Files
QuaternionEngine/shaders/mesh.frag
2025-12-20 23:43:34 +09:00

100 lines
3.8 KiB
GLSL

#version 450
#extension GL_GOOGLE_include_directive : require
#include "input_structures.glsl"
#include "ibl_common.glsl"
#include "lighting_common.glsl"
layout (location = 0) in vec3 inNormal;
layout (location = 1) in vec3 inColor;
layout (location = 2) in vec2 inUV;
layout (location = 3) in vec3 inWorldPos;
layout (location = 4) in vec4 inTangent;
layout (location = 0) out vec4 outFragColor;
void main()
{
// Base color with material factor and texture
vec4 baseTex = texture(colorTex, inUV);
// Alpha from baseColor texture and factor (glTF spec)
float alpha = clamp(baseTex.a * materialData.colorFactors.a, 0.0, 1.0);
// Optional alpha-cutout support for MASK materials (alphaCutoff > 0)
float alphaCutoff = materialData.extra[2].x;
if (alphaCutoff > 0.0 && alpha < alphaCutoff)
{
discard;
}
vec3 albedo = inColor * baseTex.rgb * materialData.colorFactors.rgb;
// glTF: metallicRoughnessTexture uses G=roughness, B=metallic
vec2 mrTex = texture(metalRoughTex, inUV).gb;
float roughness = clamp(mrTex.x * materialData.metal_rough_factors.y, 0.04, 1.0);
float metallic = clamp(mrTex.y * materialData.metal_rough_factors.x, 0.0, 1.0);
// Normal mapping path for forward/transparent pipeline
// Expect UNORM normal map; support BC5 (RG) by reconstructing Z from XY.
vec2 enc = texture(normalMap, inUV).xy * 2.0 - 1.0;
float normalScale = max(materialData.extra[0].x, 0.0);
enc *= normalScale;
float z2 = 1.0 - dot(enc, enc);
float nz = z2 > 0.0 ? sqrt(z2) : 0.0;
vec3 Nm = vec3(enc, nz);
vec3 Nn = normalize(inNormal);
vec3 T = normalize(inTangent.xyz);
vec3 B = normalize(cross(Nn, T)) * inTangent.w;
vec3 N = normalize(T * Nm.x + B * Nm.y + Nn * Nm.z);
vec3 camPos = vec3(inverse(sceneData.view)[3]);
vec3 V = normalize(camPos - inWorldPos);
// Directional sun term (no shadows in forward path)
vec3 Lsun = normalize(-sceneData.sunlightDirection.xyz);
vec3 sunBRDF = evaluate_brdf(N, V, Lsun, albedo, roughness, metallic);
vec3 direct = sunBRDF * sceneData.sunlightColor.rgb * sceneData.sunlightColor.a;
// Punctual point lights
uint pointCount = sceneData.lightCounts.x;
for (uint i = 0u; i < pointCount; ++i)
{
direct += eval_point_light(sceneData.punctualLights[i], inWorldPos, N, V, albedo, roughness, metallic);
}
// Spot lights
uint spotCount = sceneData.lightCounts.y;
for (uint i = 0u; i < spotCount; ++i)
{
direct += eval_spot_light(sceneData.spotLights[i], inWorldPos, N, V, albedo, roughness, metallic);
}
// IBL: specular from equirect 2D mips; diffuse from SH
vec3 R = reflect(-V, N);
float levels = float(textureQueryLevels(iblSpec2D));
float lod = ibl_lod_from_roughness(roughness, levels);
vec2 uv = dir_to_equirect(R);
vec3 prefiltered = textureLod(iblSpec2D, uv, lod).rgb;
vec2 brdf = texture(iblBRDF, vec2(max(dot(N, V), 0.0), roughness)).rg;
vec3 F0 = mix(vec3(0.04), albedo, metallic);
vec3 specIBL = prefiltered * (F0 * brdf.x + brdf.y);
vec3 diffIBL = (1.0 - metallic) * albedo * sh_eval_irradiance(N);
// Ambient occlusion from texture + strength (indirect only)
// extra[0].y = AO strength, extra[0].z = hasAO flag (1 = use AO texture)
float hasAO = materialData.extra[0].z;
float aoStrength = clamp(materialData.extra[0].y, 0.0, 1.0);
float aoTex = texture(occlusionTex, inUV).r;
float ao = 1.0;
if (hasAO > 0.5)
{
ao = 1.0 - aoStrength + aoStrength * aoTex;
}
// Emissive from texture and factor
vec3 emissiveFactor = materialData.extra[1].rgb;
vec3 emissiveTex = texture(emissiveTex, inUV).rgb;
vec3 emissive = emissiveTex * emissiveFactor;
vec3 indirect = diffIBL + specIBL;
vec3 color = direct + indirect * ao + emissive;
outFragColor = vec4(color, alpha);
}