Files
Nuake/Data/Shaders/Vulkan/shading.frag
2025-01-31 18:04:43 -05:00

349 lines
9.4 KiB
GLSL

// Transforms
struct ModelData
{
float4x4 model;
};
[[vk::binding(0, 0)]]
StructuredBuffer<ModelData> model : register(t1);
// Vertex
struct Vertex
{
float3 position;
float uv_x;
float3 normal;
float uv_y;
float3 tangent;
float3 bitangent;
};
[[vk::binding(0, 1)]]
StructuredBuffer<Vertex> vertexBuffer : register(t2);
// Samplers
[[vk::binding(0, 2)]]
SamplerState mySampler : register(s0);
// Materials
struct Material
{
bool hasAlbedo;
float3 albedo;
bool hasNormal;
bool hasMetalness;
bool hasRoughness;
bool hasAO;
float metalnessValue;
float roughnessValue;
float aoValue;
int albedoTextureId;
int normalTextureId;
int metalnessTextureId;
int roughnessTextureId;
int aoTextureId;
};
[[vk::binding(0, 3)]]
StructuredBuffer<Material> material;
// Textures
[[vk::binding(0, 4)]]
Texture2D textures[];
// Lights
struct Light
{
float3 position;
int type;
float4 color;
float3 direction;
float outerConeAngle;
float innerConeAngle;
bool castShadow;
int shadowMapTextureId[4];
int transformId[4];
};
[[vk::binding(0, 5)]]
StructuredBuffer<Light> lights;
// Cameras
struct CameraView {
float4x4 View;
float4x4 Projection;
float4x4 ViewProjection;
float4x4 InverseView;
float4x4 InverseProjection;
float3 Position;
float Near;
float Far;
};
[[vk::binding(0, 6)]]
StructuredBuffer<CameraView> cameras;
struct PSInput {
float4 Position : SV_Position;
float2 UV : TEXCOORD0;
};
struct PSOutput {
float4 oColor0 : SV_TARGET;
};
struct ShadingPushConstant
{
int AlbedoInputTextureId;
int DepthInputTextureId;
int NormalInputTextureId;
int MaterialInputTextureId;
int LightCount;
int CameraID;
float cascadeDepth[4];
float AmbientTerm;
};
[[vk::push_constant]]
ShadingPushConstant pushConstants;
float3 WorldPosFromDepth(float depth, float2 uv, float4x4 invProj, float4x4 invView)
{
float z = depth;
float4 clipSpacePosition = float4(uv.x * 2.0 - 1.0, (uv.y * 2.0 - 1.0), z, 1.0f);
float4 viewSpacePosition = mul(invProj, clipSpacePosition);
viewSpacePosition /= viewSpacePosition.w;
float4 worldSpacePosition = mul(invView, viewSpacePosition);
return worldSpacePosition.xyz;
}
float LinearizeDepth(float depth, float nearPlane, float farPlane, bool reverseDepth)
{
if (reverseDepth)
{
// Reverse depth (near plane = 1.0, far plane = 0.0)
return nearPlane * farPlane / lerp(farPlane, nearPlane, depth);
}
else
{
// Standard depth (near plane = 0.0, far plane = 1.0)
return (2.0 * nearPlane * farPlane) / (farPlane + nearPlane - depth * (farPlane - nearPlane));
}
}
float DistributionGGX(float3 N, float3 H, float a)
{
float PI = 3.141592653589793f;
float a2 = a * a;
float NdotH = max(dot(N, H), 0.0);
float NdotH2 = NdotH * NdotH;
float nom = a2;
float denom = (NdotH2 * (a2 - 1.0) + 1.0);
denom = PI * denom * denom;
return nom / denom;
}
float GeometrySchlickGGX(float NdotV, float k)
{
float nom = NdotV;
float denom = NdotV * (1.0 - k) + k;
return nom / denom;
}
float GeometrySmith(float3 N, float3 V, float3 L, float k)
{
float NdotV = max(dot(N, V), 0.0);
float NdotL = max(dot(N, L), 0.0);
float ggx1 = GeometrySchlickGGX(NdotV, k);
float ggx2 = GeometrySchlickGGX(NdotL, k);
return ggx1 * ggx2;
}
float3 fresnelSchlick(float cosTheta, float3 F0)
{
return F0 + (1.0 - F0) * pow(max(1.0 - cosTheta, 0.0), 5.0);
}
float3 fresnelSchlickRoughness(float cosTheta, float3 F0, float roughness)
{
float roughnessTerm = 1.0f - roughness;
return F0 + (max(float3(roughnessTerm, roughnessTerm, roughnessTerm), F0) - F0) * pow(max(1.0 - cosTheta, 0.0), 5.0);
}
float linearDepth(float z, float near, float far) {
return near * far / (far - z * (far - near));
}
int GetCSMSplit(float depth)
{
for(int i = 0; i < 4; i++)
{
float csmSplitDepth = pushConstants.cascadeDepth[i];
if(depth < csmSplitDepth + 0.000001)
{
return i;
}
}
return 0;
}
float ShadowCalculation(Light light, float3 fragPos, float3 normal)
{
// Find correct CSM splits from depth
CameraView camView = cameras[pushConstants.CameraID];
float depth = length(fragPos - camView.Position);
int splitIndex = GetCSMSplit(depth);
// Calculate shadows for found split
CameraView lightView = cameras[light.transformId[splitIndex]];
int shadowMap = light.shadowMapTextureId[0];
float4 fragLightSpace = mul(lightView.Projection, mul(lightView.View, float4(fragPos, 1.0)));
float3 projCoords = fragLightSpace.xyz / fragLightSpace.w;
projCoords.xy = projCoords.xy * 0.5 + 0.5;
if (projCoords.x < 0.0 || projCoords.x > 1.0 || projCoords.y < 0.0 || projCoords.y > 1.0) {
return 1.0;
}
//projCoords.y = 1.0 - projCoords.y;
float currentDepth = projCoords.z;
float bias = max(0.005 * (1.0 - dot(normal, light.direction)), 0.0005);
float shadowMapDepth = textures[light.shadowMapTextureId[splitIndex]].Sample(mySampler, projCoords.xy).r;
return (currentDepth > shadowMapDepth);//> 0.0 ? 1.0 : 0.0;
}
PSOutput main(PSInput input)
{
PSOutput output;
CameraView camView = cameras[pushConstants.CameraID];
int depthTexture = pushConstants.DepthInputTextureId;
float depth = textures[depthTexture].Sample(mySampler, input.UV).r;
float3 worldPos = WorldPosFromDepth(depth, input.UV, camView.InverseProjection, camView.InverseView);
int albedoTextureId = pushConstants.AlbedoInputTextureId;
float3 albedo = textures[albedoTextureId].Sample(mySampler, input.UV).xyz;
float3 normal = textures[pushConstants.NormalInputTextureId].Sample(mySampler, input.UV).rgb;
normal = normal * 2.0f - 1.0f;
float4 materialSample = textures[pushConstants.MaterialInputTextureId].Sample(mySampler, input.UV);
float metallic = materialSample.r;
float ao = materialSample.g;
float roughness = materialSample.b;
float3 N = normal;
float3 V = normalize(camView.Position - worldPos);
float3 R = reflect(-V, N);
float3 F0 = float3(0.04, 0.04, 0.04);
F0 = lerp(F0, albedo, metallic);
Light directionalLight;
bool foundDirectional = false;
for(int i = 0; i < pushConstants.LightCount; i++)
{
Light light = lights[i];
if(light.type == 0)
{
directionalLight = light;
foundDirectional = true;
break;
}
}
const float PI = 3.141592653589793f;
float3 Lo = float3(0.0, 0.0, 0.0);
float shadow = 1.0f;
if(foundDirectional == false)
{
shadow = 1.0f;
}
//Directional
if(foundDirectional)
{
Light light = directionalLight;
float3 L = normalize(light.direction);
float attenuation = 1.0f;
if(light.castShadow == true)
{
shadow *= ShadowCalculation(light, worldPos, N);
//output.oColor0 = float4(albedo * 0.1 + float3(shadow, shadow, shadow), 1);
//return output;
}
// TODO: Shadow
float3 radiance = light.color.rgb * attenuation;
float3 H = normalize(V + L);
float NDF = DistributionGGX(N, H, roughness);
float G = GeometrySmith(N, V, L, roughness);
float3 F = fresnelSchlick(max(dot(H, V), 0.0), F0);
float3 nominator = NDF * G * F;
float denominator = 4 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001; // 0.001 to prevent divide by zero.
float3 specular = nominator / denominator;
float3 kS = F;
float3 kD = float3(1.0, 1.0, 1.0) - kS;
kD *= 1.0 - metallic;
float NdotL = max(dot(N, L), 0.0);
Lo += (kD * albedo / PI + specular) * radiance * NdotL * shadow;
}
// other lights
for(int i = 0; i < pushConstants.LightCount; i++)
{
Light light = lights[i];
float3 L = normalize(light.position - worldPos);
float distance = length(light.position - worldPos);
float attenuation = 1.0 / (distance * distance);
float3 radiance = float3(0, 0, 0);
if(light.type == 1) // point light
{
radiance = light.color * attenuation;
}
else if(light.type == 2)
{
float theta = dot(L, normalize(-light.direction));
float epsilon = light.innerConeAngle - light.outerConeAngle;
float intensity = clamp((theta - light.outerConeAngle) / epsilon, 0.0, 1.0);
radiance = light.color * intensity;
}
float3 H = normalize(V + L);
float NDF = DistributionGGX(N, H, roughness);
float G = GeometrySmith(N, V, L, roughness);
float3 F = fresnelSchlick(max(dot(H, V), 0.0), F0);
float3 nominator = NDF * G * F;
float denominator = 4 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001; // 0.001 to prevent divide by zero.
float3 specular = nominator / denominator;
float3 kS = F;
float3 kD = float3(1.0, 1.0, 1.0) - kS;
kD *= 1.0 - metallic;
float NdotL = max(dot(N, L), 0.0);
Lo += (kD * albedo / PI + specular) * radiance * NdotL;
}
float3 F = fresnelSchlickRoughness(max(dot(N, V), 0.0), F0, roughness);
float3 kS = F;
float3 kD = 1.0 - kS;
kD *= 1.0 - metallic;
float3 ambient = (albedo) * ao * pushConstants.AmbientTerm;
float3 color = (ambient) + Lo;
output.oColor0 = float4(color, 1);
return output;
}