+            }
+
+            if (lhs.typeRank != rhs.typeRank) {
+                return lhs.typeRank < rhs.typeRank;
+            }
+
+            return lhs.gameObjectId < rhs.gameObjectId;
+        });
+
+    const uint32_t additionalLightCount = static_cast<uint32_t>(
+        std::min(candidates.size(), static_cast<size_t>(RenderLightingData::kMaxAdditionalLightCount)));
+    lightingData.additionalLightCount = additionalLightCount;
+    for (uint32_t index = 0; index < additionalLightCount; ++index) {
+        lightingData.additionalLights[index] = candidates[index].data;
     }
-
-    RenderDirectionalLightData lightData;
-    lightData.enabled = true;
-    lightData.castsShadows = mainDirectionalLight->GetCastsShadows();
-    lightData.intensity = mainDirectionalLight->GetIntensity();
-    lightData.color = mainDirectionalLight->GetColor();
-
-    Math::Vector3 direction = mainDirectionalLight->transform().GetForward() * -1.0f;
-    if (direction.SqrMagnitude() <= Math::EPSILON) {
-        direction = Math::Vector3::Back();
-    } else {
-        direction = direction.Normalized();
-    }
-    lightData.direction = direction;
-
-    lightingData.mainDirectionalLight = lightData;
 }
 
 void RenderSceneExtractor::ExtractVisibleItems(

engine/src/Rendering/RenderSceneUtility.cpp

@@ -2,6 +2,7 @@
 
 #include "Components/CameraComponent.h"
 #include "Components/GameObject.h"
+#include "Components/LightComponent.h"
 #include "Components/MeshFilterComponent.h"
 #include "Components/MeshRendererComponent.h"
 #include "Components/TransformComponent.h"
@@ -139,5 +140,57 @@ std::vector<VisibleRenderItem> CollectRenderItemsForEntityIds(
     return visibleItems;
 }
 
+bool IsUsableLight(const Components::LightComponent* light) {
+    return light != nullptr &&
+           light->IsEnabled() &&
+           light->GetGameObject() != nullptr &&
+           light->GetGameObject()->IsActiveInHierarchy();
+}
+
+bool IsLightVisibleForCullingMask(
+    const Components::LightComponent& light,
+    uint32_t cullingMask) {
+    if (!IsUsableLight(&light)) {
+        return false;
+    }
+
+    const Components::GameObject* gameObject = light.GetGameObject();
+    const uint32_t gameObjectLayerMask = 1u << gameObject->GetLayer();
+    return (cullingMask & gameObjectLayerMask) != 0u;
+}
+
+Math::Vector3 BuildRenderLightDirection(
+    const Components::LightComponent& light) {
+    Math::Vector3 direction = light.transform().GetForward() * -1.0f;
+    if (direction.SqrMagnitude() <= Math::EPSILON) {
+        return Math::Vector3::Back();
+    }
+
+    return direction.Normalized();
+}
+
+Components::LightComponent* FindMainDirectionalLight(
+    const Components::Scene& scene,
+    uint32_t cullingMask) {
+    const std::vector<Components::LightComponent*> lights =
+        scene.FindObjectsOfType<Components::LightComponent>();
+
+    Components::LightComponent* mainDirectionalLight = nullptr;
+    for (Components::LightComponent* light : lights) {
+        if (light == nullptr ||
+            !IsLightVisibleForCullingMask(*light, cullingMask) ||
+            light->GetLightType() != Components::LightType::Directional) {
+            continue;
+        }
+
+        if (mainDirectionalLight == nullptr ||
+            light->GetIntensity() > mainDirectionalLight->GetIntensity()) {
+            mainDirectionalLight = light;
+        }
+    }
+
+    return mainDirectionalLight;
+}
+
 } // namespace Rendering
 } // namespace XCEngine

engine/src/Rendering/SceneRenderRequestPlanner.cpp

@@ -1,12 +1,19 @@
 #include "Rendering/SceneRenderRequestPlanner.h"
 
+#include "Components/GameObject.h"
 #include "Components/LightComponent.h"
+#include "Components/MeshFilterComponent.h"
+#include "Components/MeshRendererComponent.h"
 #include "Core/Math/Matrix4.h"
+#include "Core/Math/Quaternion.h"
+#include "Rendering/RenderSceneUtility.h"
 #include "Rendering/SceneRenderRequestUtils.h"
 
 #include "Scene/Scene.h"
 
+#include <array>
 #include <algorithm>
+#include <limits>
 
 namespace XCEngine {
 namespace Rendering {
@@ -15,42 +22,12 @@ namespace {
 
 constexpr uint32_t kDirectionalShadowMapDimension = 1024;
 constexpr float kMinShadowFocusDistance = 5.0f;
-constexpr float kMaxShadowFocusDistance = 25.0f;
-constexpr float kPerspectiveShadowFocusFactor = 0.25f;
+constexpr float kMaxShadowFocusDistance = 64.0f;
+constexpr float kPerspectiveShadowFocusFactor = 1.0f;
 constexpr float kOrthographicShadowFocusFactor = 2.0f;
-constexpr float kMinShadowHalfExtent = 10.0f;
-constexpr float kMaxShadowHalfExtent = 40.0f;
-constexpr float kPerspectiveShadowCoverageFactor = 0.20f;
-constexpr float kOrthographicShadowCoverageFactor = 2.0f;
-constexpr float kShadowNearClipPlane = 0.1f;
 constexpr float kMinShadowDepthRange = 20.0f;
-
-bool IsUsableDirectionalLight(const Components::LightComponent* light) {
-    return light != nullptr &&
-           light->IsEnabled() &&
-           light->GetGameObject() != nullptr &&
-           light->GetGameObject()->IsActiveInHierarchy() &&
-           light->GetLightType() == Components::LightType::Directional;
-}
-
-Components::LightComponent* FindMainDirectionalLight(const Components::Scene& scene) {
-    const std::vector<Components::LightComponent*> lights =
-        scene.FindObjectsOfType<Components::LightComponent>();
-
-    Components::LightComponent* mainDirectionalLight = nullptr;
-    for (Components::LightComponent* light : lights) {
-        if (!IsUsableDirectionalLight(light)) {
-            continue;
-        }
-
-        if (mainDirectionalLight == nullptr ||
-            light->GetIntensity() > mainDirectionalLight->GetIntensity()) {
-            mainDirectionalLight = light;
-        }
-    }
-
-    return mainDirectionalLight;
-}
+constexpr float kShadowBoundsPadding = 1.0f;
+constexpr float kMinShadowDepthPadding = 2.0f;
 
 bool ShouldPlanDirectionalShadowForCamera(
     const Components::CameraComponent& camera,
@@ -64,9 +41,68 @@ bool ShouldPlanDirectionalShadowForCamera(
     return true;
 }
 
+std::array<Math::Vector3, 8> BuildBoundsCorners(const Math::Bounds& bounds) {
+    const Math::Vector3 min = bounds.GetMin();
+    const Math::Vector3 max = bounds.GetMax();
+    return {
+        min,
+        Math::Vector3(max.x, min.y, min.z),
+        Math::Vector3(min.x, max.y, min.z),
+        Math::Vector3(min.x, min.y, max.z),
+        max,
+        Math::Vector3(min.x, max.y, max.z),
+        Math::Vector3(max.x, min.y, max.z),
+        Math::Vector3(max.x, max.y, min.z)
+    };
+}
+
+Math::Bounds TransformBoundsToWorldSpace(
+    const Math::Bounds& localBounds,
+    const Math::Matrix4x4& localToWorld,
+    std::array<Math::Vector3, 8>* outWorldCorners = nullptr) {
+    const std::array<Math::Vector3, 8> localCorners = BuildBoundsCorners(localBounds);
+    std::array<Math::Vector3, 8> worldCorners = {};
+    for (size_t index = 0; index < localCorners.size(); ++index) {
+        worldCorners[index] = localToWorld.MultiplyPoint(localCorners[index]);
+    }
+
+    Math::Bounds worldBounds(worldCorners[0], Math::Vector3::Zero());
+    for (size_t index = 1; index < worldCorners.size(); ++index) {
+        worldBounds.Encapsulate(worldCorners[index]);
+    }
+
+    if (outWorldCorners != nullptr) {
+        *outWorldCorners = worldCorners;
+    }
+
+    return worldBounds;
+}
+
+void ExpandLightSpaceBounds(
+    const Math::Matrix4x4& view,
+    const std::array<Math::Vector3, 8>& worldCorners,
+    float& minX,
+    float& maxX,
+    float& minY,
+    float& maxY,
+    float& minZ,
+    float& maxZ) {
+    for (const Math::Vector3& corner : worldCorners) {
+        const Math::Vector3 cornerLS = view.MultiplyPoint(corner);
+        minX = std::min(minX, cornerLS.x);
+        maxX = std::max(maxX, cornerLS.x);
+        minY = std::min(minY, cornerLS.y);
+        maxY = std::max(maxY, cornerLS.y);
+        minZ = std::min(minZ, cornerLS.z);
+        maxZ = std::max(maxZ, cornerLS.z);
+    }
+}
+
 DirectionalShadowRenderPlan BuildDirectionalShadowRenderPlan(
+    const Components::Scene& scene,
     const Components::CameraComponent& camera,
-    const Components::LightComponent& light) {
+    const Components::LightComponent& light,
+    float viewportAspect) {
     DirectionalShadowRenderPlan plan = {};
     if (!light.GetCastsShadows()) {
         return plan;
@@ -82,9 +118,16 @@ DirectionalShadowRenderPlan BuildDirectionalShadowRenderPlan(
     const Math::Vector3 viewForward = camera.transform().GetForward().SqrMagnitude() <= Math::EPSILON
         ? Math::Vector3::Forward()
         : camera.transform().GetForward().Normalized();
+    const Math::Vector3 viewRight = camera.transform().GetRight().SqrMagnitude() <= Math::EPSILON
+        ? Math::Vector3::Right()
+        : camera.transform().GetRight().Normalized();
+    const Math::Vector3 viewUp = camera.transform().GetUp().SqrMagnitude() <= Math::EPSILON
+        ? Math::Vector3::Up()
+        : camera.transform().GetUp().Normalized();
     const Math::Vector3 cameraPosition = camera.transform().GetPosition();
+    const float aspect = viewportAspect > Math::EPSILON ? viewportAspect : 1.0f;
 
-    const float focusDistance = camera.GetProjectionType() == Components::CameraProjectionType::Perspective
+    const float shadowDistance = camera.GetProjectionType() == Components::CameraProjectionType::Perspective
         ? std::clamp(
             camera.GetFarClipPlane() * kPerspectiveShadowFocusFactor,
             kMinShadowFocusDistance,
@@ -93,42 +136,151 @@ DirectionalShadowRenderPlan BuildDirectionalShadowRenderPlan(
             camera.GetOrthographicSize() * kOrthographicShadowFocusFactor,
             kMinShadowFocusDistance,
             kMaxShadowFocusDistance);
-    const Math::Vector3 focusPoint = cameraPosition + viewForward * focusDistance;
+    const float sliceNear = std::max(camera.GetNearClipPlane(), 0.1f);
+    const float sliceFar = std::max(sliceNear + 0.1f, shadowDistance);
 
-    const float shadowHalfExtent = camera.GetProjectionType() == Components::CameraProjectionType::Perspective
-        ? std::clamp(
-            camera.GetFarClipPlane() * kPerspectiveShadowCoverageFactor,
-            kMinShadowHalfExtent,
-            kMaxShadowHalfExtent)
-        : std::clamp(
-            camera.GetOrthographicSize() * kOrthographicShadowCoverageFactor,
-            kMinShadowHalfExtent,
-            kMaxShadowHalfExtent);
-    const float shadowDepthRange = std::max(shadowHalfExtent * 4.0f, kMinShadowDepthRange);
+    std::array<Math::Vector3, 8> frustumCorners = {};
+    if (camera.GetProjectionType() == Components::CameraProjectionType::Perspective) {
+        const float tanHalfFov = std::tan(camera.GetFieldOfView() * Math::DEG_TO_RAD * 0.5f);
+        const float nearHalfHeight = tanHalfFov * sliceNear;
+        const float nearHalfWidth = nearHalfHeight * aspect;
+        const float farHalfHeight = tanHalfFov * sliceFar;
+        const float farHalfWidth = farHalfHeight * aspect;
+
+        const Math::Vector3 nearCenter = cameraPosition + viewForward * sliceNear;
+        const Math::Vector3 farCenter = cameraPosition + viewForward * sliceFar;
+
+        frustumCorners[0] = nearCenter - viewRight * nearHalfWidth - viewUp * nearHalfHeight;
+        frustumCorners[1] = nearCenter + viewRight * nearHalfWidth - viewUp * nearHalfHeight;
+        frustumCorners[2] = nearCenter - viewRight * nearHalfWidth + viewUp * nearHalfHeight;
+        frustumCorners[3] = nearCenter + viewRight * nearHalfWidth + viewUp * nearHalfHeight;
+        frustumCorners[4] = farCenter - viewRight * farHalfWidth - viewUp * farHalfHeight;
+        frustumCorners[5] = farCenter + viewRight * farHalfWidth - viewUp * farHalfHeight;
+        frustumCorners[6] = farCenter - viewRight * farHalfWidth + viewUp * farHalfHeight;
+        frustumCorners[7] = farCenter + viewRight * farHalfWidth + viewUp * farHalfHeight;
+    } else {
+        const float orthoHalfHeight = camera.GetOrthographicSize();
+        const float orthoHalfWidth = orthoHalfHeight * aspect;
+        const Math::Vector3 nearCenter = cameraPosition + viewForward * sliceNear;
+        const Math::Vector3 farCenter = cameraPosition + viewForward * sliceFar;
+
+        frustumCorners[0] = nearCenter - viewRight * orthoHalfWidth - viewUp * orthoHalfHeight;
+        frustumCorners[1] = nearCenter + viewRight * orthoHalfWidth - viewUp * orthoHalfHeight;
+        frustumCorners[2] = nearCenter - viewRight * orthoHalfWidth + viewUp * orthoHalfHeight;
+        frustumCorners[3] = nearCenter + viewRight * orthoHalfWidth + viewUp * orthoHalfHeight;
+        frustumCorners[4] = farCenter - viewRight * orthoHalfWidth - viewUp * orthoHalfHeight;
+        frustumCorners[5] = farCenter + viewRight * orthoHalfWidth - viewUp * orthoHalfHeight;
+        frustumCorners[6] = farCenter - viewRight * orthoHalfWidth + viewUp * orthoHalfHeight;
+        frustumCorners[7] = farCenter + viewRight * orthoHalfWidth + viewUp * orthoHalfHeight;
+    }
+
+    Math::Vector3 focusPoint = Math::Vector3::Zero();
+    for (const Math::Vector3& corner : frustumCorners) {
+        focusPoint += corner;
+    }
+    focusPoint /= static_cast<float>(frustumCorners.size());
+
+    Math::Bounds frustumWorldBounds(frustumCorners[0], Math::Vector3::Zero());
+    for (size_t index = 1; index < frustumCorners.size(); ++index) {
+        frustumWorldBounds.Encapsulate(frustumCorners[index]);
+    }
+
+    const float shadowViewDistance = std::max(sliceFar, kMinShadowDepthRange * 0.5f);
     const Math::Vector3 shadowWorldPosition =
-        focusPoint - lightDirection * (shadowDepthRange * 0.5f);
+        focusPoint + lightDirection * shadowViewDistance;
 
     Math::Vector3 shadowUp = Math::Vector3::Up();
     if (std::abs(Math::Vector3::Dot(lightDirection, shadowUp)) > 0.98f) {
         shadowUp = Math::Vector3::Forward();
     }
 
-    const Math::Matrix4x4 view =
-        Math::Matrix4x4::LookAt(shadowWorldPosition, focusPoint, shadowUp);
+    const Math::Vector3 shadowForward = (focusPoint - shadowWorldPosition).SqrMagnitude() <= Math::EPSILON
+        ? (lightDirection * -1.0f)
+        : (focusPoint - shadowWorldPosition).Normalized();
+    const Math::Quaternion shadowRotation = Math::Quaternion::LookRotation(shadowForward, shadowUp);
+    const Math::Matrix4x4 view = Math::Matrix4x4::TRS(
+        shadowWorldPosition,
+        shadowRotation,
+        Math::Vector3::One()).Inverse();
+
+    float minX = std::numeric_limits<float>::max();
+    float maxX = std::numeric_limits<float>::lowest();
+    float minY = std::numeric_limits<float>::max();
+    float maxY = std::numeric_limits<float>::lowest();
+    float minZ = std::numeric_limits<float>::max();
+    float maxZ = std::numeric_limits<float>::lowest();
+    ExpandLightSpaceBounds(view, frustumCorners, minX, maxX, minY, maxY, minZ, maxZ);
+
+    const uint32_t cullingMask = camera.GetCullingMask();
+    const std::vector<Components::MeshFilterComponent*> meshFilters =
+        scene.FindObjectsOfType<Components::MeshFilterComponent>();
+    for (Components::MeshFilterComponent* meshFilter : meshFilters) {
+        if (meshFilter == nullptr ||
+            !meshFilter->IsEnabled() ||
+            meshFilter->GetGameObject() == nullptr) {
+            continue;
+        }
+
+        Components::GameObject* gameObject = meshFilter->GetGameObject();
+        if (!gameObject->IsActiveInHierarchy()) {
+            continue;
+        }
+
+        const uint32_t gameObjectLayerMask = 1u << gameObject->GetLayer();
+        if ((cullingMask & gameObjectLayerMask) == 0u) {
+            continue;
+        }
+
+        Components::MeshRendererComponent* meshRenderer =
+            gameObject->GetComponent<Components::MeshRendererComponent>();
+        if (meshRenderer == nullptr ||
+            !meshRenderer->IsEnabled() ||
+            (!meshRenderer->GetCastShadows() && !meshRenderer->GetReceiveShadows())) {
+            continue;
+        }
+
+        Resources::Mesh* mesh = meshFilter->GetMesh();
+        if (mesh == nullptr || !mesh->IsValid()) {
+            continue;
+        }
+
+        std::array<Math::Vector3, 8> worldCorners = {};
+        const Math::Bounds worldBounds = TransformBoundsToWorldSpace(
+            mesh->GetBounds(),
+            gameObject->GetTransform()->GetLocalToWorldMatrix(),
+            &worldCorners);
+        if (!frustumWorldBounds.Intersects(worldBounds)) {
+            continue;
+        }
+
+        ExpandLightSpaceBounds(view, worldCorners, minX, maxX, minY, maxY, minZ, maxZ);
+    }
+
+    minX -= kShadowBoundsPadding;
+    maxX += kShadowBoundsPadding;
+    minY -= kShadowBoundsPadding;
+    maxY += kShadowBoundsPadding;
+    minZ -= kMinShadowDepthPadding;
+    maxZ += kMinShadowDepthPadding;
+
+    const float shadowHalfExtent = std::max(
+        std::max(std::abs(minX), std::abs(maxX)),
+        std::max(std::abs(minY), std::abs(maxY)));
+    const float shadowDepthRange = std::max(maxZ - minZ, kMinShadowDepthRange);
     const Math::Matrix4x4 projection = Math::Matrix4x4::Orthographic(
-        -shadowHalfExtent,
-        shadowHalfExtent,
-        -shadowHalfExtent,
-        shadowHalfExtent,
-        kShadowNearClipPlane,
-        shadowDepthRange);
+        minX,
+        maxX,
+        minY,
+        maxY,
+        minZ,
+        maxZ);
 
     plan.enabled = true;
     plan.lightDirection = lightDirection;
     plan.focusPoint = focusPoint;
     plan.orthographicHalfExtent = shadowHalfExtent;
-    plan.nearClipPlane = kShadowNearClipPlane;
-    plan.farClipPlane = shadowDepthRange;
+    plan.nearClipPlane = minZ;
+    plan.farClipPlane = maxZ;
     plan.mapWidth = kDirectionalShadowMapDimension;
     plan.mapHeight = kDirectionalShadowMapDimension;
     plan.cameraData.view = view.Transpose();
@@ -195,11 +347,16 @@ std::vector<CameraRenderRequest> SceneRenderRequestPlanner::BuildRequests(
                 *camera,
                 renderedBaseCameraCount,
                 requests.size())) {
-            if (Components::LightComponent* mainDirectionalLight = FindMainDirectionalLight(scene);
+            if (Components::LightComponent* mainDirectionalLight =
+                    FindMainDirectionalLight(scene, camera->GetCullingMask());
                 mainDirectionalLight != nullptr &&
                 mainDirectionalLight->GetCastsShadows()) {
+                const float viewportAspect = surface.GetRenderAreaHeight() > 0
+                    ? static_cast<float>(surface.GetRenderAreaWidth()) /
+                        static_cast<float>(surface.GetRenderAreaHeight())
+                    : 1.0f;
                 request.directionalShadow =
-                    BuildDirectionalShadowRenderPlan(*camera, *mainDirectionalLight);
+                    BuildDirectionalShadowRenderPlan(scene, *camera, *mainDirectionalLight, viewportAspect);
                 if (request.directionalShadow.IsValid()) {
                     request.shadowCaster.clearFlags = RenderClearFlags::Depth;
                     request.shadowCaster.hasCameraDataOverride = true;

tests/Rendering/unit/test_render_scene_extractor.cpp

@@ -182,6 +182,101 @@ TEST(RenderSceneExtractor_Test, ExtractsBrightestDirectionalLightAsMainLight) {
     EXPECT_EQ(
         sceneData.lighting.mainDirectionalLight.direction,
         mainLightObject->GetTransform()->GetForward().Normalized() * -1.0f);
+
+    ASSERT_EQ(sceneData.lighting.additionalLightCount, 2u);
+    EXPECT_EQ(sceneData.lighting.additionalLights[0].type, RenderLightType::Directional);
+    EXPECT_FLOAT_EQ(sceneData.lighting.additionalLights[0].intensity, 0.5f);
+    EXPECT_EQ(sceneData.lighting.additionalLights[1].type, RenderLightType::Point);
+    EXPECT_FLOAT_EQ(sceneData.lighting.additionalLights[1].intensity, 10.0f);
+}
+
+TEST(RenderSceneExtractor_Test, ExtractsAdditionalLightsWithoutMainDirectionalAndFiltersByLightCullingMask) {
+    Scene scene("AdditionalLightsScene");
+
+    GameObject* cameraObject = scene.CreateGameObject("Camera");
+    auto* camera = cameraObject->AddComponent<CameraComponent>();
+    camera->SetPrimary(true);
+    camera->SetCullingMask(1u << 3);
+
+    GameObject* hiddenSpotObject = scene.CreateGameObject("HiddenSpot");
+    hiddenSpotObject->SetLayer(0);
+    auto* hiddenSpot = hiddenSpotObject->AddComponent<LightComponent>();
+    hiddenSpot->SetLightType(LightType::Spot);
+    hiddenSpot->SetIntensity(100.0f);
+    hiddenSpot->SetRange(50.0f);
+    hiddenSpot->SetSpotAngle(60.0f);
+    hiddenSpotObject->GetTransform()->SetLocalPosition(Vector3(0.0f, 0.0f, 1.0f));
+
+    GameObject* visiblePointObject = scene.CreateGameObject("VisiblePoint");
+    visiblePointObject->SetLayer(3);
+    auto* visiblePoint = visiblePointObject->AddComponent<LightComponent>();
+    visiblePoint->SetLightType(LightType::Point);
+    visiblePoint->SetColor(Color(0.9f, 0.2f, 0.1f, 1.0f));
+    visiblePoint->SetIntensity(4.0f);
+    visiblePoint->SetRange(12.0f);
+    visiblePointObject->GetTransform()->SetLocalPosition(Vector3(0.0f, 0.0f, 4.0f));
+
+    GameObject* visibleSpotObject = scene.CreateGameObject("VisibleSpot");
+    visibleSpotObject->SetLayer(3);
+    auto* visibleSpot = visibleSpotObject->AddComponent<LightComponent>();
+    visibleSpot->SetLightType(LightType::Spot);
+    visibleSpot->SetColor(Color(0.1f, 0.8f, 0.4f, 1.0f));
+    visibleSpot->SetIntensity(3.0f);
+    visibleSpot->SetRange(8.0f);
+    visibleSpot->SetSpotAngle(48.0f);
+    visibleSpotObject->GetTransform()->SetLocalPosition(Vector3(0.0f, 0.0f, 2.0f));
+    visibleSpotObject->GetTransform()->SetLocalRotation(
+        Quaternion::LookRotation(Vector3(0.0f, 0.0f, -1.0f)));
+
+    RenderSceneExtractor extractor;
+    const RenderSceneData sceneData = extractor.Extract(scene, nullptr, 800, 600);
+
+    EXPECT_FALSE(sceneData.lighting.HasMainDirectionalLight());
+    ASSERT_TRUE(sceneData.lighting.HasAdditionalLights());
+    ASSERT_EQ(sceneData.lighting.additionalLightCount, 2u);
+
+    const RenderAdditionalLightData& spotLight = sceneData.lighting.additionalLights[0];
+    EXPECT_EQ(spotLight.type, RenderLightType::Spot);
+    EXPECT_EQ(spotLight.color.g, 0.8f);
+    EXPECT_EQ(spotLight.position, Vector3(0.0f, 0.0f, 2.0f));
+    EXPECT_EQ(spotLight.direction, Vector3(0.0f, 0.0f, 1.0f));
+    EXPECT_FLOAT_EQ(spotLight.range, 8.0f);
+    EXPECT_FLOAT_EQ(spotLight.spotAngle, 48.0f);
+
+    const RenderAdditionalLightData& pointLightData = sceneData.lighting.additionalLights[1];
+    EXPECT_EQ(pointLightData.type, RenderLightType::Point);
+    EXPECT_EQ(pointLightData.color.r, 0.9f);
+    EXPECT_EQ(pointLightData.position, Vector3(0.0f, 0.0f, 4.0f));
+    EXPECT_FLOAT_EQ(pointLightData.range, 12.0f);
+    EXPECT_FLOAT_EQ(pointLightData.spotAngle, 0.0f);
+}
+
+TEST(RenderSceneExtractor_Test, LimitsAdditionalLightsToBoundedCountUsingStableTieBreakOrder) {
+    Scene scene("AdditionalLightCapScene");
+
+    GameObject* cameraObject = scene.CreateGameObject("Camera");
+    auto* camera = cameraObject->AddComponent<CameraComponent>();
+    camera->SetPrimary(true);
+
+    for (uint32_t index = 0; index < RenderLightingData::kMaxAdditionalLightCount + 2u; ++index) {
+        GameObject* lightObject = scene.CreateGameObject("PointLight" + std::to_string(index));
+        auto* light = lightObject->AddComponent<LightComponent>();
+        light->SetLightType(LightType::Point);
+        light->SetIntensity(1.0f);
+        light->SetRange(16.0f);
+        light->SetColor(Color(static_cast<float>(index), 0.0f, 0.0f, 1.0f));
+        lightObject->GetTransform()->SetLocalPosition(Vector3(0.0f, 0.0f, 4.0f));
+    }
+
+    RenderSceneExtractor extractor;
+    const RenderSceneData sceneData = extractor.Extract(scene, nullptr, 800, 600);
+
+    ASSERT_FALSE(sceneData.lighting.HasMainDirectionalLight());
+    ASSERT_EQ(sceneData.lighting.additionalLightCount, RenderLightingData::kMaxAdditionalLightCount);
+    for (uint32_t index = 0; index < RenderLightingData::kMaxAdditionalLightCount; ++index) {
+        EXPECT_EQ(sceneData.lighting.additionalLights[index].type, RenderLightType::Point);
+        EXPECT_FLOAT_EQ(sceneData.lighting.additionalLights[index].color.r, static_cast<float>(index));
+    }
 }
 
 TEST(RenderSceneExtractor_Test, FiltersVisibleItemsByCameraCullingMask) {