358 lines
10 KiB
GLSL
358 lines
10 KiB
GLSL
#type vertex
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#version 450 core
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layout(location = 0) in vec3 a_Position;
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layout(location = 1) in vec2 a_TexCoords;
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out vec2 v_TexCoords;
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void main()
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{
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v_TexCoords = a_TexCoords;
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gl_Position = vec4(a_Position, 1.0);
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}
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#type fragment
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#version 450 core
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layout(location = 0) out vec4 o_Color;
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in vec2 v_TexCoords;
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const float PI = 3.14159265359;
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const float F0_NON_METAL = 0.04;
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const float MIN_ROUGHNESS = 0.045;
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#define MAX_DIR_LIGHTS 4
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#define MAX_POINT_LIGHTS 16
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#define MAX_SPOT_LIGHTS 16
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// 优化的数学函数
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float pow5(float x) {
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float x2 = x * x;
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return x2 * x2 * x;
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}
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float sq(float x) {
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return x * x;
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}
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float saturate(float x) {
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return clamp(x, 0.0, 1.0);
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}
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vec3 saturate(vec3 x) {
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return clamp(x, 0.0, 1.0);
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}
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struct DirectionalLight {
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vec3 direction;
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vec3 color;
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float intensity;
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};
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struct PointLight {
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vec3 position;
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vec3 color;
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float intensity;
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float range;
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};
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struct SpotLight {
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vec3 position;
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vec3 direction;
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vec3 color;
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float intensity;
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float range;
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float innerConeAngle;
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float outerConeAngle;
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};
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uniform int u_DirLightCount;
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uniform DirectionalLight u_DirLights[MAX_DIR_LIGHTS];
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uniform int u_PointLightCount;
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uniform PointLight u_PointLights[MAX_POINT_LIGHTS];
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uniform int u_SpotLightCount;
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uniform SpotLight u_SpotLights[MAX_SPOT_LIGHTS];
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// Camera uniform buffer (binding = 0)
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layout(std140, binding = 0) uniform CameraData
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{
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mat4 u_ViewProjection;
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mat4 u_View;
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mat4 u_Projection;
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vec3 u_CameraPosition;
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};
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// Light uniform buffer (binding = 2)
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layout(std140, binding = 2) uniform LightData
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{
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mat4 u_LightSpaceMatrix;
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vec3 u_DirLightDirection;
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float u_DirLightIntensity;
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vec3 u_DirLightColor;
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float _lightPadding0;
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float u_ShadowBias;
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float u_ShadowSoftness;
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int u_EnableShadows;
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int u_NumDirLights;
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float u_AmbientIntensity;
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int u_NumPointLights;
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int u_NumSpotLights;
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};
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uniform sampler2D u_GBufferAlbedo;
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uniform sampler2D u_GBufferNormal;
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uniform sampler2D u_GBufferMaterial;
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uniform sampler2D u_GBufferEmissive;
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uniform sampler2D u_GBufferDepth;
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uniform mat4 u_InverseViewProjection;
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// Shadow mapping
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uniform sampler2D u_ShadowMap;
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// IBL
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uniform bool u_UseIBL;
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uniform samplerCube u_IrradianceMap;
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uniform samplerCube u_PrefilterMap;
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uniform sampler2D u_BRDFLT;
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uniform float u_PrefilterMaxLOD;
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// ============================================================================
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// BRDF 函数
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// ============================================================================
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float D_GGX(float roughness, float NoH) {
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float a = roughness * roughness;
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float a2 = a * a;
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float NoH2 = NoH * NoH;
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float nom = a2;
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float denom = (NoH2 * (a2 - 1.0) + 1.0);
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denom = PI * denom * denom;
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return nom / max(denom, 1e-7);
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}
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float V_SmithGGXCorrelated(float roughness, float NoV, float NoL) {
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float a = roughness * roughness;
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float a2 = a * a;
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float lambdaV = NoL * sqrt(NoV * NoV * (1.0 - a2) + a2);
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float lambdaL = NoV * sqrt(NoL * NoL * (1.0 - a2) + a2);
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return 0.5 / max(lambdaV + lambdaL, 1e-5);
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}
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vec3 fresnelSchlick(float cosTheta, vec3 F0) {
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return F0 + (1.0 - F0) * pow5(saturate(1.0 - cosTheta));
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}
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vec3 fresnelSchlickRoughness(float cosTheta, vec3 F0, float roughness) {
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return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow5(saturate(1.0 - cosTheta));
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}
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float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
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float f90 = 0.5 + 2.0 * roughness * LoH * LoH;
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float lightScatter = 1.0 + (f90 - 1.0) * pow5(1.0 - NoL);
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float viewScatter = 1.0 + (f90 - 1.0) * pow5(1.0 - NoV);
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return lightScatter * viewScatter * (1.0 / PI);
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}
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vec3 ACESFilm(vec3 x) {
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float a = 2.51;
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float b = 0.03;
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float c = 2.43;
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float d = 0.59;
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float e = 0.14;
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return saturate((x * (a * x + b)) / (x * (c * x + d) + e));
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}
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float computeSpecularOcclusion(float NoV, float ao, float roughness) {
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return clamp(pow(NoV + ao, exp2(-16.0 * roughness - 1.0)) - 1.0 + ao, 0.0, 1.0);
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}
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float calculateShadow(vec4 fragPosLightSpace, vec3 normal, vec3 lightDir) {
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vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
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projCoords = projCoords * 0.5 + 0.5;
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if (projCoords.z > 1.0 || projCoords.x < 0.0 || projCoords.x > 1.0 ||
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projCoords.y < 0.0 || projCoords.y > 1.0)
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return 0.0;
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float bias = max(u_ShadowBias * (1.0 - dot(normal, lightDir)), u_ShadowBias * 0.1);
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float shadow = 0.0;
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vec2 texelSize = 1.0 / textureSize(u_ShadowMap, 0);
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int pcfRange = int(u_ShadowSoftness);
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int sampleCount = 0;
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for (int x = -pcfRange; x <= pcfRange; ++x) {
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for (int y = -pcfRange; y <= pcfRange; ++y) {
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float pcfDepth = texture(u_ShadowMap, projCoords.xy + vec2(x, y) * texelSize).r;
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shadow += projCoords.z - bias > pcfDepth ? 1.0 : 0.0;
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sampleCount++;
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}
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}
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shadow /= float(sampleCount);
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return shadow;
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}
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vec3 reconstructWorldPosition(vec2 uv, float depth) {
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vec4 clip = vec4(uv * 2.0 - 1.0, depth * 2.0 - 1.0, 1.0);
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vec4 world = u_InverseViewProjection * clip;
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return world.xyz / max(world.w, 0.0001);
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}
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// ============================================================================
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// 综合光照评估
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// ============================================================================
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vec3 evaluateLighting(vec3 N, vec3 V, vec3 L, vec3 albedo, float roughness,
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float metallic, vec3 F0, float NoV, vec3 radiance, float occlusion) {
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vec3 H = normalize(V + L);
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float NoL = max(dot(N, L), 0.0);
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float NoH = saturate(dot(N, H));
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float LoH = saturate(dot(L, H));
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// 标准 BRDF
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float D = D_GGX(roughness, NoH);
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float V_term = V_SmithGGXCorrelated(roughness, NoV, NoL);
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vec3 kS = fresnelSchlick(LoH, F0);
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vec3 specularBRDF = (D * V_term) * kS;
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// Burley 漫反射
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vec3 kD = (vec3(1.0) - kS) * (1.0 - metallic);
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vec3 diffuseBRDF = kD * albedo * Fd_Burley(roughness, NoV, NoL, LoH);
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vec3 color = (diffuseBRDF + specularBRDF) * NoL;
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return color * radiance * occlusion;
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}
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// ============================================================================
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// 主渲染函数
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// ============================================================================
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void main() {
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float depth = texture(u_GBufferDepth, v_TexCoords).r;
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if (depth >= 1.0)
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discard;
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vec3 albedo = texture(u_GBufferAlbedo, v_TexCoords).rgb;
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vec3 N = normalize(texture(u_GBufferNormal, v_TexCoords).rgb);
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vec3 material = texture(u_GBufferMaterial, v_TexCoords).rgb;
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vec3 emissive = texture(u_GBufferEmissive, v_TexCoords).rgb;
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float roughness = max(material.r, MIN_ROUGHNESS);
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float metallic = saturate(material.g);
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float ao = saturate(material.b);
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vec3 worldPos = reconstructWorldPosition(v_TexCoords, depth);
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vec3 V = normalize(u_CameraPosition - worldPos);
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float NoV = max(dot(N, V), 1e-4);
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vec3 F0 = mix(vec3(F0_NON_METAL), albedo, metallic);
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vec3 Lo = vec3(0.0);
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// Main directional light (with shadow)
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{
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vec3 L = normalize(-u_DirLightDirection);
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vec3 radiance = u_DirLightColor * u_DirLightIntensity;
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float shadow = 0.0;
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if (u_EnableShadows != 0) {
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vec4 fragPosLightSpace = u_LightSpaceMatrix * vec4(worldPos, 1.0);
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shadow = calculateShadow(fragPosLightSpace, N, L);
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}
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Lo += evaluateLighting(N, V, L, albedo, roughness, metallic, F0, NoV, radiance, 1.0 - shadow);
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}
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// Additional directional lights
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for (int i = 0; i < u_DirLightCount; i++) {
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DirectionalLight light = u_DirLights[i];
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vec3 L = normalize(-light.direction);
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vec3 radiance = light.color * light.intensity;
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Lo += evaluateLighting(N, V, L, albedo, roughness, metallic, F0, NoV, radiance, 1.0);
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}
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// Point lights
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for (int i = 0; i < u_PointLightCount; i++) {
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PointLight light = u_PointLights[i];
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vec3 L = light.position - worldPos;
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float dist = length(L);
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if (dist > light.range)
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continue;
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L = normalize(L);
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float distanceAttenuation = 1.0 / (dist * dist + 1.0);
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float windowFactor = sq(saturate(1.0 - sq(sq(dist / light.range))));
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float attenuation = distanceAttenuation * windowFactor;
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vec3 radiance = light.color * light.intensity * attenuation;
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Lo += evaluateLighting(N, V, L, albedo, roughness, metallic, F0, NoV, radiance, 1.0);
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}
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// Spot lights
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for (int i = 0; i < u_SpotLightCount; i++) {
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SpotLight light = u_SpotLights[i];
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vec3 L = light.position - worldPos;
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float dist = length(L);
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if (dist > light.range)
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continue;
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L = normalize(L);
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float theta = dot(L, normalize(light.direction));
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float epsilon = light.innerConeAngle - light.outerConeAngle;
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float spotIntensity = saturate((theta - light.outerConeAngle) / epsilon);
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if (spotIntensity <= 0.0)
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continue;
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float distanceAttenuation = 1.0 / (dist * dist + 1.0);
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float windowFactor = sq(saturate(1.0 - sq(sq(dist / light.range))));
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float attenuation = distanceAttenuation * windowFactor;
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vec3 radiance = light.color * light.intensity * attenuation * spotIntensity;
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Lo += evaluateLighting(N, V, L, albedo, roughness, metallic, F0, NoV, radiance, 1.0);
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}
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// IBL
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vec3 ambient = vec3(0.0);
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if (u_UseIBL) {
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vec3 F = fresnelSchlickRoughness(NoV, F0, roughness);
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vec3 kS = F;
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vec3 kD = (1.0 - kS) * (1.0 - metallic);
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vec3 irradiance = texture(u_IrradianceMap, N).rgb;
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if (dot(irradiance, irradiance) < 0.000001)
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irradiance = vec3(0.03);
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vec3 diffuse = irradiance * albedo;
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vec3 R = reflect(-V, N);
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float lod = roughness * u_PrefilterMaxLOD;
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vec3 prefilteredColor = textureLod(u_PrefilterMap, R, lod).rgb;
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if (dot(prefilteredColor, prefilteredColor) < 0.000001)
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prefilteredColor = vec3(0.03);
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vec2 brdf = texture(u_BRDFLT, vec2(NoV, roughness)).rg;
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float specOcclusion = computeSpecularOcclusion(NoV, ao, roughness);
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vec3 specular = prefilteredColor * (F * brdf.x + brdf.y) * specOcclusion;
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ambient = (kD * diffuse + specular) * ao;
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} else {
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ambient = vec3(u_AmbientIntensity) * albedo * ao;
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}
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vec3 color = ambient + Lo + emissive;
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color = ACESFilm(color);
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color = pow(color, vec3(1.0 / 2.2));
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o_Color = vec4(color, 1.0);
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}
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