atdunbg
d3c3d0cdd9
掠射角下 GGX spec 分母 (4·NdotV·NdotL) 变小，HDR 值可达 8+； 阴影只把它乘 0.3，30% 的刺眼白仍比天空亮——观感即"影子发白"。 - spec 项按 shade 重映射（0.3→0，1.0→1）：光源被遮挡，其镜面像 应完全消失；diffuse 保留 0.3 作间接近似 - ShadowPass 改正面剔除渲阴影图（标准 acne 治法）：封闭网格只写 背面深度，正面深度天然比 ref 大一个表面厚度，从根上消自阴影 acne；代价是单面薄片在光背面时漏写（plane 单面朝上不受影响）
221 lines
9.0 KiB
GLSL
221 lines
9.0 KiB
GLSL
#version 450
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const int MAX_LIGHTS = 4;
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const float PI = 3.14159265359;
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const int kCascadeRes = 1024; // CSM 级联图边长（与引擎 SceneTypes.h 同步）
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struct Light {
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vec4 color; // rgb = 颜色，a = 强度
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vec4 direction; // 方向光：xyz = 方向（已归一）
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vec4 position; // 点光：xyz = 世界位置
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vec4 params; // x = 类型(0=方向,1=点)，y = 衰减半径
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};
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layout(location = 0) in vec2 fragUV;
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layout(location = 1) in vec3 fragNormal;
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layout(location = 2) in vec3 fragWorldPos;
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layout(location = 3) in float fragViewDepth;
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layout(location = 4) in vec2 fragVelocity;
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layout(location = 5) in vec3 fragTangent;
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layout(location = 0) out vec4 outColor;
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layout(location = 1) out vec2 outVelocity; // TAA velocity 附件
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layout(set = 0, binding = 0) uniform UniformBufferObject {
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mat4 view;
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mat4 proj;
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mat4 lightSpace[3]; // CSM 各级联光空间 VP
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vec4 cascadeSplits; // xyz = 级联 0..2 远边界（视图深度）
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vec4 ambientColor;
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Light lights[MAX_LIGHTS];
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mat4 projNoJitter;
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mat4 prevView;
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mat4 prevProj;
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vec4 cameraPos;
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} ubo;
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// 材质纹理槽（binding = Material::Slot）
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layout(set = 1, binding = 0) uniform sampler2D albedoMap;
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layout(set = 1, binding = 1) uniform sampler2D normalMap;
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layout(set = 1, binding = 2) uniform sampler2D metallicRoughnessMap; // G=粗糙度 B=金属度
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layout(set = 1, binding = 3) uniform sampler2D emissiveMap;
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layout(set = 1, binding = 4) uniform sampler2D aoMap; // 环境光遮蔽（R 通道）
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layout(set = 1, binding = 5) uniform MaterialParams {
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vec4 factors; // x = metallic 因子，y = roughness 因子
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} matParams;
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// CSM 阴影（sampler2DShadow：单次采样 = 硬件 2×2 深度比较 PCF）
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layout(set = 2, binding = 0) uniform sampler2DShadow shadowMap0; // CSM 级联 0（最近）
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layout(set = 2, binding = 1) uniform sampler2DShadow shadowMap1; // 级联 1
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layout(set = 2, binding = 2) uniform sampler2DShadow shadowMap2; // 级联 2（最远）
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layout(set = 2, binding = 3) uniform samplerCube irradianceMap; // 漫反射环境光（IBL 阶段②）
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layout(set = 2, binding = 4) uniform samplerCube prefilteredMap; // 镜面环境（mip 分 roughness，阶段③）
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layout(set = 2, binding = 5) uniform sampler2D brdfLut; // BRDF 积分表 (NdotV, roughness) → (scale, bias)
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// 第 0 盏方向光（KeyLight）的 CSM 阴影因子。
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// 级联按视图深度选择；3×3 纹素偏移采样（每 tap 硬件 2×2 PCF，
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// 等效 36 次比较）→ 软阴影边缘；采样器 clamp-to-border 白色：
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// 光视锥外自动 1.0（无阴影），省出界分支
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float ShadowFactor(vec3 N, float viewDepth) {
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int cascade = 2;
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for (int i = 0; i < 3; ++i) {
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if (viewDepth < ubo.cascadeSplits[i]) { cascade = i; break; }
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}
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vec4 ls = ubo.lightSpace[cascade] * vec4(fragWorldPos, 1.0);
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vec3 proj = ls.xyz / ls.w;
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vec2 uv = proj.xy * 0.5 + 0.5;
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vec3 L = normalize(-ubo.lights[0].direction.xyz);
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float bias = max(0.004 * (1.0 - dot(N, L)), 0.0012);
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float texel = 1.0 / float(kCascadeRes); // 与引擎 kCascadeRes 同步
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float shadow = 0.0;
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for (int y = -1; y <= 1; ++y) {
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for (int x = -1; x <= 1; ++x) {
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float lit;
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if (cascade == 0)
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lit = texture(shadowMap0, vec3(uv + vec2(x, y) * texel,
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proj.z - bias));
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else if (cascade == 1)
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lit = texture(shadowMap1, vec3(uv + vec2(x, y) * texel,
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proj.z - bias));
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else
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lit = texture(shadowMap2, vec3(uv + vec2(x, y) * texel,
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proj.z - bias));
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shadow += mix(0.3, 1.0, lit); // 影中保留 0.3 环境感
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}
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}
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return shadow / 9.0;
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}
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// 法线贴图 → 世界空间法线（TBN 构建）。
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// 无切线数据（零向量）或平法线贴图时退回几何法线。
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vec3 MappedNormal(vec3 geomN, vec3 T, vec2 uv) {
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if (dot(T, T) < 1e-4) return geomN;
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vec3 N = geomN;
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vec3 nT = normalize(T - N * dot(N, T)); // 正交化
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vec3 B = cross(N, nT);
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vec3 sampled = texture(normalMap, uv).xyz * 2.0 - 1.0;
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if (dot(sampled, sampled) < 1e-4) return geomN;
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return normalize(nT * sampled.x + B * sampled.y + N * sampled.z);
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}
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// ---- Cook-Torrance BRDF 各项 ----
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float DistributionGGX(float NdotH, float roughness) {
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float a = roughness * roughness;
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float a2 = a * a;
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float d = NdotH * NdotH * (a2 - 1.0) + 1.0;
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return a2 / (PI * d * d);
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}
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float GeometrySmith(float NdotV, float NdotL, float roughness) {
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float r = roughness + 1.0;
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float k = (r * r) / 8.0; // 解析光源用此 k（IBL 才用 IBL 版本）
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float gv = NdotV / (NdotV * (1.0 - k) + k);
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float gl = NdotL / (NdotL * (1.0 - k) + k);
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return gv * gl;
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}
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vec3 FresnelSchlick(float cosTheta, vec3 F0) {
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return F0 + (1.0 - F0) * pow(clamp(1.0 - cosTheta, 0.0, 1.0), 5.0);
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}
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// 粗糙度感知的 Fresnel（IBL 用）：粗糙表面掠射边缘的 F 上升更平缓
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vec3 FresnelSchlickRoughness(float cosTheta, vec3 F0, float roughness) {
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vec3 Fmax = max(vec3(1.0 - roughness), F0);
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return F0 + (Fmax - F0) * pow(clamp(1.0 - cosTheta, 0.0, 1.0), 5.0);
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}
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void main() {
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vec3 albedo = texture(albedoMap, fragUV).rgb;
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vec4 mr = texture(metallicRoughnessMap, fragUV);
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float roughness = clamp(mr.g * matParams.factors.y, 0.045, 1.0);
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float metallic = clamp(mr.b * matParams.factors.x, 0.0, 1.0);
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vec3 emissive = texture(emissiveMap, fragUV).rgb;
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vec3 N = MappedNormal(normalize(fragNormal), fragTangent, fragUV);
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vec3 V = normalize(ubo.cameraPos.xyz - fragWorldPos);
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float NdotV = max(dot(N, V), 1e-4);
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vec3 F0 = mix(vec3(0.04), albedo, metallic); // 电介质基准反射率 4%
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vec3 Lo = vec3(0.0);
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float shade0 = 1.0f; // 【诊断】阴影系数可视化用
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for (int i = 0; i < MAX_LIGHTS; ++i) {
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// 按类型分支：方向光无衰减；点光方向指向光源 + 平方距离衰减
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vec3 L;
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float atten = 1.0;
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if (ubo.lights[i].params.x > 0.5) {
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vec3 toLight = ubo.lights[i].position.xyz - fragWorldPos;
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float d = length(toLight);
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if (d >= ubo.lights[i].params.y) continue;
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L = toLight / d;
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float a = clamp(1.0 - (d * d) /
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(ubo.lights[i].params.y * ubo.lights[i].params.y),
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0.0, 1.0);
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atten = a * a;
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} else {
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L = normalize(-ubo.lights[i].direction.xyz);
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}
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vec3 radiance = ubo.lights[i].color.rgb * ubo.lights[i].color.a * atten;
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float NdotL = max(dot(N, L), 0.0);
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if (NdotL <= 0.0) continue;
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// Cook-Torrance 镜面项
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vec3 H = normalize(V + L);
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float NdotH = max(dot(N, H), 0.0);
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float NdotH2 = max(dot(H, V), 0.0);
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float D = DistributionGGX(NdotH, roughness);
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float G = GeometrySmith(NdotV, NdotL, roughness);
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vec3 F = FresnelSchlick(NdotH2, F0);
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vec3 kS = F;
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vec3 kD = (1.0 - kS) * (1.0 - metallic); // 金属不参与漫反射
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vec3 specular = (D * G * F) /
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max(4.0 * NdotV * NdotL, 1e-4);
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// 阴影只来自第 0 盏方向光（CSM）
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float shade = (i == 0 && ubo.lights[0].params.x < 0.5)
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? ShadowFactor(N, fragViewDepth) : 1.0;
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if (i == 0) shade0 = shade;
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// 漫反射影中保留 0.3（间接光近似）；镜面项是"光源的镜面像"，
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// 光源被遮挡即完全消失——按 shade 重映射（0.3→0，1.0→1）。
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// 否则掠射角下 spec(HDR 8)×0.3 仍是白块，影子比天空还亮
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float shadeSpec = max((shade - 0.3f) / 0.7f, 0.0f);
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Lo += (kD * albedo / PI) * radiance * NdotL * shade
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+ specular * radiance * NdotL * shadeSpec;
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}
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// 环境光：IBL split-sum（阶段②③）。
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// 漫反射：N 采样 irradiance cube（半球 Lambert 预卷积）
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// 镜面：R 采样 pre-filtered cube（mip = roughness 分级）
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// × BRDF LUT 查表得 F 缩放/偏置
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// ambientColor = 用户可调强度/色调乘子
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vec3 F_amb = FresnelSchlickRoughness(NdotV, F0, roughness);
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vec3 kD_amb = (1.0 - F_amb) * (1.0 - metallic);
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vec3 irradiance = texture(irradianceMap, N).rgb;
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float ao = texture(aoMap, fragUV).r;
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vec3 diffuse = kD_amb * irradiance * albedo * ao;
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vec3 R = reflect(-V, N);
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const float kMaxPrefilterMip = 4.0; // 与 Cubemap::kPrefilterMips - 1 同步
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vec3 prefilteredColor = textureLod(prefilteredMap, R,
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roughness * kMaxPrefilterMip).rgb;
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vec2 envBRDF = texture(brdfLut, vec2(NdotV, roughness)).rg;
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vec3 specular = prefilteredColor * (F_amb * envBRDF.x + envBRDF.y);
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vec3 ambient = (diffuse + specular) * ubo.ambientColor.rgb
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* mix(0.4, 1.0, shade0); // 阴影区环境同步衰减（简化遮蔽）
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vec3 color = ambient + Lo + emissive;
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outColor = vec4(color, 1.0);
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outVelocity = fragVelocity;
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}
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