Support shadow fade

e2e/case/shadow-basic.ts

@@ -0,0 +1,56 @@
+/**
+ * @title Shadow basic
+ * @category Shadow
+ */
+import {
+  Animator,
+  Camera,
+  DirectLight,
+  GLTFResource,
+  MeshRenderer,
+  PBRMaterial,
+  PrimitiveMesh,
+  ShadowResolution,
+  ShadowType,
+  Vector3,
+  WebGLEngine
+} from "@galacean/engine";
+
+import { initScreenshot, updateForE2E } from "./.mockForE2E";
+
+WebGLEngine.create({ canvas: "canvas" }).then((engine) => {
+  engine.canvas.resizeByClientSize();
+  const scene = engine.sceneManager.activeScene;
+  const rootEntity = scene.createRootEntity();
+  scene.shadowResolution = ShadowResolution.Medium;
+  scene.shadowDistance = 5;
+  const cameraEntity = rootEntity.createChild("camera_node");
+  cameraEntity.transform.setPosition(0, 2, 3);
+  cameraEntity.transform.lookAt(new Vector3(0));
+  const camera = cameraEntity.addComponent(Camera);
+  const lightEntity = rootEntity.createChild("light_node");
+  const light = lightEntity.addComponent(DirectLight);
+  lightEntity.transform.setPosition(-10, 10, 10);
+  lightEntity.transform.lookAt(new Vector3(0, 0, 0));
+
+  light.shadowType = ShadowType.SoftHigh;
+
+  const planeEntity = rootEntity.createChild("plane_node");
+  const renderer = planeEntity.addComponent(MeshRenderer);
+  renderer.mesh = PrimitiveMesh.createPlane(engine, 10, 10);
+  const planeMaterial = new PBRMaterial(engine);
+  renderer.setMaterial(planeMaterial);
+
+  engine.resourceManager
+    .load<GLTFResource>("https://gw.alipayobjects.com/os/bmw-prod/5e3c1e4e-496e-45f8-8e05-f89f2bd5e4a4.glb")
+    .then((asset) => {
+      const { defaultSceneRoot } = asset;
+      rootEntity.addChild(defaultSceneRoot);
+
+      const animator = defaultSceneRoot.getComponent(Animator);
+      animator.play(asset.animations[0].name);
+
+      updateForE2E(engine, 500);
+      initScreenshot(engine, camera);
+    });
+});

e2e/config.ts

@@ -89,5 +89,12 @@ export const E2E_CONFIG = {
       caseFileName: "material-unlit",
       threshold: 0.2
     }
+  },
+  Shadow: {
+    basic: {
+      category: "Shadow",
+      caseFileName: "shadow-basic",
+      threshold: 0.2
+    }
   }
 };

package.json

@@ -68,5 +68,6 @@
       "eslint --fix",
       "git add"
     ]
-  }
-}
+  },
+  "repository": "[email protected]:galacean/runtime.git"
+}

packages/core/src/Scene.ts

@@ -42,6 +42,11 @@ export class Scene extends EngineObject {
   shadowFourCascadeSplits: Vector3 = new Vector3(1.0 / 15, 3.0 / 15.0, 7.0 / 15.0);
   /** Max Shadow distance. */
   shadowDistance: number = 50;
+  /**
+   * Last shadow fade distance in percentage, range [0,1].
+   * @remarks Value 0 is used for no shadow fade.
+   */
+  shadowFadeBorder: number = 0.1;
 
   /* @internal */
   _lightManager: LightManager = new LightManager();

packages/core/src/shaderlib/mobile_blinnphong_frag.glsl

@@ -13,7 +13,6 @@
         shadowAttenuation = 1.0;
         #ifdef SCENE_IS_CALCULATE_SHADOWS
             shadowAttenuation *= sampleShadowMap();
-            // int sunIndex = int(scene_ShadowInfo.z);
         #endif
 
     DirectLight directionalLight;

packages/core/src/shaderlib/pbr/direct_irradiance_frag_define.glsl

@@ -79,7 +79,6 @@ void addTotalDirectRadiance(Geometry geometry, Material material, inout Reflecte
         shadowAttenuation = 1.0;
         #ifdef SCENE_IS_CALCULATE_SHADOWS
             shadowAttenuation *= sampleShadowMap();
-            // int sunIndex = int(scene_ShadowInfo.z);
         #endif
 
         DirectLight directionalLight;

packages/core/src/shaderlib/shadow/ShadowFragmentDeclaration.glsl

@@ -9,8 +9,8 @@
         #include <ShadowCoord>
     #endif
 
-    // intensity, resolution, sunIndex
-    uniform vec3 scene_ShadowInfo;
+    // intensity, null, fadeScale, fadeBias
+    uniform vec4 scene_ShadowInfo;
     uniform vec4 scene_ShadowMapSize;
 
     #ifdef GRAPHICS_API_WEBGL2
@@ -73,6 +73,13 @@
         }
     #endif
 
+
+    float getShadowFade(vec3 positionWS){
+        vec3 camToPixel = positionWS - camera_Position;
+        float distanceCamToPixel2 = dot(camToPixel, camToPixel);
+        return saturate( distanceCamToPixel2 * scene_ShadowInfo.z + scene_ShadowInfo.w );
+    }
+
     float sampleShadowMap() {
         #if SCENE_SHADOW_CASCADED_COUNT == 1
             vec3 shadowCoord = v_shadowCoord;
@@ -93,7 +100,9 @@
         #if SCENE_SHADOW_TYPE == 3
             attenuation = sampleShadowMapFiltered9(scene_ShadowMap, shadowCoord, scene_ShadowMapSize);
         #endif
-            attenuation = mix(1.0, attenuation, scene_ShadowInfo.x);
+
+        float shadowFade = getShadowFade(v_pos);
+        attenuation = mix(1.0, mix(attenuation, 1.0, shadowFade), scene_ShadowInfo.x);
         }
         return attenuation;
     }