EDIT: Forward-Z cascaded shadow map failed...

src/core/config.h

@@ -12,7 +12,7 @@ inline constexpr int kShadowCascadeCount = 4;
 // Maximum shadow distance for CSM in view-space units
 inline constexpr float kShadowCSMFar = 50.0f;
 // Shadow map resolution used for stabilization (texel snapping). Must match actual image size.
-inline constexpr float kShadowMapResolution = 2048.0f;
+inline constexpr float kShadowMapResolution = 4096.0f;
 // Extra XY expansion for cascade footprint (safety against FOV/aspect changes)
 inline constexpr float kShadowCascadeRadiusScale = 1.15f;
 // Additive XY margin in world units (light-space) beyond scaled radius

src/core/vk_sampler_manager.cpp

@@ -35,6 +35,9 @@ void SamplerManager::init(DeviceManager *deviceManager)
     sh.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER;
     sh.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER;
     sh.compareEnable = VK_FALSE; // manual PCF
+    // Depth shadow maps are single-level; keep base LOD only and avoid mip filtering.
+    sh.mipmapMode = VK_SAMPLER_MIPMAP_MODE_NEAREST;
+    sh.maxLod = 0.0f;
     sh.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
     vkCreateSampler(_deviceManager->device(), &sh, nullptr, &_shadowLinearClamp);
 }

src/core/vk_types.h

@@ -76,7 +76,6 @@ struct GPUSceneData {
     glm::vec4 sunlightDirection; // w for sun power
     glm::vec4 sunlightColor;
 
-    // CSM data (unused by current shaders until wired)
     glm::mat4 lightViewProjCascades[4];
     glm::vec4 cascadeSplitsView;
 };

src/scene/vk_scene.cpp

@@ -122,7 +122,7 @@ void SceneManager::update_scene()
         glm::vec3 up    = glm::normalize(glm::cross(L, right));
 
         const float csmFar = kShadowCSMFar; // configurable shadow distance
-        const float lambda = 0.8f; // split weighting
+        const float lambda = 0.5f; // split weighting
         const int cascades = kShadowCascadeCount;
 
         float splits[4] = {0, 0, 0, 0};
@@ -213,7 +213,9 @@ void SceneManager::update_scene()
             float bottom = centerLS.y - radius;
             float top    = centerLS.y + radius;
 
-            mat4 projLight = orthoRH_ZO(left, rightE, bottom, top, nearLS, farLS);
+            mat4 projLight = orthoRH_ZO(-40.f, 40.f, -40.f, 40.f, nearLS, farLS);
+
+            // projLight[1][1] *= -1.0f;
             return projLight * viewLight;
         };