basic PBR example

examples/shaders/basic_pbr.c

@@ -0,0 +1,170 @@
+/*******************************************************************************************
+*
+*   raylib [core] example - Model Defuse Normal Shader (adapted for HTML5 platform)
+*
+*   This example is prepared to compile for PLATFORM_WEB and PLATFORM_DESKTOP
+*   As you will notice, code structure is slightly different to the other examples...
+*   To compile it for PLATFORM_WEB just uncomment #define PLATFORM_WEB at beginning
+*
+*   This example has been created using raylib 5.0 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2023-2024 Afan OLOVCIC (@_DevDad)  2015 Ramon Santamaria (@raysan5)
+*   Model: "Old Rusty Car" (https://skfb.ly/LxRy) by Renafox is licensed under Creative Commons Attribution-NonCommercial (http://creativecommons.org/licenses/by-nc/4.0/).
+********************************************************************************************/
+
+#include "raylib.h"
+
+#if defined(PLATFORM_WEB)
+#include <emscripten/emscripten.h>
+#endif
+
+#define RPBR_IMPLEMENTATION
+#include "rpbr.h"
+
+#if defined(PLATFORM_DESKTOP)
+#define GLSL_VERSION            330
+#else   // PLATFORM_ANDROID, PLATFORM_WEB
+#define GLSL_VERSION            120
+#endif
+
+
+//----------------------------------------------------------------------------------
+// Main Entry Point
+//----------------------------------------------------------------------------------
+int main()
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    SetConfigFlags(FLAG_MSAA_4X_HINT);
+    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - basic pbr");
+
+    // Define the camera to look into our 3d world
+    Camera camera = { 0 };
+    camera.position = (Vector3){ 2.0f, 2.0f, 6.0f };    // Camera position
+    camera.target = (Vector3){ 0.0f, 0.5f, 0.0f };      // Camera looking at point
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };          // Camera up vector (rotation towards target)
+    camera.fovy = 45.0f;                                // Camera field-of-view Y
+    camera.projection = CAMERA_PERSPECTIVE;             // Camera projection type
+
+
+    Shader shader = LoadShader(TextFormat("resources/shaders/glsl%i/pbr.vs",GLSL_VERSION),
+                               TextFormat("resources/shaders/glsl%i/pbr.fs",GLSL_VERSION));
+
+
+
+    PBRModel model = PBRModelLoad("resources/models/old_car_new.glb");
+    //if we use obj file formator if model doesn't have tangents we have to calculate MeshTangents
+    //by using raylib function GenMeshTangents(mesh) for example: obj file doesn't support tangents
+    //GenMeshTangents(&model.model.meshes[0]); 
+
+    PBRMaterial model_mat = (PBRMaterial){0};
+    PBRMaterialSetup(&model_mat, shader, NULL); //environment = NULL for now
+    PBRLoadTextures(&model_mat, PBR_TEXTURE_ALBEDO, "resources/old_car_d.png");
+    PBRLoadTextures(&model_mat, PBR_TEXTURE_MRA, "resources/old_car_mra.png");
+    PBRLoadTextures(&model_mat, PBR_TEXTURE_NORMAL, "resources/old_car_n.png");
+    PBRLoadTextures(&model_mat, PBR_TEXTURE_EMISSIVE, "resources/old_car_e.png");
+    PBRSetColor(&model_mat,PBR_COLOR_EMISSIVE, (Color){255,162,0,255});
+    PBRSetVec2(&model_mat, PBR_VEC2_TILING,(Vector2){0.5,0.5});
+    PBRSetMaterial(&model,&model_mat,0);
+
+    PBRModel floor = PBRModelLoad("resources/models/plane.glb");
+    PBRMaterial floor_mat = (PBRMaterial){0};
+    PBRMaterialSetup(&floor_mat, shader, NULL);
+    PBRLoadTextures(&floor_mat, PBR_TEXTURE_ALBEDO, "resources/road_a.png");
+    PBRLoadTextures(&floor_mat, PBR_TEXTURE_MRA, "resources/road_mra.png");
+    PBRLoadTextures(&floor_mat, PBR_TEXTURE_NORMAL, "resources/road_n.png");
+    PBRSetVec2(&floor_mat, PBR_VEC2_TILING,(Vector2){0.5,0.5});
+    PBRSetMaterial(&floor,&floor_mat,0);
+
+    shader.locs[SHADER_LOC_VECTOR_VIEW] = GetShaderLocation(shader, "viewPos");
+    int numOfLightsLoc = GetShaderLocation(shader, "numOfLights");
+    int numOfLights = 4;
+    SetShaderValue(shader, numOfLightsLoc, &numOfLights, SHADER_UNIFORM_INT);
+
+    Color ambCol = (Color){26,32,135,255};
+    float ambIntens = 0.02;
+
+    int albedoLoc = GetShaderLocation(shader, "albedo");
+    PBRSetAmbient(shader,ambCol,ambIntens);
+
+    // Create lights
+    PBRLight lights[MAX_LIGHTS] = { 0 };
+    lights[0] = PBRLightCreate(LIGHT_POINT, (Vector3){ -1, 1, -2 }, (Vector3){0,0,0}, YELLOW,4, shader);
+    lights[1] = PBRLightCreate(LIGHT_POINT, (Vector3){ 2,  1, 1 }, (Vector3){0,0,0}, GREEN,3.3, shader);
+    lights[2] = PBRLightCreate(LIGHT_POINT, (Vector3){ -2, 1, 1 }, (Vector3){0,0,0}, RED,8.3, shader);
+    lights[3] = PBRLightCreate(LIGHT_POINT, (Vector3){ 1,  1, -2 }, (Vector3){0,0,0}, BLUE,2, shader);
+    SetShaderValueV(shader, GetShaderLocation(shader, "lights"), lights, SHADER_UNIFORM_FLOAT, numOfLights);
+
+    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second-------------------------------------------------------------
+
+    int emissiveCnt = 0;
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        UpdateCamera(&camera, CAMERA_ORBITAL);
+
+        // Update the shader with the camera view vector (points towards { 0.0f, 0.0f, 0.0f })
+        float cameraPos[3] = {camera.position.x, camera.position.y, camera.position.z};
+        SetShaderValue(shader, shader.locs[SHADER_LOC_VECTOR_VIEW], cameraPos, SHADER_UNIFORM_VEC3);
+
+        // Check key inputs to enable/disable lights
+        if (IsKeyPressed(KEY_Y)) { lights[0].enabled = !lights[0].enabled; }
+        if (IsKeyPressed(KEY_G)) { lights[1].enabled = !lights[1].enabled; }
+        if (IsKeyPressed(KEY_R)) { lights[2].enabled = !lights[2].enabled; }
+        if (IsKeyPressed(KEY_B)) { lights[3].enabled = !lights[3].enabled; }
+
+        // Update light values (actually, only enable/disable them)
+        for (int i = 0; i < MAX_LIGHTS; i++) PBRLightUpdate(shader, lights[i]);
+        emissiveCnt--;
+        if(emissiveCnt<=0){
+            emissiveCnt = GetRandomValue(0,20);
+            PBRSetFloat(&model_mat,PBR_PARAM_EMISSIVE,(float)GetRandomValue(0,100)/100);
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+            ClearBackground(BLACK);
+            BeginMode3D(camera);
+
+                PBRDrawModel(floor, (Vector3){0,0,0}, 5.0f);
+                PBRDrawModel(model, (Vector3) {0, 0.0, 0}, 0.005);
+
+                // Draw spheres to show where the lights are
+                for (int i = 0; i < MAX_LIGHTS; i++) {
+                    Color col = (Color) {lights[i].color[0] * 255, lights[i].color[1] * 255, lights[i].color[2] * 255,
+                                         lights[i].color[3] * 255};
+                    if (lights[i].enabled) DrawSphereEx(lights[i].position, 0.2f, 8, 8, col);
+                    else DrawSphereWires(lights[i].position, 0.2f, 8, 8, ColorAlpha(col, 0.3f));
+                }
+            EndMode3D();
+
+            DrawText("(c) Old Rusty Car model by Renafox (https://skfb.ly/LxRy)", screenWidth - 320, screenHeight - 20, 10, GRAY);
+            DrawFPS(10, 10);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    //--------------------------------------------------------------------------------------
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+
+    UnloadModel(floor.model);           // Unload model
+    UnloadModel(model.model);           // Unload model
+    UnloadShader(shader);               // Unload Shader
+    UnloadPBRMaterial(floor_mat);       // Unload PBRMaterial
+    UnloadPBRMaterial(model_mat);       // Unload PBRMaterial
+
+    CloseWindow();              // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+    }

examples/shaders/resources/shaders/glsl100/pbr.fs

@@ -0,0 +1,156 @@
+#version 100
+
+precision mediump float;
+
+#define MAX_LIGHTS              4
+#define LIGHT_DIRECTIONAL       0
+#define LIGHT_POINT             1
+#define PI 3.14159265358979323846
+
+struct Light {
+    int enabled;
+    int type;
+    vec3 position;
+    vec3 target;
+    vec4 color;
+    float intensity;
+};
+
+// Input vertex attributes (from vertex shader)
+varying in vec3 fragPosition;
+varying in vec2 fragTexCoord;
+varying in vec4 fragColor;
+varying in vec3 fragNormal;
+varying in vec4 shadowPos;
+varying in mat3 TBN;
+
+
+// Input uniform values
+uniform int numOfLights;
+uniform sampler2D albedoMap;
+uniform sampler2D mraMap;
+uniform sampler2D normalMap;
+uniform sampler2D emissiveMap; // r: Hight g:emissive
+
+uniform vec2 tiling;
+uniform vec2 offset;
+
+uniform int useTexAlbedo;
+uniform int useTexNormal;
+uniform int useTexMRA;
+uniform int useTexEmissive;
+
+uniform vec4  albedoColor;
+uniform vec4  emissiveColor;
+uniform float normalValue;
+uniform float metallicValue;
+uniform float roughnessValue;
+uniform float aoValue;
+uniform float emissivePower;
+
+// Input lighting values
+uniform Light lights[MAX_LIGHTS];
+uniform vec3 viewPos;
+
+uniform vec3 ambientColor;
+uniform float ambient;
+
+// refl in range  0 to 1
+// returns base reflectivity to 1
+// incrase reflectivity when surface view at larger angle
+vec3 schlickFresnel(float hDotV,vec3 refl)
+{
+        return refl + (1.0 - refl) * pow(1.0 - hDotV,5.0);
+}
+
+float ggxDistribution(float nDotH,float roughness)
+{
+        float a = roughness * roughness * roughness * roughness;
+        float d = nDotH * nDotH * (a - 1.0) + 1.0;
+        d = PI * d * d;
+        return a / max(d,0.0000001);
+}
+
+float geomSmith(float nDotV,float nDotL,float roughness)
+{
+        float r = roughness + 1.0;
+        float k = r * r / 8.0;
+        float ik = 1.0 - k;
+        float ggx1 = nDotV / (nDotV * ik + k);
+        float ggx2 = nDotL / (nDotL * ik + k);
+        return ggx1 * ggx2;
+}
+
+vec3 pbr(){
+        vec3 albedo = texture2D(albedoMap,vec2(fragTexCoord.x*tiling.x+offset.x,fragTexCoord.y*tiling.y+offset.y)).rgb;
+        albedo = vec3(albedoColor.x*albedo.x,albedoColor.y*albedo.y,albedoColor.z*albedo.z);
+        float metallic = clamp(metallicValue,0.0,1.0);
+        float roughness = clamp(roughnessValue,0.0,1.0);
+        float ao = clamp(aoValue,0.0,1.0);
+        if(useTexMRA == 1) {
+            vec4 mra = texture2D(mraMap, vec2(fragTexCoord.x * tiling.x + offset.x, fragTexCoord.y * tiling.y + offset.y));
+            metallic = clamp(mra.r+metallicValue,0.04,1.0);
+            roughness = clamp(mra.g+roughnessValue,0.04,1.0);
+            ao = (mra.b+aoValue)*0.5;
+        }
+
+
+
+        vec3 N = normalize(fragNormal);
+        if(useTexNormal == 1) {
+            N = texture2D(normalMap, vec2(fragTexCoord.x * tiling.x + offset.y, fragTexCoord.y * tiling.y + offset.y)).rgb;
+            N = normalize(N * 2.0 - 1.0);
+            N = normalize(N * TBN);
+        }
+
+        vec3 V = normalize(viewPos - fragPosition);
+
+        vec3 e = vec3(0);
+        e = (texture2D(emissiveMap, vec2(fragTexCoord.x*tiling.x+offset.x, fragTexCoord.y*tiling.y+offset.y)).rgb).g * emissiveColor.rgb*emissivePower * float(useTexEmissive);
+
+        //return N;//vec3(metallic,metallic,metallic);
+        //if  dia-electric use base reflectivity of 0.04 otherwise ut is a metal use albedo as base reflectivity
+        vec3 baseRefl = mix(vec3(0.04),albedo.rgb,metallic);
+        vec3 Lo = vec3(0.0);  // acumulate lighting lum
+
+        for(int i=0;i<numOfLights;++i){
+
+            vec3 L = normalize(lights[i].position - fragPosition);  // calc light vector
+            vec3 H = normalize(V + L);                              // calc halfway bisecting vector
+            float dist = length(lights[i].position - fragPosition); // calc distance to light
+            float attenuation = 1.0 / (dist * dist * 0.23);                // calc attenuation
+            vec3 radiance = lights[i].color.rgb * lights[i].intensity * attenuation;         // calc input radiance,light energy comming in
+
+            //Cook-Torrance BRDF distribution function
+            float nDotV = max(dot(N,V),0.0000001);
+            float nDotL = max(dot(N,L),0.0000001);
+            float hDotV = max(dot(H,V),0.0);
+            float nDotH = max(dot(N,H),0.0);
+            float D = ggxDistribution(nDotH,roughness); // larger the more micro-facets aligned to H
+            float G = geomSmith(nDotV,nDotL,roughness); // smaller the more micro-facets shadow
+            vec3 F = schlickFresnel(hDotV, baseRefl);  // fresnel proportion of specular reflectance
+
+            vec3 spec = (D * G * F) / (4.0 * nDotV * nDotL);
+            // difuse and spec light can't be above 1.0
+            // kD = 1.0 - kS  diffuse component is equal 1.0 - spec comonent
+            vec3 kD = vec3(1.0) - F;
+            //mult kD by the inverse of metallnes , only non-metals should have diffuse light
+            kD *= 1.0 - metallic;
+            Lo += ((kD * albedo.rgb / PI + spec) * radiance * nDotL)*float(lights[i].enabled); // angle of light has impact on result
+        }
+        vec3 ambient_final = (ambientColor + albedo)* ambient * 0.5;
+        return ambient_final+Lo*ao+e;
+}
+
+void main()
+{
+       vec3 color = pbr();
+
+        //HDR tonemapping
+        color = pow(color,color + vec3(1.0));
+        //gamma correction
+        color = pow(color,vec3(1.0/2.2));
+
+        gl_FragColor = vec4(color,1.0);
+
+}