feat: multi-light system with per-light cubemap array shadows

Architecture:
- SceneUBO (448B): mat4 vp + numLights + numShadowLights + LightData[8] + shadowParams[4]
- LightData: vec4 posAndIntensity + vec4 colorAndRange (32B per light)
- Push constants (main): mat4 model only (64B) — all light data in UBO
- Push constants (shadow): model(64) + lightViewProj(64) + lightPos(16) + shadowParams(16) = 160B
- Shadow: cubemap array (24 layers = 4 lights × 6 faces), samplerCubeArray in shader
- Shadow passes: numShadowLights × 6 faces (2 lights = 12 passes)
- Fragment shader: loop over lights, calcPBR per light, shadow from corresponding cubemap layer

New OBJ files with verified CCW winding:
- pyramid.obj, diamond.obj, torus.obj, cone.obj, sphere.obj

Scene 'Chaos Architecture':
- 28 sphere pyramid (physics)
- 30 falling diamonds (physics)
- 8 floating torus rings (decorative)
- 4 pyramid decorations (static)
- 4 cone pillars (static)
- Central torus knot (floating)
- 2 dynamic point lights (warm + cool), both cast shadows
- Both lights orbit in chaotic circles

ImGui panel:
- Per-light intensity, range, RGB sliders
- Shadow bias, sample radius, far plane sliders

227 tests, all pass

src/CortexEngine.App/Program.cs

@@ -133,17 +133,29 @@ class Program
                 physicsWorld.Update((float)timing.DeltaTime);
                 physicsWorld.SyncTransforms(world);
 
-                // Move light in a chaotic circle
+                // Move lights in chaotic circles
-                var lightEntity = world.Lookup("MainLight");
+                var mainLight = world.Lookup("MainLight");
-                if ((ulong)lightEntity.Id != 0)
+                if ((ulong)mainLight.Id != 0)
                 {
                     var t = totalTime;
                     var lx = MathF.Sin(t * 0.7f) * 8f + MathF.Cos(t * 0.3f) * 3f;
                     var ly = 12f + MathF.Sin(t * 0.5f) * 5f;
                     var lz = MathF.Cos(t * 0.6f) * 8f + MathF.Sin(t * 0.4f) * 3f;
-                    var lt = lightEntity.Get<Transform>();
+                    var lt = mainLight.Get<Transform>();
                     lt.Position = new Vector3(lx, ly, lz);
-                    lightEntity.Set(lt);
+                    mainLight.Set(lt);
+                }
+
+                var secondLight = world.Lookup("SecondLight");
+                if ((ulong)secondLight.Id != 0)
+                {
+                    var t = totalTime + MathF.PI;
+                    var lx = MathF.Cos(t * 0.5f) * 10f + MathF.Sin(t * 0.2f) * 4f;
+                    var ly = 8f + MathF.Cos(t * 0.4f) * 4f;
+                    var lz = MathF.Sin(t * 0.6f) * 10f + MathF.Cos(t * 0.3f) * 3f;
+                    var lt = secondLight.Get<Transform>();
+                    lt.Position = new Vector3(lx, ly, lz);
+                    secondLight.Set(lt);
                 }
 
                 var processed = queue.ProcessPending();
@@ -179,59 +191,60 @@ class Program
                     ImGui.End();
 
                     // Shadow parameters panel
-                    ImGui.Begin("Shadow Parameters");
+                    ImGui.Begin("Shadow & Light Parameters");
 
-                    var lightEntity2 = world.Lookup("MainLight");
+                    // Main light controls
-                    if ((ulong)lightEntity2.Id != 0)
+                    var mainLight2 = world.Lookup("MainLight");
+                    if ((ulong)mainLight2.Id != 0)
                     {
-                        var lightComp = lightEntity2.Get<Light>();
+                        var lc1 = mainLight2.Get<Light>();
-                        var intensity = lightComp.Intensity;
+                        var i1 = lc1.Intensity; var r1 = lc1.Range;
-                        var range = lightComp.Range;
+                        var cr1 = lc1.Color.X; var cg1 = lc1.Color.Y; var cb1 = lc1.Color.Z;
-                        var colorR = lightComp.Color.X;
+                        ImGui.Text("Main Light (warm)");
-                        var colorG = lightComp.Color.Y;
+                        ImGui.SliderFloat("1 Intensity", ref i1, 0.0f, 50.0f, "%.1f");
-                        var colorB = lightComp.Color.Z;
+                        ImGui.SliderFloat("1 Range", ref r1, 5.0f, 100.0f, "%.1f");
-
+                        ImGui.SliderFloat("1 R", ref cr1, 0.0f, 1.0f, "%.2f");
-                        ImGui.SliderFloat("Light Intensity", ref intensity, 0.0f, 100.0f, "%.1f");
+                        ImGui.SliderFloat("1 G", ref cg1, 0.0f, 1.0f, "%.2f");
-                        ImGui.SliderFloat("Light Range", ref range, 5.0f, 100.0f, "%.1f");
+                        ImGui.SliderFloat("1 B", ref cb1, 0.0f, 1.0f, "%.2f");
-                        ImGui.SliderFloat("Light R", ref colorR, 0.0f, 1.0f, "%.2f");
+                        lc1.Intensity = i1; lc1.Range = r1;
-                        ImGui.SliderFloat("Light G", ref colorG, 0.0f, 1.0f, "%.2f");
+                        lc1.Color = new Vector3(cr1, cg1, cb1);
-                        ImGui.SliderFloat("Light B", ref colorB, 0.0f, 1.0f, "%.2f");
+                        mainLight2.Set(lc1);
-                        ImGui.Separator();
-
-                        lightComp.Intensity = intensity;
-                        lightComp.Range = range;
-                        lightComp.Color = new Vector3(colorR, colorG, colorB);
-                        lightEntity2.Set(lightComp);
                     }
 
+                    ImGui.Separator();
+
+                    // Second light controls
+                    var secondLight2 = world.Lookup("SecondLight");
+                    if ((ulong)secondLight2.Id != 0)
+                    {
+                        var lc2 = secondLight2.Get<Light>();
+                        var i2 = lc2.Intensity; var r2 = lc2.Range;
+                        var cr2 = lc2.Color.X; var cg2 = lc2.Color.Y; var cb2 = lc2.Color.Z;
+                        ImGui.Text("Second Light (cool)");
+                        ImGui.SliderFloat("2 Intensity", ref i2, 0.0f, 50.0f, "%.1f");
+                        ImGui.SliderFloat("2 Range", ref r2, 5.0f, 100.0f, "%.1f");
+                        ImGui.SliderFloat("2 R", ref cr2, 0.0f, 1.0f, "%.2f");
+                        ImGui.SliderFloat("2 G", ref cg2, 0.0f, 1.0f, "%.2f");
+                        ImGui.SliderFloat("2 B", ref cb2, 0.0f, 1.0f, "%.2f");
+                        lc2.Intensity = i2; lc2.Range = r2;
+                        lc2.Color = new Vector3(cr2, cg2, cb2);
+                        secondLight2.Set(lc2);
+                    }
+
+                    ImGui.Separator();
+
                     var bias = vkRenderer.ShadowBias;
                     var sampleRadius = vkRenderer.ShadowSampleRadius;
                     var farPlane = vkRenderer.ShadowFarPlane;
 
-                    ImGui.SliderFloat("Shadow Bias", ref bias, 0.001f, 0.5f, "%.4f");
+                    ImGui.SliderFloat("Shadow Bias", ref bias, 0.0001f, 0.1f, "%.4f");
                     ImGui.SliderFloat("Sample Radius", ref sampleRadius, 0.001f, 0.1f, "%.4f");
                     ImGui.SliderFloat("Far Plane", ref farPlane, 10.0f, 120.0f, "%.1f");
-                    ImGui.Separator();
 
                     vkRenderer.ShadowBias = bias;
                     vkRenderer.ShadowSampleRadius = sampleRadius;
                     vkRenderer.ShadowFarPlane = farPlane;
 
-                    ImGui.Text($"Current: bias={bias:F4} radius={sampleRadius:F4} far={farPlane:F1}");
-
-                    if (ImGui.Button("Copy Parameters to Clipboard"))
-                    {
-                        var paramsText = $"bias={bias:F4}\nsampleRadius={sampleRadius:F4}\nfarPlane={farPlane:F1}\nshadowMapSize=2048";
-                        var lightEntity3 = world.Lookup("MainLight");
-                        if ((ulong)lightEntity3.Id != 0)
-                        {
-                            var lc = lightEntity3.Get<Light>();
-                            paramsText += $"\nlightIntensity={lc.Intensity:F1}\nlightRange={lc.Range:F1}\nlightColor=({lc.Color.X:F2},{lc.Color.Y:F2},{lc.Color.Z:F2})";
-                        }
-                        ImGui.SetClipboardText(paramsText);
-                        Console.WriteLine("[App] Parameters copied to clipboard:\n" + paramsText);
-                    }
-
                     ImGui.End();
 
                     renderer.EndImGuiFrame();
@@ -355,11 +368,15 @@ class Program
                 .Set(coneMesh);
         }
 
-        // Light
+        // Lights
         world.Entity("MainLight")
             .Set(new Transform(new Vector3(0, 20, 0), Quaternion.Identity, Vector3.One))
             .Set(Light.Point(new Vector3(0, 20, 0), new Vector3(1.0f, 0.95f, 0.85f), intensity: 15.0f, range: 60.0f));
 
+        world.Entity("SecondLight")
+            .Set(new Transform(new Vector3(-12, 10, 8), Quaternion.Identity, Vector3.One))
+            .Set(Light.Point(new Vector3(-12, 10, 8), new Vector3(0.3f, 0.6f, 1.0f), intensity: 10.0f, range: 40.0f));
+
         var entityCount = 0;
         world.Each((Entity e, ref Transform _) => entityCount++);
         Console.WriteLine($"[Scene] {entityCount} entities: sphere pyramid + diamond rain + 8 torus rings + 4 pyramids + 4 cones + floor + grid + light");

src/Engine.Graphics.Vulkan/Shaders/shadow.frag

@@ -5,9 +5,8 @@ layout(location = 0) out float outDepth;
 
 layout(push_constant) uniform PC {
     mat4 model;
-    vec4 lightPos;
-    vec4 lightColor;
     mat4 lightViewProj;
+    vec4 lightPos;
     vec4 shadowParams;
 } pc;
 

src/Engine.Graphics.Vulkan/Shaders/shadow.vert

@@ -4,9 +4,8 @@ layout(location = 0) in vec3 inPosition;
 
 layout(push_constant) uniform PC {
     mat4 model;
-    vec4 lightPos;
-    vec4 lightColor;
     mat4 lightViewProj;
+    vec4 lightPos;
     vec4 shadowParams;
 } pc;
 

src/Engine.Graphics.Vulkan/Shaders/triangle.frag

@@ -6,19 +6,21 @@ layout(location = 2) in vec3 fragAlbedo;
 
 layout(location = 0) out vec4 outColor;
 
-layout(set = 0, binding = 0) uniform CameraUBO {
+struct LightData {
-    mat4 vp;
+    vec4 posAndIntensity;
+    vec4 colorAndRange;
 };
 
-layout(set = 0, binding = 1) uniform samplerCube shadowCube;
+layout(set = 0, binding = 0) uniform SceneUBO {
+    mat4 vp;
+    int numLights;
+    int numShadowLights;
+    vec2 padding;
+    LightData lights[8];
+    vec4 shadowParams[4];
+} scene;
 
-layout(push_constant) uniform PC {
+layout(set = 0, binding = 1) uniform samplerCubeArray shadowArray;
-    mat4 model;
-    vec4 lightPos;
-    vec4 lightColor;
-    mat4 lightViewProj;
-    vec4 shadowParams;
-} pc;
 
 const vec3 AMBIENT = vec3(0.01, 0.01, 0.02);
 const float PI = 3.14159265359;
@@ -92,11 +94,11 @@ mat3 buildTangentBasis(vec3 dir)
     return mat3(tangent, bitangent, dir);
 }
 
-float calcShadow(vec3 worldPos, vec3 lightPos, vec3 N, vec3 L)
+float calcShadow(vec3 worldPos, vec3 lightPos, vec3 N, vec3 L, int lightIndex)
 {
-    float bias = pc.shadowParams.x;
+    float bias = scene.shadowParams[lightIndex].x;
-    float sampleRadius = pc.shadowParams.y;
+    float sampleRadius = scene.shadowParams[lightIndex].y;
-    float farPlane = pc.shadowParams.z;
+    float farPlane = scene.shadowParams[lightIndex].z;
 
     vec3 dir = worldPos - lightPos;
     float dist = length(dir);
@@ -112,7 +114,7 @@ float calcShadow(vec3 worldPos, vec3 lightPos, vec3 N, vec3 L)
     for (int i = 0; i < 16; i++)
     {
         vec3 sampleDir = normalize(dirNorm + basis * (POISSON_DISK[i] * radius));
-        float sampleDepth = texture(shadowCube, sampleDir).r;
+        float sampleDepth = texture(shadowArray, vec4(sampleDir, float(lightIndex))).r;
         float sampleMapped = sampleDepth * farPlane;
         shadow += (dist - slopeBias < sampleMapped) ? 1.0 : 0.0;
     }
@@ -121,28 +123,8 @@ float calcShadow(vec3 worldPos, vec3 lightPos, vec3 N, vec3 L)
     return shadow;
 }
 
-void main()
+vec3 calcPBR(vec3 N, vec3 V, vec3 L, vec3 radiance, vec3 albedo, float roughness, float metallic)
 {
-    vec3 N = normalize(fragNormal);
-    vec3 V = normalize(-fragWorldPos);
-    vec3 albedo = fragAlbedo;
-    float roughness = 0.5;
-    float metallic = 0.1;
-
-    vec3 lightPos = pc.lightPos.xyz;
-    float lightIntensity = pc.lightPos.w;
-    vec3 lightColor = pc.lightColor.xyz;
-    float lightRange = pc.lightColor.w;
-
-    vec3 toLight = lightPos - fragWorldPos;
-    float dist = length(toLight);
-    vec3 L = toLight / max(dist, 0.001);
-
-    float attenuation = pow(clamp(1.0 - dist / max(lightRange, 0.001), 0.0, 1.0), 2.0);
-    vec3 radiance = lightColor * lightIntensity * attenuation;
-
-    float shadow = calcShadow(fragWorldPos, lightPos, N, L);
-
     vec3 H = normalize(V + L);
     vec3 F0 = mix(vec3(0.04), albedo, metallic);
 
@@ -158,9 +140,41 @@ void main()
     vec3 kD = (vec3(1.0) - kS) * (1.0 - metallic);
 
     float NdotL = max(dot(N, L), 0.0);
-    vec3 lighting = (kD * albedo / PI + specular) * radiance * NdotL * shadow;
+    return (kD * albedo / PI + specular) * radiance * NdotL;
+}
 
-    vec3 color = AMBIENT * albedo + lighting;
+void main()
+{
+    vec3 N = normalize(fragNormal);
+    vec3 V = normalize(-fragWorldPos);
+    vec3 albedo = fragAlbedo;
+    float roughness = 0.5;
+    float metallic = 0.1;
+
+    vec3 color = AMBIENT * albedo;
+
+    for (int i = 0; i < scene.numLights; i++)
+    {
+        vec3 lightPos = scene.lights[i].posAndIntensity.xyz;
+        float lightIntensity = scene.lights[i].posAndIntensity.w;
+        vec3 lightColor = scene.lights[i].colorAndRange.xyz;
+        float lightRange = scene.lights[i].colorAndRange.w;
+
+        vec3 toLight = lightPos - fragWorldPos;
+        float dist = length(toLight);
+        vec3 L = toLight / max(dist, 0.001);
+
+        float attenuation = pow(clamp(1.0 - dist / max(lightRange, 0.001), 0.0, 1.0), 2.0);
+        vec3 radiance = lightColor * lightIntensity * attenuation;
+
+        float shadow = 1.0;
+        if (i < scene.numShadowLights)
+        {
+            shadow = calcShadow(fragWorldPos, lightPos, N, L, i);
+        }
+
+        color += calcPBR(N, V, L, radiance, albedo, roughness, metallic) * shadow;
+    }
 
     color = acesTonemap(color);
     color = pow(color, vec3(1.0 / 2.2));

src/Engine.Graphics.Vulkan/Shaders/triangle.vert

@@ -8,21 +8,27 @@ layout(location = 0) out vec3 fragWorldPos;
 layout(location = 1) out vec3 fragNormal;
 layout(location = 2) out vec3 fragAlbedo;
 
-layout(set = 0, binding = 0) uniform CameraUBO {
+struct LightData {
-    mat4 vp;
+    vec4 posAndIntensity;   // xyz = position, w = intensity
+    vec4 colorAndRange;     // xyz = color, w = range
 };
 
+layout(set = 0, binding = 0) uniform SceneUBO {
+    mat4 vp;
+    int numLights;
+    int numShadowLights;
+    vec2 padding;
+    LightData lights[8];
+    vec4 shadowParams[4];   // x=bias, y=sampleRadius, z=farPlane, w=unused
+} scene;
+
 layout(push_constant) uniform PC {
     mat4 model;
-    vec4 lightPos;
-    vec4 lightColor;
-    mat4 lightViewProj;
-    vec4 shadowParams;
 } pc;
 
 void main() {
     vec4 worldPos = pc.model * vec4(inPosition, 1.0);
-    gl_Position = vp * worldPos;
+    gl_Position = scene.vp * worldPos;
     fragWorldPos = worldPos.xyz;
     fragNormal = mat3(pc.model) * inNormal;
     fragAlbedo = inColor;

src/Engine.Graphics.Vulkan/VulkanFrameResources.cs

@@ -5,7 +5,7 @@ namespace Engine.Graphics.Vulkan;
 internal sealed unsafe class VulkanFrameResources : IDisposable
 {
     public const int MaxFramesInFlight = 2;
-    public const ulong UboSize = 64;
+    public const ulong UboSize = 448;
 
     public VkCommandPool CommandPool;
     public VkCommandBuffer[] CommandBuffers = new VkCommandBuffer[MaxFramesInFlight];

src/Engine.Graphics.Vulkan/VulkanPipeline.cs

@@ -154,7 +154,7 @@ internal sealed unsafe class VulkanPipeline : IDisposable
             {
                 stageFlags = VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment,
                 offset = 0,
-                size = 176,
+                size = 64,
             };
 
             var descLayout = DescriptorSetLayout;

src/Engine.Graphics.Vulkan/VulkanRenderer.cs

@@ -47,7 +47,7 @@ public sealed unsafe class VulkanRenderer : IRenderer, Engine.Graphics.IScreensh
         _shadowMap = new VulkanShadowMap(ctx.Device, ctx, _pipeline.DescriptorSetLayout);
 
         for (int i = 0; i < VulkanFrameResources.MaxFramesInFlight; i++)
-            _frameResources.UpdateShadowDescriptor(i, _shadowMap.ShadowSampler, _shadowMap.CubeColorView);
+            _frameResources.UpdateShadowDescriptor(i, _shadowMap.ShadowSampler, _shadowMap.CubeArrayColorView);
 
         _imGui = new VulkanImGui(ctx, _frameResources.CommandPool, swapchain.Format, swapchain.DepthFormat);
     }
@@ -87,40 +87,56 @@ public sealed unsafe class VulkanRenderer : IRenderer, Engine.Graphics.IScreensh
             vp = Matrix4x4.CreateLookAt(new Vector3(0, 0, -6), Vector3.Zero, Vector3.UnitY) * proj;
         }
 
-        // Collect point light from ECS — prefer light attached to a moving entity
+        // Collect all point lights from ECS
-        var lightPos = new Vector4(0, 5, 0, 0);
+        var lights = new List<(Vector3 pos, float intensity, Vector3 color, float range)>();
-        var lightColor = new Vector4(1, 1, 1, 0);
         world.Each((Entity e, ref Light l, ref Transform lt) =>
         {
-            if (l.IsPoint && lightPos.W == 0)
+            if (l.IsPoint)
-            {
+                lights.Add((lt.Position, l.Intensity, l.Color, l.Range));
-                lightPos = new Vector4(lt.Position, l.Intensity);
-                lightColor = new Vector4(l.Color, l.Range);
-            }
         });
-        if (lightPos.W == 0)
+        if (lights.Count == 0)
         {
             world.Each((Entity e, ref Light l) =>
             {
-                if (l.IsPoint && lightPos.W == 0)
+                if (l.IsPoint)
-                {
+                    lights.Add((l.Position, l.Intensity, l.Color, l.Range));
-                    lightPos = new Vector4(l.Position, l.Intensity);
-                    lightColor = new Vector4(l.Color, l.Range);
-                }
             });
         }
 
-        // Pack UBO: just mat4 vp (64 bytes)
+        int numLights = Math.Min(lights.Count, 8);
-        var uboData = stackalloc byte[64];
+        int numShadowLights = Math.Min(numLights, VulkanShadowMap.MaxShadowLights);
+
+        // Pack SceneUBO: mat4 vp(64) + int numLights(4) + int numShadowLights(4) + vec2 pad(8) + LightData[8](256) + vec4 shadowParams[4](64) = 400B → pad to 448
+        var uboData = stackalloc byte[448];
         var vpCopy = vp;
         System.Buffer.MemoryCopy(&vpCopy, uboData, 64, 64);
+        *(int*)(uboData + 64) = numLights;
+        *(int*)(uboData + 68) = numShadowLights;
 
-        // Compute light view-projection matrix for shadow mapping
+        for (int i = 0; i < numLights; i++)
-        var lightPosVec = new Vector3(lightPos.X, lightPos.Y, lightPos.Z);
+        {
-        var lightView = Matrix4x4.CreateLookAt(lightPosVec, Vector3.Zero, Vector3.UnitY);
+            var lp = new Vector4(lights[i].pos, lights[i].intensity);
-        var lightProj = Matrix4x4.CreatePerspectiveFieldOfView(MathF.PI / 3f, 1.0f, 0.1f, 60f);
+            var lc = new Vector4(lights[i].color, lights[i].range);
-        lightProj.M22 *= -1;
+            var lightOffset = 80 + i * 32;
-        var lightViewProj = lightView * lightProj;
+            System.Buffer.MemoryCopy(&lp, uboData + lightOffset, 16, 16);
+            System.Buffer.MemoryCopy(&lc, uboData + lightOffset + 16, 16, 16);
+        }
+
+        // Shadow params per shadow light
+        for (int i = 0; i < numShadowLights; i++)
+        {
+            var sp = new Vector4(ShadowBias, ShadowSampleRadius, ShadowFarPlane, 0);
+            System.Buffer.MemoryCopy(&sp, uboData + 336 + i * 16, 16, 16);
+        }
+
+        // Compute light view-proj for each shadow light
+        var lightViewProjs = new Matrix4x4[numShadowLights];
+        for (int i = 0; i < numShadowLights; i++)
+        {
+            var lightView = Matrix4x4.CreateLookAt(lights[i].pos, Vector3.Zero, Vector3.UnitY);
+            var lightProj = Matrix4x4.CreatePerspectiveFieldOfView(MathF.PI / 2f, 1.0f, 0.1f, ShadowFarPlane);
+            lightViewProjs[i] = lightView * lightProj;
+        }
 
         var drawCalls = new List<(VkBuffer vertexBuf, VkBuffer indexBuf, uint indexCount, Matrix4x4 model, bool castShadow)>();
 
@@ -142,10 +158,10 @@ public sealed unsafe class VulkanRenderer : IRenderer, Engine.Graphics.IScreensh
             drawCalls.Add((entry.vb.Buffer, entry.ib.Buffer, entry.indexCount, t.GetMatrix(), castShadow));
         });
 
-        Render(vp, drawCalls, uboData, lightPos, lightColor, lightViewProj);
+        Render(vp, drawCalls, uboData, lights, lightViewProjs, numShadowLights);
     }
 
-    private void Render(Matrix4x4 vp, List<(VkBuffer vertexBuf, VkBuffer indexBuf, uint indexCount, Matrix4x4 model, bool castShadow)> drawCalls, byte* uboData, Vector4 lightPos, Vector4 lightColor, Matrix4x4 lightViewProj)
+    private void Render(Matrix4x4 vp, List<(VkBuffer vertexBuf, VkBuffer indexBuf, uint indexCount, Matrix4x4 model, bool castShadow)> drawCalls, byte* uboData, List<(Vector3 pos, float intensity, Vector3 color, float range)> lights, Matrix4x4[] lightViewProjs, int numShadowLights)
     {
         _frameResources.WaitFrame(_frameIndex);
 
@@ -157,7 +173,7 @@ public sealed unsafe class VulkanRenderer : IRenderer, Engine.Graphics.IScreensh
         {
             _swapchain.Recreate(_ctx.SurfaceExtent.Width == 0 ? 1280 : (int)_ctx.SurfaceExtent.Width,
                                 _ctx.SurfaceExtent.Height == 0 ? 720 : (int)_ctx.SurfaceExtent.Height);
-            Render(vp, drawCalls, uboData, lightPos, lightColor, lightViewProj);
+            Render(vp, drawCalls, uboData, lights, lightViewProjs, numShadowLights);
             return;
         }
 
@@ -178,122 +194,123 @@ public sealed unsafe class VulkanRenderer : IRenderer, Engine.Graphics.IScreensh
         };
         Vk.vkBeginCommandBuffer(cmd, &beginInfo);
 
-        // === SHADOW CUBEMAP PASSES (6 faces) ===
+        // === SHADOW CUBEMAP ARRAY PASSES (numShadowLights × 6 faces) ===
-        // Transition color cube: Undefined → ColorAttachmentOptimal
+        int totalLayers = numShadowLights * 6;
         TransitionImageLayout(cmd, _shadowMap.ColorImage,
             VkImageLayout.Undefined, VkImageLayout.ColorAttachmentOptimal,
-            0, 0, 0x400, 0x100, 6);
+            0, 0, 0x400, 0x100, (uint)totalLayers);
-        // Transition depth cube: Undefined → DepthStencilAttachmentOptimal
         TransitionImageLayoutDepth(cmd, _shadowMap.DepthImage,
             VkImageLayout.Undefined, VkImageLayout.DepthStencilAttachmentOptimal,
-            0, 0, 0x100, 0x200, 6);
+            0, 0, 0x100, 0x200, (uint)totalLayers);
 
-        var lightPosVec = new Vector3(lightPos.X, lightPos.Y, lightPos.Z);
+        for (int lightIdx = 0; lightIdx < numShadowLights; lightIdx++)
-
-        for (int face = 0; face < 6; face++)
         {
-            var (faceView, faceProj) = VulkanShadowMap.GetFaceViewProj(lightPosVec, face);
+            var lightPosVec = lights[lightIdx].pos;
-            var faceViewProj = faceView * faceProj;
 
-            var colorClear = new VkClearValue
+            for (int face = 0; face < 6; face++)
             {
-                Color = new VkClearColorValue { Float0 = 1.0f, Float1 = 0, Float2 = 0, Float3 = 0 },
+                var (faceView, faceProj) = VulkanShadowMap.GetFaceViewProj(lightPosVec, face);
-            };
+                var faceViewProj = faceView * faceProj;
+                int faceIndex = lightIdx * 6 + face;
 
-            var shadowColorAttachment = new VkRenderingAttachmentInfo
+                var colorClear = new VkClearValue
-            {
+                {
-                sType = VkStructureType.RenderingAttachmentInfo,
+                    Color = new VkClearColorValue { Float0 = 1.0f, Float1 = 0, Float2 = 0, Float3 = 0 },
-                imageView = _shadowMap.FaceColorViews[face],
+                };
-                imageLayout = VkImageLayout.ColorAttachmentOptimal,
-                loadOp = VkAttachmentLoadOp.Clear,
-                storeOp = VkAttachmentStoreOp.Store,
-                clearValue = colorClear,
-            };
 
-            var shadowDepthClear = new VkClearValue
+                var shadowColorAttachment = new VkRenderingAttachmentInfo
-            {
+                {
-                DepthStencil = new VkClearDepthStencilValue { Depth = 1.0f, Stencil = 0 },
+                    sType = VkStructureType.RenderingAttachmentInfo,
-            };
+                    imageView = _shadowMap.FaceColorViews[faceIndex],
+                    imageLayout = VkImageLayout.ColorAttachmentOptimal,
+                    loadOp = VkAttachmentLoadOp.Clear,
+                    storeOp = VkAttachmentStoreOp.Store,
+                    clearValue = colorClear,
+                };
 
-            var shadowDepthAttachment = new VkRenderingAttachmentInfo
+                var shadowDepthClear = new VkClearValue
-            {
+                {
-                sType = VkStructureType.RenderingAttachmentInfo,
+                    DepthStencil = new VkClearDepthStencilValue { Depth = 1.0f, Stencil = 0 },
-                imageView = _shadowMap.FaceDepthViews[face],
+                };
-                imageLayout = VkImageLayout.DepthStencilAttachmentOptimal,
-                loadOp = VkAttachmentLoadOp.Clear,
-                storeOp = VkAttachmentStoreOp.Store,
-                clearValue = shadowDepthClear,
-            };
 
-            var shadowRenderingInfo = new VkRenderingInfo
+                var shadowDepthAttachment = new VkRenderingAttachmentInfo
-            {
+                {
-                sType = VkStructureType.RenderingInfo,
+                    sType = VkStructureType.RenderingAttachmentInfo,
-                renderArea = new VkRect2D
+                    imageView = _shadowMap.FaceDepthViews[faceIndex],
+                    imageLayout = VkImageLayout.DepthStencilAttachmentOptimal,
+                    loadOp = VkAttachmentLoadOp.Clear,
+                    storeOp = VkAttachmentStoreOp.Store,
+                    clearValue = shadowDepthClear,
+                };
+
+                var shadowRenderingInfo = new VkRenderingInfo
+                {
+                    sType = VkStructureType.RenderingInfo,
+                    renderArea = new VkRect2D
+                    {
+                        Offset = new VkOffset2D { X = 0, Y = 0 },
+                        Extent = new VkExtent2D { Width = VulkanShadowMap.ShadowMapSize, Height = VulkanShadowMap.ShadowMapSize },
+                    },
+                    layerCount = 1,
+                    colorAttachmentCount = 1,
+                    pColorAttachments = &shadowColorAttachment,
+                    pDepthAttachment = &shadowDepthAttachment,
+                };
+
+                Vk.vkCmdBeginRendering(cmd, &shadowRenderingInfo);
+                Vk.vkCmdBindPipeline(cmd, VkPipelineBindPoint.Graphics, _shadowMap.Pipeline);
+
+                var shadowViewport = new VkViewport
+                {
+                    X = 0, Y = 0,
+                    Width = VulkanShadowMap.ShadowMapSize,
+                    Height = VulkanShadowMap.ShadowMapSize,
+                    MinDepth = 0, MaxDepth = 1,
+                };
+                Vk.vkCmdSetViewport(cmd, 0, 1, &shadowViewport);
+
+                var shadowScissor = new VkRect2D
                 {
                     Offset = new VkOffset2D { X = 0, Y = 0 },
                     Extent = new VkExtent2D { Width = VulkanShadowMap.ShadowMapSize, Height = VulkanShadowMap.ShadowMapSize },
-                },
+                };
-                layerCount = 1,
+                Vk.vkCmdSetScissor(cmd, 0, 1, &shadowScissor);
-                colorAttachmentCount = 1,
+                Vk.vkCmdSetDepthBias(cmd, 1.75f, 0.0f, 2.5f);
-                pColorAttachments = &shadowColorAttachment,
-                pDepthAttachment = &shadowDepthAttachment,
-            };
 
-            Vk.vkCmdBeginRendering(cmd, &shadowRenderingInfo);
+                var lpVec4 = new Vector4(lightPosVec, lights[lightIdx].intensity);
-
-            Vk.vkCmdBindPipeline(cmd, VkPipelineBindPoint.Graphics, _shadowMap.Pipeline);
-
-            var shadowViewport = new VkViewport
-            {
-                X = 0, Y = 0,
-                Width = VulkanShadowMap.ShadowMapSize,
-                Height = VulkanShadowMap.ShadowMapSize,
-                MinDepth = 0, MaxDepth = 1,
-            };
-            Vk.vkCmdSetViewport(cmd, 0, 1, &shadowViewport);
-
-            var shadowScissor = new VkRect2D
-            {
-                Offset = new VkOffset2D { X = 0, Y = 0 },
-                Extent = new VkExtent2D { Width = VulkanShadowMap.ShadowMapSize, Height = VulkanShadowMap.ShadowMapSize },
-            };
-            Vk.vkCmdSetScissor(cmd, 0, 1, &shadowScissor);
-
-            Vk.vkCmdSetDepthBias(cmd, 1.75f, 0.0f, 2.5f);
-
-            foreach (var dc in drawCalls)
-            {
-                if (!dc.castShadow) continue;
-
-                var vertexBuf = dc.vertexBuf;
-                ulong offset = 0;
-                Vk.vkCmdBindVertexBuffers(cmd, 0, 1, &vertexBuf, &offset);
-                Vk.vkCmdBindIndexBuffer(cmd, dc.indexBuf, 0, 1);
-
-                var pcData = stackalloc byte[176];
-                var modelCopy = dc.model;
-                System.Buffer.MemoryCopy(&modelCopy, pcData, 64, 64);
-                var lpCopy = lightPos;
-                System.Buffer.MemoryCopy(&lpCopy, pcData + 64, 16, 16);
-                var lcCopy = lightColor;
-                System.Buffer.MemoryCopy(&lcCopy, pcData + 80, 16, 16);
-                var lvpCopy = faceViewProj;
-                System.Buffer.MemoryCopy(&lvpCopy, pcData + 96, 64, 64);
                 var sp = new Vector4(ShadowBias, ShadowSampleRadius, ShadowFarPlane, 0);
-                System.Buffer.MemoryCopy(&sp, pcData + 160, 16, 16);
 
-                Vk.vkCmdPushConstants(cmd, _shadowMap.PipelineLayout, VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment, 0, 176, pcData);
+                foreach (var dc in drawCalls)
+                {
+                    if (!dc.castShadow) continue;
 
-                Vk.vkCmdDrawIndexed(cmd, dc.indexCount, 1, 0, 0, 0);
+                    var vertexBuf = dc.vertexBuf;
+                    ulong offset = 0;
+                    Vk.vkCmdBindVertexBuffers(cmd, 0, 1, &vertexBuf, &offset);
+                    Vk.vkCmdBindIndexBuffer(cmd, dc.indexBuf, 0, 1);
+
+                    // Pack shadow push constants: model(64) + lightViewProj(64) + lightPos(16) + shadowParams(16) = 160
+                    var pcData = stackalloc byte[160];
+                    var modelCopy = dc.model;
+                    System.Buffer.MemoryCopy(&modelCopy, pcData, 64, 64);
+                    var lvpCopy = faceViewProj;
+                    System.Buffer.MemoryCopy(&lvpCopy, pcData + 64, 64, 64);
+                    System.Buffer.MemoryCopy(&lpVec4, pcData + 128, 16, 16);
+                    System.Buffer.MemoryCopy(&sp, pcData + 144, 16, 16);
+
+                    Vk.vkCmdPushConstants(cmd, _shadowMap.PipelineLayout, VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment, 0, 160, pcData);
+
+                    Vk.vkCmdDrawIndexed(cmd, dc.indexCount, 1, 0, 0, 0);
+                }
+
+                Vk.vkCmdEndRendering(cmd);
             }
-
-            Vk.vkCmdEndRendering(cmd);
         }
 
-        // Transition shadow color cube: ColorAttachmentOptimal → ShaderReadOnlyOptimal
+        // Transition shadow color array: ColorAttachmentOptimal → ShaderReadOnlyOptimal
         TransitionImageLayout(cmd, _shadowMap.ColorImage,
             VkImageLayout.ColorAttachmentOptimal, VkImageLayout.ShaderReadOnlyOptimal,
-            0x400, 0x100, 0x8, 0x20, 6);
+            0x400, 0x100, 0x8, 0x20, (uint)totalLayers);
 
         // === MAIN PASS ===
         TransitionImageLayout(cmd, _swapchain.Images[imageIndex],
@@ -381,20 +398,9 @@ public sealed unsafe class VulkanRenderer : IRenderer, Engine.Graphics.IScreensh
             Vk.vkCmdBindVertexBuffers(cmd, 0, 1, &vertexBuf, &offset);
             Vk.vkCmdBindIndexBuffer(cmd, dc.indexBuf, 0, 1);
 
-            // Pack all push constants: model(64) + lightPos(16) + lightColor(16) + lightViewProj(64) = 160
+            // Main pass push constants: model only (64B)
-            var pcData = stackalloc byte[176];
+            var model = dc.model;
-            var modelCopy = dc.model;
+            Vk.vkCmdPushConstants(cmd, _pipeline.PipelineLayout, VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment, 0, 64, &model);
-            System.Buffer.MemoryCopy(&modelCopy, pcData, 64, 64);
-            var lpCopy = lightPos;
-            System.Buffer.MemoryCopy(&lpCopy, pcData + 64, 16, 16);
-            var lcCopy = lightColor;
-            System.Buffer.MemoryCopy(&lcCopy, pcData + 80, 16, 16);
-            var lvpCopy = lightViewProj;
-            System.Buffer.MemoryCopy(&lvpCopy, pcData + 96, 64, 64);
-            var sp = new Vector4(ShadowBias, ShadowSampleRadius, ShadowFarPlane, 0);
-            System.Buffer.MemoryCopy(&sp, pcData + 160, 16, 16);
-
-            Vk.vkCmdPushConstants(cmd, _pipeline.PipelineLayout, VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment, 0, 176, pcData);
 
             Vk.vkCmdDrawIndexed(cmd, dc.indexCount, 1, 0, 0, 0);
         }

src/Engine.Graphics.Vulkan/VulkanShadowMap.cs

@@ -5,17 +5,17 @@ namespace Engine.Graphics.Vulkan;
 
 internal sealed unsafe class VulkanShadowMap : IDisposable
 {
-    public const uint ShadowMapSize = 2048;
+    public const uint ShadowMapSize = 1024;
-    public const float FarPlane = 60.0f;
+    public const int MaxShadowLights = 4;
 
     public VkImage ColorImage;
     public VkDeviceMemory ColorImageMemory;
-    public VkImageView CubeColorView;
+    public VkImageView CubeArrayColorView;
-    public VkImageView[] FaceColorViews = new VkImageView[6];
+    public VkImageView[] FaceColorViews = new VkImageView[MaxShadowLights * 6];
 
     public VkImage DepthImage;
     public VkDeviceMemory DepthImageMemory;
-    public VkImageView[] FaceDepthViews = new VkImageView[6];
+    public VkImageView[] FaceDepthViews = new VkImageView[MaxShadowLights * 6];
 
     public VkSampler ShadowSampler;
     public VkPipeline Pipeline;
@@ -35,12 +35,14 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
         CreateShadowSampler();
         CreateShadowPipeline();
 
-        Console.WriteLine("[Vulkan] Shadow cubemap created (1024x1024x6, R32_SFLOAT + D32_SFLOAT)");
+        Console.WriteLine($"[Vulkan] Shadow cubemap array created ({ShadowMapSize}x{ShadowMapSize}x{MaxShadowLights*6} layers)");
     }
 
     private void CreateShadowImages()
     {
-        // Color cube (R32_SFLOAT) — stores linear distance
+        int totalLayers = MaxShadowLights * 6;
+
+        // Color cube array (R32_SFLOAT) — stores linear distance
         var colorInfo = new VkImageCreateInfo
         {
             sType = VkStructureType.ImageCreateInfo,
@@ -49,7 +51,7 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
             format = VkFormat.R32Sfloat,
             extent = new VkExtent3D { Width = ShadowMapSize, Height = ShadowMapSize, Depth = 1 },
             mipLevels = 1,
-            arrayLayers = 6,
+            arrayLayers = (uint)totalLayers,
             samples = VkSampleCountFlags.Count1,
             tiling = VkImageTiling.Optimal,
             usage = VkImageUsageFlags.ColorAttachment | VkImageUsageFlags.Sampled,
@@ -70,22 +72,22 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
         ColorImageMemory = colorMem;
         Vk.vkBindImageMemory(_device, ColorImage, ColorImageMemory, 0);
 
-        // Cube color view for sampling
+        // Cube array color view for sampling
-        var cubeColorViewInfo = new VkImageViewCreateInfo
+        var cubeArrayViewInfo = new VkImageViewCreateInfo
         {
             sType = VkStructureType.ImageViewCreateInfo,
             image = ColorImage,
-            viewType = VkImageViewType.TypeCube,
+            viewType = VkImageViewType.TypeCubeArray,
             format = VkFormat.R32Sfloat,
             components = new VkComponentMapping { R = VkComponentSwizzle.Identity, G = VkComponentSwizzle.Identity, B = VkComponentSwizzle.Identity, A = VkComponentSwizzle.Identity },
-            subresourceRange = new VkImageSubresourceRange { AspectMask = VkImageAspectFlags.Color, BaseMipLevel = 0, LevelCount = 1, BaseArrayLayer = 0, LayerCount = 6 },
+            subresourceRange = new VkImageSubresourceRange { AspectMask = VkImageAspectFlags.Color, BaseMipLevel = 0, LevelCount = 1, BaseArrayLayer = 0, LayerCount = (uint)totalLayers },
         };
-        var cubeCV = VkImageView.Null;
+        var cubeArrayView = VkImageView.Null;
-        Vk.vkCreateImageView(_device, &cubeColorViewInfo, 0, &cubeCV);
+        Vk.vkCreateImageView(_device, &cubeArrayViewInfo, 0, &cubeArrayView);
-        CubeColorView = cubeCV;
+        CubeArrayColorView = cubeArrayView;
 
-        // 6 face color views
+        // Face color views for rendering
-        for (int i = 0; i < 6; i++)
+        for (int i = 0; i < totalLayers; i++)
         {
             var faceViewInfo = new VkImageViewCreateInfo
             {
@@ -101,7 +103,7 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
             FaceColorViews[i] = fv;
         }
 
-        // Depth cube (D32_SFLOAT) — for depth testing during shadow render
+        // Depth cube array (D32_SFLOAT)
         var depthInfo = new VkImageCreateInfo
         {
             sType = VkStructureType.ImageCreateInfo,
@@ -110,7 +112,7 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
             format = VkFormat.D32Sfloat,
             extent = new VkExtent3D { Width = ShadowMapSize, Height = ShadowMapSize, Depth = 1 },
             mipLevels = 1,
-            arrayLayers = 6,
+            arrayLayers = (uint)totalLayers,
             samples = VkSampleCountFlags.Count1,
             tiling = VkImageTiling.Optimal,
             usage = VkImageUsageFlags.DepthStencilAttachment,
@@ -131,8 +133,8 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
         DepthImageMemory = depthMem;
         Vk.vkBindImageMemory(_device, DepthImage, DepthImageMemory, 0);
 
-        // 6 face depth views
+        // Face depth views
-        for (int i = 0; i < 6; i++)
+        for (int i = 0; i < totalLayers; i++)
         {
             var faceDepthViewInfo = new VkImageViewCreateInfo
             {
@@ -323,7 +325,7 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
                 pDynamicStates = dynamicStates,
             };
 
-            var pushConstantRange = new VkPushConstantRange { stageFlags = VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment, offset = 0, size = 176 };
+            var pushConstantRange = new VkPushConstantRange { stageFlags = VkShaderStageFlags.Vertex | VkShaderStageFlags.Fragment, offset = 0, size = 160 };
 
             var layoutInfo = new VkPipelineLayoutCreateInfo
             {
@@ -415,8 +417,8 @@ internal sealed unsafe class VulkanShadowMap : IDisposable
         if (PipelineLayout.Handle != 0) Vk.vkDestroyPipelineLayout(_device, PipelineLayout, 0);
         if (VertModule.Handle != 0) Vk.vkDestroyShaderModule(_device, VertModule, 0);
         if (ShadowSampler.Handle != 0) Vk.vkDestroySampler(_device, ShadowSampler, 0);
-        if (CubeColorView.Handle != 0) Vk.vkDestroyImageView(_device, CubeColorView, 0);
+        if (CubeArrayColorView.Handle != 0) Vk.vkDestroyImageView(_device, CubeArrayColorView, 0);
-        for (int i = 0; i < 6; i++)
+        for (int i = 0; i < MaxShadowLights * 6; i++)
         {
             if (FaceColorViews[i].Handle != 0) Vk.vkDestroyImageView(_device, FaceColorViews[i], 0);
             if (FaceDepthViews[i].Handle != 0) Vk.vkDestroyImageView(_device, FaceDepthViews[i], 0);