497 lines
15 KiB
GLSL
497 lines
15 KiB
GLSL
// -----------------------------
|
|
// -- Based on Hazel PBR shader --
|
|
// -----------------------------
|
|
// Note: this shader is still very much in progress. There are likely many bugs and future additions that will go in.
|
|
// Currently heavily updated.
|
|
//
|
|
// References upon which this is based:
|
|
// - Unreal Engine 4 PBR notes (https://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_notes_v2.pdf)
|
|
// - Frostbite's SIGGRAPH 2014 paper (https://seblagarde.wordpress.com/2015/07/14/siggraph-2014-moving-frostbite-to-physically-based-rendering/)
|
|
// - Michał Siejak's PBR project (https://github.com/Nadrin)
|
|
// - My implementation from years ago in the Sparky engine (https://github.com/TheCherno/Sparky)
|
|
#type vertex
|
|
#version 430 core
|
|
|
|
layout(location = 0) in vec3 a_Position;
|
|
layout(location = 1) in vec3 a_Normal;
|
|
layout(location = 2) in vec3 a_Tangent;
|
|
layout(location = 3) in vec3 a_Binormal;
|
|
layout(location = 4) in vec2 a_TexCoord;
|
|
|
|
layout(location = 5) in ivec4 a_BoneIndices;
|
|
layout(location = 6) in vec4 a_BoneWeights;
|
|
|
|
const int MAX_BONES = 100;
|
|
uniform mat4 u_BoneTransforms[100];
|
|
|
|
uniform mat4 u_ViewProjectionMatrix;
|
|
uniform mat4 u_ViewMatrix;
|
|
uniform mat4 u_Transform;
|
|
|
|
uniform mat4 u_LightSpaceMatrix;
|
|
|
|
out VertexOutput
|
|
{
|
|
vec3 WorldPosition;
|
|
vec3 Normal;
|
|
vec2 TexCoord;
|
|
mat3 WorldNormals;
|
|
mat3 WorldTransform;
|
|
vec3 Binormal;
|
|
vec3 ViewPosition;
|
|
vec4 FragPosLightSpace;
|
|
} vs_Output;
|
|
|
|
void main()
|
|
{
|
|
mat4 boneTransform = u_BoneTransforms[a_BoneIndices[0]] * a_BoneWeights[0];
|
|
boneTransform += u_BoneTransforms[a_BoneIndices[1]] * a_BoneWeights[1];
|
|
boneTransform += u_BoneTransforms[a_BoneIndices[2]] * a_BoneWeights[2];
|
|
boneTransform += u_BoneTransforms[a_BoneIndices[3]] * a_BoneWeights[3];
|
|
|
|
vec4 localPosition = boneTransform * vec4(a_Position, 1.0);
|
|
|
|
vs_Output.WorldPosition = vec3(u_Transform * boneTransform * vec4(a_Position, 1.0));
|
|
vs_Output.Normal = mat3(u_Transform) * mat3(boneTransform) * a_Normal;
|
|
vs_Output.TexCoord = vec2(a_TexCoord.x, 1.0 - a_TexCoord.y);
|
|
vs_Output.WorldNormals = mat3(u_Transform) * mat3(a_Tangent, a_Binormal, a_Normal);
|
|
vs_Output.WorldTransform = mat3(u_Transform);
|
|
vs_Output.Binormal = a_Binormal;
|
|
|
|
vs_Output.FragPosLightSpace = u_LightSpaceMatrix * u_Transform * localPosition;
|
|
|
|
vs_Output.ViewPosition = vec3(u_ViewMatrix * vec4(vs_Output.WorldPosition, 1.0));
|
|
|
|
// gl_Position = u_ViewProjectionMatrix * u_Transform * vec4(a_Position, 1.0);
|
|
gl_Position = u_ViewProjectionMatrix * u_Transform * localPosition;
|
|
}
|
|
|
|
#type fragment
|
|
#version 430 core
|
|
|
|
const float PI = 3.141592;
|
|
const float Epsilon = 0.00001;
|
|
|
|
const int LightCount = 1;
|
|
const vec3 Fdielectric = vec3(0.04);
|
|
|
|
struct DirectionalLight {
|
|
vec3 Direction;
|
|
vec3 Radiance;
|
|
float Intensity;
|
|
bool CastShadows;
|
|
};
|
|
|
|
struct PointLight {
|
|
vec3 Position;
|
|
vec3 Radiance;
|
|
float Intensity;
|
|
float Range;
|
|
bool CastShadows;
|
|
};
|
|
|
|
struct SpotLight {
|
|
vec3 Position;
|
|
vec3 Direction;
|
|
vec3 Radiance;
|
|
float Intensity;
|
|
float Range;
|
|
float InnerConeCos;
|
|
float OuterConeCos;
|
|
bool CastShadows;
|
|
};
|
|
|
|
in VertexOutput
|
|
{
|
|
vec3 WorldPosition;
|
|
vec3 Normal;
|
|
vec2 TexCoord;
|
|
mat3 WorldNormals;
|
|
mat3 WorldTransform;
|
|
vec3 Binormal;
|
|
vec3 ViewPosition;
|
|
vec4 FragPosLightSpace;
|
|
} vs_Input;
|
|
|
|
layout(location = 0) out vec4 color;
|
|
layout(location = 1) out vec4 o_BloomColor;
|
|
|
|
uniform DirectionalLight u_DirectionalLights;
|
|
uniform vec3 u_CameraPosition;
|
|
|
|
uniform int u_PointLightCount;
|
|
uniform PointLight u_PointLights;
|
|
|
|
uniform int u_SpotLightCount;
|
|
uniform SpotLight u_SpotLights;
|
|
|
|
|
|
// PBR
|
|
uniform sampler2D u_AlbedoTexture;
|
|
uniform sampler2D u_NormalTexture;
|
|
uniform sampler2D u_MetalnessTexture;
|
|
uniform sampler2D u_RoughnessTexture;
|
|
|
|
// environment
|
|
uniform samplerCube u_EnvRadianceTex;
|
|
uniform samplerCube u_EnvIrradianceTex;
|
|
|
|
// BRDF LUT
|
|
uniform sampler2D u_BRDFLUTTexture;
|
|
|
|
uniform float u_IBLContribution;
|
|
uniform float u_BloomThreshold;
|
|
uniform float u_EnvMapRotation;
|
|
|
|
// baseColor
|
|
uniform vec3 u_AlbedoColor;
|
|
uniform float u_Metalness;
|
|
uniform float u_Roughness;
|
|
|
|
// textureToggle
|
|
uniform float u_AlbedoTexToggle;
|
|
uniform float u_NormalTexToggle;
|
|
uniform float u_MetalnessTexToggle;
|
|
uniform float u_RoughnessTexToggle;
|
|
|
|
// shadow
|
|
uniform sampler2D u_ShadowMap;
|
|
uniform float u_ShadowBias;
|
|
uniform float u_ShadowSoftness;
|
|
uniform float u_ShadowIntensity;
|
|
uniform int u_ShadowEnabled;
|
|
|
|
// Emissive
|
|
uniform sampler2D u_EmissiveTexture;
|
|
uniform float u_EmissiveTexToggle;
|
|
uniform vec3 u_EmissiveColor;
|
|
uniform float u_EmissiveIntensity;
|
|
|
|
|
|
struct PBRParameters
|
|
{
|
|
vec3 Albedo;
|
|
float Roughness;
|
|
float Metalness;
|
|
vec3 Normal;
|
|
vec3 View;
|
|
float NdotV;
|
|
};
|
|
|
|
PBRParameters m_Params;
|
|
|
|
// ---------- PBR param func ----------
|
|
float ndfGGX(float cosLh, float roughness)
|
|
{
|
|
float alpha = roughness * roughness;
|
|
float alphaSq = alpha * alpha;
|
|
float denom = (cosLh * cosLh) * (alphaSq - 1.0) + 1.0;
|
|
return alphaSq / (PI * denom * denom);
|
|
}
|
|
|
|
float GeometrySchlickGGX(float NdotV, float roughness)
|
|
{
|
|
float r = (roughness + 1.0);
|
|
float k = (r * r) / 8.0;
|
|
float nom = NdotV;
|
|
float denom = NdotV * (1.0 - k) + k;
|
|
return nom / denom;
|
|
}
|
|
|
|
float GeometrySmith(vec3 N, vec3 V, vec3 L, float roughness)
|
|
{
|
|
float NdotV = max(dot(N, V), 0.0);
|
|
float NdotL = max(dot(N, L), 0.0);
|
|
float ggx2 = GeometrySchlickGGX(NdotV, roughness);
|
|
float ggx1 = GeometrySchlickGGX(NdotL, roughness);
|
|
return ggx1 * ggx2;
|
|
}
|
|
|
|
vec3 fresnelSchlick(vec3 F0, float cosTheta)
|
|
{
|
|
return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
|
|
}
|
|
|
|
vec3 fresnelSchlickRoughness(vec3 F0, float cosTheta, float roughness)
|
|
{
|
|
return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow(1.0 - cosTheta, 5.0);
|
|
}
|
|
|
|
// ---------- direction light ----------
|
|
vec3 ComputeDirectionalLight(DirectionalLight light, vec3 F0, PBRParameters params)
|
|
{
|
|
vec3 L = normalize(-light.Direction);
|
|
vec3 Lradiance = light.Radiance * light.Intensity;
|
|
|
|
vec3 Lh = normalize(L + params.View);
|
|
float cosLi = max(0.0, dot(params.Normal, L));
|
|
float cosLh = max(0.0, dot(params.Normal, Lh));
|
|
|
|
vec3 F = fresnelSchlick(F0, max(0.0, dot(Lh, params.View)));
|
|
float D = ndfGGX(cosLh, params.Roughness);
|
|
float G = GeometrySmith(params.Normal, params.View, L, params.Roughness);
|
|
|
|
vec3 kd = (1.0 - F) * (1.0 - params.Metalness);
|
|
vec3 diffuseBRDF = kd * params.Albedo;
|
|
vec3 specularBRDF = (F * D * G) / max(Epsilon, 4.0 * cosLi * params.NdotV);
|
|
|
|
return (diffuseBRDF + specularBRDF) * Lradiance * cosLi;
|
|
}
|
|
|
|
vec3 ComputePointLight(PointLight light, vec3 F0, PBRParameters params, vec3 worldPos)
|
|
{
|
|
vec3 lightVec = light.Position - worldPos;
|
|
float dist = length(lightVec);
|
|
if (dist > light.Range) return vec3(0.0);
|
|
|
|
vec3 L = lightVec / dist;
|
|
vec3 Lradiance = light.Radiance * light.Intensity;
|
|
|
|
// 距离衰减：通常使用平方衰减，但为避免分母为零，加一个小值
|
|
float attenuation = 1.0 / (dist * dist + 0.0001);
|
|
|
|
// 可选：范围平滑衰减
|
|
float rangeFactor = clamp(1.0 - (dist / light.Range), 0.0, 1.0);
|
|
rangeFactor = rangeFactor * rangeFactor; // 平滑
|
|
attenuation *= rangeFactor;
|
|
|
|
vec3 Lh = normalize(L + params.View);
|
|
float cosLi = max(0.0, dot(params.Normal, L));
|
|
float cosLh = max(0.0, dot(params.Normal, Lh));
|
|
|
|
vec3 F = fresnelSchlick(F0, max(0.0, dot(Lh, params.View)));
|
|
float D = ndfGGX(cosLh, params.Roughness);
|
|
float G = GeometrySmith(params.Normal, params.View, L, params.Roughness);
|
|
|
|
vec3 kd = (1.0 - F) * (1.0 - params.Metalness);
|
|
vec3 diffuseBRDF = kd * params.Albedo;
|
|
vec3 specularBRDF = (F * D * G) / max(Epsilon, 4.0 * cosLi * params.NdotV);
|
|
|
|
return (diffuseBRDF + specularBRDF) * Lradiance * cosLi * attenuation;
|
|
}
|
|
|
|
vec3 ComputeSpotLight(SpotLight light, vec3 F0, PBRParameters params, vec3 worldPos)
|
|
{
|
|
vec3 lightVec = light.Position - worldPos;
|
|
float dist = length(lightVec);
|
|
if (dist > light.Range) return vec3(0.0);
|
|
|
|
vec3 L = lightVec / dist;
|
|
vec3 Lradiance = light.Radiance * light.Intensity;
|
|
|
|
// 距离衰减
|
|
float attenuation = 1.0 / (dist * dist + 0.0001);
|
|
float rangeFactor = clamp(1.0 - (dist / light.Range), 0.0, 1.0);
|
|
rangeFactor = rangeFactor * rangeFactor;
|
|
attenuation *= rangeFactor;
|
|
|
|
// 角度衰减（聚光锥）
|
|
float cosAngle = dot(-L, normalize(light.Direction)); // 光方向指向外，所以用 -L
|
|
if (cosAngle < light.OuterConeCos) return vec3(0.0);
|
|
float angleFalloff = (cosAngle - light.OuterConeCos) / (light.InnerConeCos - light.OuterConeCos);
|
|
angleFalloff = clamp(angleFalloff, 0.0, 1.0);
|
|
attenuation *= angleFalloff;
|
|
|
|
vec3 Lh = normalize(L + params.View);
|
|
float cosLi = max(0.0, dot(params.Normal, L));
|
|
float cosLh = max(0.0, dot(params.Normal, Lh));
|
|
|
|
vec3 F = fresnelSchlick(F0, max(0.0, dot(Lh, params.View)));
|
|
float D = ndfGGX(cosLh, params.Roughness);
|
|
float G = GeometrySmith(params.Normal, params.View, L, params.Roughness);
|
|
|
|
vec3 kd = (1.0 - F) * (1.0 - params.Metalness);
|
|
vec3 diffuseBRDF = kd * params.Albedo;
|
|
vec3 specularBRDF = (F * D * G) / max(Epsilon, 4.0 * cosLi * params.NdotV);
|
|
|
|
return (diffuseBRDF + specularBRDF) * Lradiance * cosLi * attenuation;
|
|
}
|
|
|
|
|
|
|
|
vec3 Lighting(vec3 F0)
|
|
{
|
|
vec3 result = vec3(0.0);
|
|
for(int i = 0; i < LightCount; i++)
|
|
{
|
|
vec3 Li = u_DirectionalLights.Direction;
|
|
vec3 Lradiance = u_DirectionalLights.Radiance * u_DirectionalLights.Intensity;
|
|
vec3 Lh = normalize(Li + m_Params.View);
|
|
|
|
float cosLi = max(0.0, dot(m_Params.Normal, Li));
|
|
float cosLh = max(0.0, dot(m_Params.Normal, Lh));
|
|
|
|
vec3 F = fresnelSchlick(F0, max(0.0, dot(Lh, m_Params.View)));
|
|
float D = ndfGGX(cosLh, m_Params.Roughness);
|
|
float G = GeometrySmith(m_Params.Normal, m_Params.View, Li, m_Params.Roughness);
|
|
|
|
vec3 kd = (1.0 - F) * (1.0 - m_Params.Metalness);
|
|
vec3 diffuseBRDF = kd * m_Params.Albedo;
|
|
|
|
vec3 specularBRDF = (F * D * G) / max(Epsilon, 4.0 * cosLi * m_Params.NdotV);
|
|
|
|
result += (diffuseBRDF + specularBRDF) * Lradiance * cosLi;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// ---------- IBL ----------
|
|
vec3 RotateVectorAboutY(float angle, vec3 vec)
|
|
{
|
|
angle = radians(angle);
|
|
mat3 rotationMatrix = mat3(
|
|
vec3(cos(angle), 0.0, sin(angle)),
|
|
vec3(0.0, 1.0, 0.0),
|
|
vec3(-sin(angle), 0.0, cos(angle))
|
|
);
|
|
return rotationMatrix * vec;
|
|
}
|
|
|
|
vec3 IBL(vec3 F0, vec3 Lr)
|
|
{
|
|
vec3 irradiance = texture(u_EnvIrradianceTex, m_Params.Normal).rgb;
|
|
vec3 F = fresnelSchlickRoughness(F0, m_Params.NdotV, m_Params.Roughness);
|
|
vec3 kd = (1.0 - F) * (1.0 - m_Params.Metalness);
|
|
vec3 diffuseIBL = m_Params.Albedo * irradiance;
|
|
|
|
int u_EnvRadianceTexLevels = textureQueryLevels(u_EnvRadianceTex);
|
|
vec3 specularIrradiance = textureLod(
|
|
u_EnvRadianceTex,
|
|
RotateVectorAboutY(u_EnvMapRotation, Lr),
|
|
m_Params.Roughness * u_EnvRadianceTexLevels
|
|
).rgb;
|
|
|
|
vec2 specularBRDF = texture(u_BRDFLUTTexture, vec2(m_Params.NdotV, 1.0 - m_Params.Roughness)).rg;
|
|
vec3 specularIBL = specularIrradiance * (F * specularBRDF.x + specularBRDF.y);
|
|
|
|
return kd * diffuseIBL + specularIBL;
|
|
}
|
|
|
|
// shadow
|
|
|
|
float calculateShadow(vec4 fragPosLightSpace, vec3 normal, vec3 lightDir)
|
|
{
|
|
// Perspective divide
|
|
vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
|
|
|
|
// Transform to [0,1] range
|
|
projCoords = projCoords * 0.5 + 0.5;
|
|
|
|
// If outside shadow map bounds, assume no shadow
|
|
if(projCoords.z > 1.0 || projCoords.x < 0.0 || projCoords.x > 1.0 || projCoords.y < 0.0 || projCoords.y > 1.0)
|
|
return 0.0;
|
|
|
|
// Get closest depth value from light's perspective
|
|
float closestDepth = texture(u_ShadowMap, projCoords.xy).r;
|
|
float currentDepth = projCoords.z;
|
|
|
|
// Calculate bias based on surface angle
|
|
float bias = max(u_ShadowBias * (1.0 - dot(normal, lightDir)), u_ShadowBias * 0.1);
|
|
|
|
// PCF (Percentage Closer Filtering) for soft shadows
|
|
float shadow = 0.0;
|
|
vec2 texelSize = 1.0 / textureSize(u_ShadowMap, 0);
|
|
int pcfRange = int(u_ShadowSoftness);
|
|
int sampleCount = 0;
|
|
|
|
for(int x = -pcfRange; x <= pcfRange; ++x)
|
|
{
|
|
for(int y = -pcfRange; y <= pcfRange; ++y)
|
|
{
|
|
float pcfDepth = texture(u_ShadowMap, projCoords.xy + vec2(x, y) * texelSize).r;
|
|
shadow += currentDepth - bias > pcfDepth ? 1.0 : 0.0;
|
|
sampleCount++;
|
|
}
|
|
}
|
|
shadow /= float(sampleCount);
|
|
|
|
return shadow;
|
|
}
|
|
|
|
|
|
float ComputeShadow(vec4 fragPosLightSpace, float NdotL)
|
|
{
|
|
if (u_ShadowEnabled == 0) return 1.0;
|
|
|
|
vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
|
|
projCoords = projCoords * 0.5 + 0.5;
|
|
|
|
if (projCoords.x < 0.0 || projCoords.x > 1.0 ||
|
|
projCoords.y < 0.0 || projCoords.y > 1.0 ||
|
|
projCoords.z > 1.0) return 1.0;
|
|
|
|
float closestDepth = texture(u_ShadowMap, projCoords.xy).r;
|
|
float currentDepth = projCoords.z;
|
|
|
|
float bias = max(u_ShadowBias * (1.0 - NdotL), u_ShadowBias * 0.5);
|
|
|
|
float shadow = (currentDepth - bias) > closestDepth ? 1.0 : 0.0;
|
|
return mix(1.0, 1.0 - u_ShadowIntensity, shadow);
|
|
}
|
|
|
|
|
|
void main()
|
|
{
|
|
float alpha = 1.0;
|
|
if (u_AlbedoTexToggle > 0.5) {
|
|
vec4 albedoWithAlpha = texture(u_AlbedoTexture, vs_Input.TexCoord);
|
|
m_Params.Albedo = albedoWithAlpha.rgb;
|
|
alpha = albedoWithAlpha.a;
|
|
} else {
|
|
m_Params.Albedo = u_AlbedoColor;
|
|
alpha = 1.0;
|
|
}
|
|
|
|
m_Params.Metalness = u_MetalnessTexToggle > 0.5 ? texture(u_MetalnessTexture, vs_Input.TexCoord).r : u_Metalness;
|
|
m_Params.Roughness = u_RoughnessTexToggle > 0.5 ? texture(u_RoughnessTexture, vs_Input.TexCoord).r : u_Roughness;
|
|
m_Params.Roughness = max(m_Params.Roughness, 0.05);
|
|
|
|
// normal
|
|
m_Params.Normal = normalize(vs_Input.Normal);
|
|
if (u_NormalTexToggle > 0.5)
|
|
{
|
|
m_Params.Normal = normalize(2.0 * texture(u_NormalTexture, vs_Input.TexCoord).rgb - 1.0);
|
|
m_Params.Normal = normalize(vs_Input.WorldNormals * m_Params.Normal);
|
|
}
|
|
|
|
m_Params.View = normalize(u_CameraPosition - vs_Input.WorldPosition);
|
|
m_Params.NdotV = max(dot(m_Params.Normal, m_Params.View), 0.0);
|
|
|
|
vec3 Lr = 2.0 * m_Params.NdotV * m_Params.Normal - m_Params.View;
|
|
|
|
vec3 F0 = mix(Fdielectric, m_Params.Albedo, m_Params.Metalness);
|
|
|
|
float shadowFactor = 1.0;
|
|
if (u_ShadowEnabled > 0.5) {
|
|
float shadow = calculateShadow(vs_Input.FragPosLightSpace, m_Params.Normal, u_DirectionalLights.Direction);
|
|
shadowFactor = 1.0 - shadow;
|
|
}
|
|
|
|
|
|
vec3 lightContribution = u_DirectionalLights.Intensity > 0.0 ? Lighting(F0) * shadowFactor : vec3(0.0);
|
|
|
|
if(u_PointLightCount > 0)
|
|
lightContribution += ComputePointLight(u_PointLights, F0, m_Params, vs_Input.WorldPosition);
|
|
|
|
if(u_SpotLightCount > 0)
|
|
lightContribution += ComputeSpotLight(u_SpotLights, F0, m_Params, vs_Input.WorldPosition);
|
|
|
|
|
|
vec3 iblContribution = IBL(F0, Lr) * u_IBLContribution;
|
|
|
|
vec3 emissive = u_EmissiveColor;
|
|
if (u_EmissiveTexToggle > 0.5) {
|
|
emissive = texture(u_EmissiveTexture, vs_Input.TexCoord).rgb;
|
|
}
|
|
emissive *= u_EmissiveIntensity;
|
|
|
|
vec3 finalRGB = lightContribution + iblContribution + emissive;
|
|
vec4 finalColor = vec4(finalRGB, alpha);
|
|
|
|
color = finalColor;
|
|
|
|
// Bloom
|
|
float brightness = dot(color.rgb, vec3(0.2126, 0.7152, 0.0722));
|
|
o_BloomColor = brightness > u_BloomThreshold ? color : vec4(0.0, 0.0, 0.0, 1.0);
|
|
}
|