atdunbg
fa25cb3348
- Cubemap 构造期同步 CPU 半球 Lambert 积分（64×32 网格 ≈2048 采样/像素） 生成 32² irradiance cube（漫反射是超低频信号，分辨率无需高） - shader：kD 用粗糙度感知 FresnelSchlickRoughness + (1-metallic)， N 采样 irradianceMap（Set2 binding 3）替换常数 ambient； ambientColor 保留为强度/色调乘子 - CreateNeutral 兜底：无 HDR 资产时 1×1 常数 cube，描述符恒有效 - FaceDir 改为返回单位方向（equirect 查表要求，修掉未归一化的畸变）
183 lines
7.0 KiB
GLSL
183 lines
7.0 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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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 MaterialParams {
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vec4 factors; // x = metallic 因子，y = roughness 因子
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} matParams;
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layout(set = 2, binding = 0) uniform sampler2D shadowMap0; // CSM 级联 0（最近）
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layout(set = 2, binding = 1) uniform sampler2D shadowMap1; // 级联 1
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layout(set = 2, binding = 2) uniform sampler2D 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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// 第 0 盏方向光（KeyLight）的 CSM 阴影因子：0.3 影中 / 1.0 受光。
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// 级联按视图深度选择；采样器均 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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float closest;
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if (cascade == 0) closest = texture(shadowMap0, uv).r;
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else if (cascade == 1) closest = texture(shadowMap1, uv).r;
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else closest = texture(shadowMap2, uv).r;
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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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return (proj.z - bias > closest) ? 0.3 : 1.0;
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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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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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Lo += (kD * albedo / PI + specular) * radiance * NdotL * shade;
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}
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// 环境光：漫反射辐照度（IBL 阶段②，split-sum 的 diffuse 项）。
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// N 采样预卷积的 irradiance cube（半球 Lambert 积分已在加载期完成）；
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// kD 用粗糙度感知 Fresnel + (1-metallic)（金属无漫反射）。
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// ambientColor = 用户可调强度/色调乘子。镜面项待阶段③ BRDF LUT
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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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vec3 ambient = kD_amb * irradiance * albedo * ubo.ambientColor.rgb;
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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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