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feat: pbr try

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This commit is contained in:
Amir Adal
2025-10-08 19:13:05 +02:00
parent b989d74fca
commit f56e524d05
3 changed files with 139 additions and 59 deletions
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2
src/renderer/renderer.cpp
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@ -23,7 +23,7 @@ Renderer::Renderer()
m_shader.init(
FileManager::read("./src/shaders/simple.vs"),
FileManager::read("./src/shaders/simple.fs")
FileManager::read("./src/shaders/pbr.fs")
);
m_model = glm::mat4(1.f);

92
src/renderer/wavefront.cpp
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@ -393,29 +393,97 @@ Object* Object::LoadFile(const std::string& filename) {
}
// void Object::Render(Shader& shader)
// {
// for (auto &mesh : m_meshes) {
// auto material = GetMaterial(mesh.materialName);
// shader.setFloat("ambientStrength", 0.2f);
// shader.setFloat("shininess", material->GetSpecularWeight());
// shader.setFloat("opacity", material->GetOpacity());
// shader.setBool("useSpecular", material->GetIllumination() >= 2);
// shader.setFloat("specularStrength", 1.0f);
// shader.setVec3("ambientColor", material->GetAmbientColor());
// shader.setVec3("diffuseColor", material->GetDiffuseColor());
// shader.setVec3("specularColor", material->GetSpecularColor());
// if (material->HasDiffuseTexture()) {
// shader.setBool("useTexture", true);
// glActiveTexture(GL_TEXTURE0);
// glBindTexture(GL_TEXTURE_2D, material->GetDiffuseTexture()->GetID());
// shader.setInt("diffuseTex", 0);
// } else {
// shader.setBool("useTexture", false);
// }
// mesh.Render();
// }
// }
void Object::Render(Shader& shader)
{
for (auto &mesh : m_meshes) {
for (auto &mesh : m_meshes)
{
auto material = GetMaterial(mesh.materialName);
shader.setFloat("ambientStrength", 0.2f);
shader.setFloat("shininess", material->GetSpecularWeight());
// --- Basic material properties ---
shader.setFloat("opacity", material->GetOpacity());
shader.setBool("useSpecular", material->GetIllumination() >= 2);
shader.setFloat("specularStrength", 1.0f);
shader.setVec3("ambientColor", material->GetAmbientColor());
shader.setVec3("diffuseColor", material->GetDiffuseColor());
shader.setVec3("specularColor", material->GetSpecularColor());
// Albedo (base color)
shader.setVec3("albedo", material->GetDiffuseColor());
// Metallic and roughness (defaults)
shader.setFloat("metallic", 0.8f);
shader.setFloat("roughness", 0.5f);
shader.setFloat("ao", 1.0f); // default ambient occlusion if none
// --- Optional textures ---
int texUnit = 0;
// Albedo texture
if (material->HasDiffuseTexture()) {
shader.setBool("useTexture", true);
glActiveTexture(GL_TEXTURE0);
shader.setBool("useAlbedoMap", true);
glActiveTexture(GL_TEXTURE0 + texUnit);
glBindTexture(GL_TEXTURE_2D, material->GetDiffuseTexture()->GetID());
shader.setInt("diffuseTex", 0);
shader.setInt("albedoTex", texUnit++);
} else {
shader.setBool("useTexture", false);
shader.setBool("useAlbedoMap", false);
}
// Metallic texture
// if (material->HasMetallicTexture()) {
if (false) {
shader.setBool("useMetallicMap", true);
glActiveTexture(GL_TEXTURE0 + texUnit);
// glBindTexture(GL_TEXTURE_2D, material->GetMetallicTexture()->GetID());
shader.setInt("metallicTex", texUnit++);
} else {
shader.setBool("useMetallicMap", false);
}
// Roughness texture
// if (material->HasRoughnessTexture()) {
if (false) {
shader.setBool("useRoughnessMap", true);
glActiveTexture(GL_TEXTURE0 + texUnit);
// glBindTexture(GL_TEXTURE_2D, material->GetRoughnessTexture()->GetID());
shader.setInt("roughnessTex", texUnit++);
} else {
shader.setBool("useRoughnessMap", false);
}
// AO texture
// if (material->HasAoTexture()) {
if (false) {
shader.setBool("useAoMap", true);
glActiveTexture(GL_TEXTURE0 + texUnit);
// glBindTexture(GL_TEXTURE_2D, material->GetAoTexture()->GetID());
shader.setInt("aoTex", texUnit++);
} else {
shader.setBool("useAoMap", false);
}
// --- Render mesh ---
mesh.Render();
}
}

100
src/shaders/pbr.fs
View File

@ -1,37 +1,42 @@
#version 410 core
// Output color
out vec4 FragColor;
in vec3 vertexPos;
in vec3 vertexNormal;
in vec2 TexCoords;
// Lighting inputs
uniform vec3 lightPos;
uniform vec3 viewPos;
// From Object Renderer
uniform vec3 ambientColor;
uniform vec3 diffuseColor;
uniform vec3 specularColor; // used as F0 (base reflectance)
// Material parameters
uniform vec3 albedo; // Base color (replaces diffuseColor)
uniform float metallic; // 0 = dielectric, 1 = metal
uniform float roughness; // 0 = smooth mirror, 1 = rough
uniform float ao; // Ambient occlusion
uniform float ambientStrength;
uniform float specularStrength;
uniform float shininess; // mapped to roughness
uniform bool useSpecular;
// Textures
uniform sampler2D albedoTex;
uniform sampler2D metallicTex;
uniform sampler2D roughnessTex;
uniform sampler2D aoTex;
uniform bool useAlbedoMap;
uniform bool useMetallicMap;
uniform bool useRoughnessMap;
uniform bool useAoMap;
uniform float opacity;
uniform sampler2D diffuseTex;
uniform bool useTexture;
// Used for emissive light sources
uniform bool isLight;
#define PI 3.14159265359
#define LIGHT_COLOR vec3(1.0, 1.0, 1.0)
// ----------------------------------------------------------------------------
// Helper functions for Cook-Torrance BRDF
// Helper functions
// ----------------------------------------------------------------------------
// Normal Distribution Function (GGX/Trowbridge-Reitz)
float DistributionGGX(vec3 N, vec3 H, float roughness)
{
float a = roughness * roughness;
@ -41,16 +46,15 @@ float DistributionGGX(vec3 N, vec3 H, float roughness)
float num = a2;
float denom = (NdotH2 * (a2 - 1.0) + 1.0);
denom = 3.14159265 * denom * denom;
denom = PI * denom * denom;
return num / denom;
}
// Geometry function (Schlick-GGX)
float GeometrySchlickGGX(float NdotV, float roughness)
{
float r = (roughness + 1.0);
float k = (r * r) / 8.0; // remapped for direct lighting
float k = (r * r) / 8.0;
float num = NdotV;
float denom = NdotV * (1.0 - k) + k;
@ -58,69 +62,77 @@ float GeometrySchlickGGX(float NdotV, float roughness)
return num / denom;
}
// Smith's geometry function
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 ggx1 = GeometrySchlickGGX(NdotV, roughness);
float ggx2 = GeometrySchlickGGX(NdotL, roughness);
float ggx2 = GeometrySchlickGGX(NdotV, roughness);
float ggx1 = GeometrySchlickGGX(NdotL, roughness);
return ggx1 * ggx2;
}
// Fresnel term (Schlick's approximation)
vec3 FresnelSchlick(float cosTheta, vec3 F0)
vec3 fresnelSchlick(float cosTheta, vec3 F0)
{
return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
}
// ----------------------------------------------------------------------------
// Main
// ----------------------------------------------------------------------------
void main()
{
if (isLight) {
vec3 emissive = LIGHT_COLOR * 10.0; // bright light source
FragColor = vec4(emissive, 1.0);
return;
}
// Inputs
vec3 N = normalize(vertexNormal);
vec3 V = normalize(viewPos - vertexPos);
vec3 L = normalize(lightPos - vertexPos);
vec3 H = normalize(V + L);
// Texture or uniform color
vec3 albedo = (useTexture)
? texture(diffuseTex, TexCoords).rgb
: diffuseColor;
// Base color (albedo)
vec3 baseColor = useAlbedoMap ? texture(albedoTex, TexCoords).rgb : albedo;
// Map shininess to roughness (inverse relationship)
float roughness = clamp(1.0 - (shininess / 256.0), 0.05, 1.0);
float metal = useMetallicMap ? texture(metallicTex, TexCoords).r : metallic;
float rough = useRoughnessMap ? texture(roughnessTex, TexCoords).r : roughness;
float aoValue = useAoMap ? texture(aoTex, TexCoords).r : ao;
// Base reflectivity (F0)
vec3 F0 = mix(vec3(0.04), specularColor, specularStrength);
// Reflectance at normal incidence (F0)
vec3 F0 = vec3(0.04); // typical dielectric reflectance
F0 = mix(F0, baseColor, metal); // metals use albedo as F0
// Cook-Torrance BRDF
float NDF = DistributionGGX(N, H, roughness);
float G = GeometrySmith(N, V, L, roughness);
vec3 F = FresnelSchlick(max(dot(H, V), 0.0), F0);
float NDF = DistributionGGX(N, H, rough);
float G = GeometrySmith(N, V, L, rough);
vec3 F = fresnelSchlick(max(dot(H, V), 0.0), F0);
vec3 numerator = NDF * G * F;
float denominator = 4.0 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0) + 0.001;
vec3 specular = numerator / denominator;
// Energy conservation
// kS is specular reflection, kD is diffuse reflection (energy conservation)
vec3 kS = F;
vec3 kD = vec3(1.0) - kS;
kD *= (useSpecular ? 1.0 : 1.0); // keep diffuse always unless specular is off
kD *= 1.0 - metal;
float NdotL = max(dot(N, L), 0.0);
vec3 diffuse = kD * albedo / 3.14159265;
vec3 radiance = LIGHT_COLOR;
vec3 radiance = LIGHT_COLOR; // single light source color/intensity
vec3 Lo = (diffuse + specular) * radiance * NdotL;
vec3 Lo = (kD * baseColor / PI + specular) * radiance * NdotL;
// Ambient (simple, not IBL)
vec3 ambient = ambientStrength * ambientColor * albedo;
// Ambient (IBL approximation using ao)
vec3 ambient = vec3(0.03) * baseColor * aoValue;
vec3 result = ambient + Lo;
vec3 color = ambient + Lo;
// Gamma correction
result = pow(result, vec3(1.0/2.2));
// HDR tonemapping and gamma correction
color = color / (color + vec3(1.0));
color = pow(color, vec3(1.0 / 2.2));
FragColor = vec4(result, opacity);
FragColor = vec4(color, opacity);
}