fix(glass): refine fluid response coverage (#641)

src/composables/__tests__/useGlassOpticalRenderer.spec.ts

@@ -4149,8 +4149,8 @@ describe('glass optical surface discovery', () => {
     expect(scene.children[0].material.fragmentShader).toContain('uniform float uReflectionStrength')
     expect(scene.children[0].material.fragmentShader).not.toContain('uWakeProgress')
     expect(scene.children[0].material.fragmentShader).not.toContain('temporalEnergy')
-    expect(scene.children[0].material.fragmentShader).toContain('const float dynamicRangeScale = 0.40')
+    expect(scene.children[0].material.fragmentShader).toContain('const float dynamicRangeScale = 0.52')
-    expect(scene.children[0].material.fragmentShader).toContain('const float dynamicRangeDensity = 6.250')
+    expect(scene.children[0].material.fragmentShader).toContain('const float dynamicRangeDensity = 3.698')
     expect(scene.children[0].material.fragmentShader).toContain('float pointerSpread = mix(26.0, 17.0, uQuality)')
     expect(scene.children[0].material.fragmentShader).not.toContain(
       'mix(mix(26.0, 17.0, uQuality), mix(12.0, 8.0, uQuality), frosted)',

src/rendering/glass/__tests__/glassFluidDynamics.spec.ts

@@ -1,5 +1,12 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest'
-import { createGlassFluidDynamics, GLASS_FLUID_FIELD_FRAGMENT_SHADER } from '@/rendering/glass/glassFluidDynamics'
+import {
+  createGlassFluidDynamics,
+  GLASS_FLUID_DYNAMIC_RANGE_DENSITY,
+  GLASS_FLUID_DYNAMIC_RANGE_SCALE,
+  GLASS_FLUID_FIELD_FRAGMENT_SHADER,
+  GLASS_FLUID_FRAGMENT_SURFACE_REFRACTION,
+  GLASS_FLUID_FRAGMENT_SURFACE_SHAPE,
+} from '@/rendering/glass/glassFluidDynamics'
 
 class FakeVector2 {
   constructor(
@@ -179,9 +186,26 @@ describe('glass fluid dynamics', () => {
 
   it('keeps the established field injection and decay equations', () => {
     expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).toContain('previousEnergy * uDecay')
-    expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).toContain('distanceSquared * 437.500')
+    expect(GLASS_FLUID_DYNAMIC_RANGE_SCALE).toBe(0.52)
-    expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).toContain('distanceSquared * 262.500')
+    expect(GLASS_FLUID_DYNAMIC_RANGE_DENSITY).toBeCloseTo(3.698, 3)
+    expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).toContain('distanceSquared * 258.876')
+    expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).toContain('distanceSquared * 155.325')
     expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).toContain('injection * 0.44')
     expect(GLASS_FLUID_FIELD_FRAGMENT_SHADER).not.toContain('uImpulse')
   })
+
+  it('narrows directional material coverage without replacing fluid refraction energy', () => {
+    expect(GLASS_FLUID_FRAGMENT_SURFACE_SHAPE).toContain(
+      'smoothstep(0.001, 0.012, length(uPointerVelocity))',
+    )
+    expect(GLASS_FLUID_FRAGMENT_SURFACE_SHAPE).toContain('directionalCoverageShape')
+    expect(GLASS_FLUID_FRAGMENT_SURFACE_SHAPE).toContain('pointerCoverageEnergy')
+    expect(GLASS_FLUID_FRAGMENT_SURFACE_SHAPE).toContain(
+      'pow(clamp(pointerCoverageShape * uMotion, 0.0, 1.0), 1.15)',
+    )
+    expect(GLASS_FLUID_FRAGMENT_SURFACE_REFRACTION).toContain(
+      'pointerDelta * pointerEnergy * pointerStrength',
+    )
+    expect(GLASS_FLUID_FRAGMENT_SURFACE_REFRACTION).not.toContain('pointerCoverageEnergy')
+  })
 })

src/rendering/glass/glassFluidDynamics.ts

@@ -44,7 +44,7 @@ export interface GlassFluidDynamics {
   step(): Texture
 }
 
-export const GLASS_FLUID_DYNAMIC_RANGE_SCALE = 0.4
+export const GLASS_FLUID_DYNAMIC_RANGE_SCALE = 0.52
 export const GLASS_FLUID_DYNAMIC_RANGE_DENSITY = 1 / GLASS_FLUID_DYNAMIC_RANGE_SCALE ** 2
 const GLASS_FLUID_BUFFER_SCALE = 0.25
 
@@ -216,8 +216,25 @@ export const GLASS_FLUID_FRAGMENT_SURFACE_SHAPE = `    vec2 pointerDelta = uPoin
       uDeformationStrength *
       uFlowStrength;
     float wakeEnergy = abs(wakeShape) * wakeEnvelope * uMotion;
+    // 覆盖能量比位移核更快收敛，避免高斯尾部把真实折射扩成整块色调覆盖。
+    float coverageDirectionality = max(
+      sharedDirectionality,
+      smoothstep(0.001, 0.012, length(uPointerVelocity))
+    );
+    float coverageWakeTravel =
+      0.08 * coverageDirectionality * mix(0.86, 1.18, uMotionExpansion);
+    float directionalCoverageShape = exp(-(
+      pow(pointerAlong + coverageWakeTravel * 0.45, 2.0) * pointerSpread * 0.55 +
+      pointerAcross * pointerAcross * pointerSpread * 2.8
+    ));
+    float pointerCoverageShape = mix(
+      radialPointerShape,
+      directionalCoverageShape,
+      coverageDirectionality
+    );
+    float pointerCoverageEnergy = pow(clamp(pointerCoverageShape * uMotion, 0.0, 1.0), 1.15);
     float liquidEnergy = clamp(max(
-      pointerEnergy,
+      pointerCoverageEnergy,
       max(min(1.0, trailEnergy) * 0.68, wakeEnergy * 0.82)
     ), 0.0, 1.0);`