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render/assets/shaders/pbr_forward_ibl.hlsl
T
2026-08-17 06:31:43 +09:00

225 lines
8.3 KiB
HLSL

// 约定:row_major 内存布局
// mul(rowVector, matrix)
// CPU 侧矩阵不转置
#pragma pack_matrix(row_major)
#include "include/pbr_brdf.hlsli"
// [新增] 全局 IBL 资源:b4、t9~t11、s3。
#include "include/ibl.hlsli"
cbuffer CBScene : register(b0)
{
row_major float4x4 gView;
row_major float4x4 gProjection;
float4 gCameraPosition;
float4 gLightDirection; // xyz: 光线从光源射向场景的方向
float4 gLightColorIntensity; // rgb: 线性颜色, w: 强度
float4 gAmbientColorIntensity; // rgb: 线性颜色, w: 强度;IBL 前的临时环境项
float4 gRenderParams; // x: exposure,其余保留
};
cbuffer CBPerMat : register(b1)
{
float4 gBaseColorFactor = float4(0.1f, 0.1f, 0.1f, 1.0f);
float4 gEmissiveFactor = float4(1.0f, 1.0f, 1.0f, 1.0f); // xyz 有效
float4 gPbrParams = float4(1.0f, 1.0f, 1.0f, 1.0f); // x metallic, y roughness, z normalScale, w AO strength
};
cbuffer CBPerObj : register(b2)
{
row_major float4x4 gWorld;
row_major float4x4 gWorldInvTranspose;
};
cbuffer CBShadow : register(b3)
{
row_major float4x4 gLightViewProjection;
float4 gShadowParams; // xy texelSize, z minBias, w slopeBias
};
Texture2D gBaseColorTex : register(t0); // sRGB SRV
Texture2D gNormalTex : register(t1); // Linear SRV
Texture2D gOrmTex : register(t2); // Linear SRV: R=AO, G=Roughness, B=Metallic
Texture2D gEmissiveTex : register(t3); // sRGB SRV
Texture2D<float> gShadowMap : register(t8);
SamplerState gMaterialSampler : register(s0);
SamplerComparisonState gShadowSampler : register(s2);
struct VSInput
{
float3 positionOS : POSITION;
float3 normalOS : NORMAL;
float3 tangentOS : TANGENT;
float2 uv0 : TEXCOORD0;
};
struct VSOutput
{
float4 positionCS : SV_POSITION;
float3 positionWS : POSITION1;
float3 normalWS : NORMAL0;
float3 tangentWS : TANGENT0;
float2 uv0 : TEXCOORD0;
float4 shadowPosition : TEXCOORD1;
};
VSOutput VSMain(VSInput input)
{
VSOutput output;
const float4 positionWS = mul(float4(input.positionOS, 1.0f), gWorld);
const float4 positionVS = mul(positionWS, gView);
output.positionCS = mul(positionVS, gProjection);
output.positionWS = positionWS.xyz;
// 法线必须乘 world 的逆转置矩阵
const float3 normalWS = SafeNormalize(
mul(float4(input.normalOS, 0.0f), gWorldInvTranspose).xyz,
float3(0.0f, 1.0f, 0.0f));
// 切线按普通方向乘 world,再对法线做 Gram-Schmidt 正交化。
float3 tangentWS = mul(float4(input.tangentOS, 0.0f), gWorld).xyz;
tangentWS -= normalWS * dot(normalWS, tangentWS);
tangentWS = SafeNormalize(tangentWS, BuildFallbackTangent(normalWS));
output.normalWS = normalWS;
output.tangentWS = tangentWS;
output.uv0 = input.uv0;
// 沿法线外扩后,获取shadowPos
float4 posWS_bigger = float4((positionWS.xyz + normalWS.xyz * 0.1f), 1.0f);
// output.shadowPosition = mul(positionWS, gLightViewProjection);
output.shadowPosition = mul(posWS_bigger, gLightViewProjection);
// output.shadowPosition = mul(positionWS, gLightViewProjection);
return output;
}
float SampleDirectionalShadow(float4 shadowPosition, float3 n, float3 l)
{
float finalRet = 1.0f;
if (shadowPosition.w > 0.0f)
{
const float3 ndc = shadowPosition.xyz / shadowPosition.w;
const float2 uv = float2(ndc.x * 0.5f + 0.5f, -ndc.y * 0.5f + 0.5f);
if (!any(uv < 0.0f) && !any(uv > 1.0f) && !(ndc.z <= 0.0f) && !(ndc.z >= 1.0f))
{
const float bias = max(
gShadowParams.z,
gShadowParams.w * (1.0f - saturate(dot(n, l))));
float visibility = 0.0f;
[unroll]
for (int y = -1; y <= 1; ++y)
{
[unroll]
for (int x = -1; x <= 1; ++x)
{
const float2 offset = float2(x, y) * gShadowParams.xy;
visibility += gShadowMap.SampleCmpLevelZero(gShadowSampler, uv + offset, ndc.z - bias);
}
}
finalRet = visibility / 9.0f;
}
}
return finalRet;
/* 编译器 warn -> error 多return路径
if (shadowPosition.w <= 0.0f) return 1.0f;
const float3 ndc = shadowPosition.xyz / shadowPosition.w;
const float2 uv = float2(ndc.x * 0.5f + 0.5f, -ndc.y * 0.5f + 0.5f);
if (any(uv < 0.0f) || any(uv > 1.0f) || ndc.z <= 0.0f || ndc.z >= 1.0f) {
return 1.0f;
}
const float bias = max(
gShadowParams.z,
gShadowParams.w * (1.0f - saturate(dot(n, l))));
float visibility = 0.0f;
[unroll]
for (int y = -1; y <= 1; ++y) {
[unroll]
for (int x = -1; x <= 1; ++x) {
const float2 offset = float2(x, y) * gShadowParams.xy;
visibility += gShadowMap.SampleCmpLevelZero(
gShadowSampler, uv + offset, ndc.z - bias);
}
}
return visibility / 9.0f;
*/
}
float4 PSMain(VSOutput input) : SV_TARGET
{
const float4 baseSample = gBaseColorTex.Sample(gMaterialSampler, input.uv0);
const float4 baseColor = baseSample * gBaseColorFactor;
const float3 orm = gOrmTex.Sample(gMaterialSampler, input.uv0).rgb;
const float ao = lerp(1.0f, orm.r, saturate(gPbrParams.w));
const float roughness = clamp(orm.g * gPbrParams.y, 0.045f, 1.0f);
const float metallic = saturate(orm.b * gPbrParams.x);
const float3 normalTS = DecodeNormalMap(gNormalTex.Sample(gMaterialSampler, input.uv0).xyz, gPbrParams.z);
const float3 geometricNormal = SafeNormalize(input.normalWS, float3(0.0f, 1.0f, 0.0f));
const float3 tangent = SafeNormalize(input.tangentWS, BuildFallbackTangent(geometricNormal));
// 当前 VertexData 只有 float3 tangent,暂按 handedness=+1 构造 B。
// 生产版本应把 tangent 改为 float4,并乘 tangent.w 处理镜像 UV。
const float3 bitangent = SafeNormalize(cross(geometricNormal, tangent),
cross(geometricNormal, BuildFallbackTangent(geometricNormal)));
const float3x3 tangentToWorld = float3x3(tangent, bitangent, geometricNormal);
const float3 n = SafeNormalize(mul(normalTS, tangentToWorld), geometricNormal);
const float3 v = SafeNormalize(gCameraPosition.xyz - input.positionWS, geometricNormal);
// Scene.lightDirection 表示光线传播方向,因此表面指向光源的 L 取反。
const float3 l = SafeNormalize(-gLightDirection.xyz, float3(0.0f, 1.0f, 0.0f));
const float3 h = SafeNormalize(v + l, n);
const float nDotL = saturate(dot(n, l));
const float nDotV = saturate(dot(n, v));
const float hDotV = saturate(dot(h, v));
const float3 f0 = lerp(float3(0.04f, 0.04f, 0.04f), baseColor.rgb, metallic);
const float d = DistributionGGX(n, h, roughness);
const float g = GeometrySmith(n, v, l, roughness);
const float3 f = FresnelSchlick(hDotV, f0);
const float3 specular = (d * g * f) / max(4.0f * nDotV * nDotL, PBR_EPSILON);
const float3 kS = f;
const float3 kD = (1.0f - kS) * (1.0f - metallic);
const float3 diffuse = kD * baseColor.rgb / PBR_PI;
const float visibility = SampleDirectionalShadow(input.shadowPosition, n, l);
const float3 radiance = gLightColorIntensity.rgb * gLightColorIntensity.w;
const float3 directLighting = (diffuse + specular) * radiance * nDotL * visibility;
// [修改] IBL 准备完成时使用 irradiance + GGX prefilter + BRDF LUT。
// 若 C:/temp 六面图尚未成功导入,则保留原来的低成本环境项作为回退。
float3 ambientLighting = float3(0.0f, 0.0f, 0.0f);
if (gIblParams.w >= 0.5f)
{
ambientLighting = EvaluateIBL(n, v, baseColor.rgb, metallic, roughness, ao);
}
else
{
const float3 ambientBase = (baseColor.rgb * (1.0f - metallic) + f0 * 0.25f) * ao;
ambientLighting = ambientBase * gAmbientColorIntensity.rgb * gAmbientColorIntensity.w;
}
const float3 emissive = gEmissiveTex.Sample(gMaterialSampler, input.uv0).rgb * gEmissiveFactor.rgb;
float3 color = directLighting + ambientLighting + emissive;
color *= max(gRenderParams.x, 0.0f);
color = ToneMapACES(color);
// Graphic 当前使用 UNORM back buffer,因此在 PS 中完成线性 -> 显示编码。
color = pow(max(color, 0.0f), 1.0f / 2.2f);
return float4(color, baseColor.a);
}