Improved the shadows with a larger texture, PCF for the edges, and only calculating the shadows once.

33-shadow-mapping/config.json

@@ -84,11 +84,11 @@
       {"model": "human", "position": [1.28,  0.0, 1.85],
         "rotation": {"angle": 0.0, "axes": [1.0, 1.0, 1.0]},
         "scale": 1.0,
-        "material": "shiny"},
+        "material": "default"},
       {"model": "human", "position": [3.13, 0.80, 3.04],
         "rotation": {"angle": 0.0, "axes": [1.0, 1.0, 1.0]},
         "scale": 1.0,
-        "material": "shiny"},
+        "material": "default"},
       {"model": "window", "position": [1.5,  0.25,  0.0],
         "rotation": {"angle": 90.0, "axes": [1.0,0.0,0.0]},
         "scale": 1.0,
@@ -107,8 +107,6 @@
     },
     "light": {
       "directional": [
-      ],
-      "positioned": [
         {
           "position": [-2.0, 4.0, -1.0],
           "direction":[0.0, 0.0, 0.0],
@@ -123,6 +121,8 @@
           "on": true
         }
       ],
+      "positioned": [
+      ],
       "spot": [
       ],
       "camera": {

33-shadow-mapping/shaders/33-framebuffers.frag.glsl

@@ -16,17 +16,31 @@ float ShadowCalculation(vec4 fragPosLightSpace, float bias)
 {
     // perform perspective divide
     vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
+
     // transform to [0,1] range
     projCoords = projCoords * 0.5 + 0.5;
+
+    // avoid the frustrum
+    if(projCoords.z > 1.0) return 0.0;
+
     // get closest depth value from light's perspective (using [0,1] range fragPosLight as coords)
     float closestDepth = texture(shadowMap, projCoords.xy).r;
+
     // get depth of current fragment from light's perspective
     float currentDepth = projCoords.z;
+
     // check whether current frag pos is in shadow
+    // PCF
+    float shadow = 0.0;
+    vec2 texelSize = 1.0 / textureSize(shadowMap, 0);
+    for(int x = -1; x <= 1; ++x) {
+      for(int y = -1; y <= 1; ++y) {
+        float pcfDepth = texture(shadowMap, projCoords.xy + vec2(x, y) * texelSize).r;
+        shadow += currentDepth - bias > pcfDepth  ? 1.0 : 0.0;
+      }
+    }
 
-    float shadow = currentDepth - bias > closestDepth  ? 1.0 : 0.0;
+    return shadow / 9.0;
-
-    return shadow;
 }
 
 void main()

33-shadow-mapping/src/scene.cpp

@@ -53,9 +53,17 @@ void Scene::render_scene(GLFWwindow* window, Shader& with_shader) {
 }
 
 void Scene::render_shadows(GLFWwindow* window) {
-  // temporarily use the config.json positioned even though this is doing a directional
-  auto& light_pos = light.positioned.at(0).position;
 
+  glViewport(0, 0, SHADOW_WIDTH, SHADOW_HEIGHT);
+  glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+  glBindFramebuffer(GL_FRAMEBUFFER, depth_FBO);
+  glEnable(GL_DEPTH_TEST);
+  glClear(GL_DEPTH_BUFFER_BIT);
+
+  // temporarily use the config.json positioned even though this is doing a directional
+  for(auto& dir_light : light.directional) {
+    auto& light_pos = dir_light.position;
     glm::mat4 proj = glm::ortho(-10.0f, 10.0f, -10.0f, 10.0f, depth_near_plane, depth_far_plane);
     glm::mat4 view = glm::lookAt(light_pos, glm::vec3(0.0f), glm::vec3(0.0f, 1.0f, 0.0f));
 
@@ -66,14 +74,8 @@ void Scene::render_shadows(GLFWwindow* window) {
     depth_shader.setFloat("near_plane", depth_near_plane);
     depth_shader.setFloat("far_plane", depth_far_plane);
 
-  glViewport(0, 0, SHADOW_WIDTH, SHADOW_HEIGHT);
-  glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-  glBindFramebuffer(GL_FRAMEBUFFER, depth_FBO);
-  glEnable(GL_DEPTH_TEST);
-  glClear(GL_DEPTH_BUFFER_BIT);
-
     render_scene(window, depth_shader);
+  }
 
   glBindFramebuffer(GL_FRAMEBUFFER, 0);
   glDisable(GL_DEPTH_TEST);
@@ -84,7 +86,10 @@ void Scene::render_shadows(GLFWwindow* window) {
 void Scene::render(GLFWwindow* window) {
   auto& with_shader = reflect_on ? reflect_shader : shader;
 
+  if(!shadows_rendered) {
+    shadows_rendered = true;
     render_shadows(window);
+  }
 
   // set depth_map on TEXTURE0
   glActiveTexture(GL_TEXTURE0);
@@ -94,7 +99,7 @@ void Scene::render(GLFWwindow* window) {
   with_shader.setInt("shadowMap", 0);
   // NOTE: in the shader is it viewPos or cameraPos?
   with_shader.setVec3("viewPos", camera.position);
-  with_shader.setVec3("lightPos", light.positioned.at(0).position);
+  with_shader.setVec3("lightPos", light.directional.at(0).position);
   with_shader.setMat4("lightSpaceMatrix", light_space);
 
   framebuffer.begin();
@@ -153,8 +158,11 @@ void Scene::init_shadows() {
   glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, SHADOW_WIDTH, SHADOW_HEIGHT, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+  // set to clamp border with a color of one to remove the frustrum culled part of the shadow
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+  float border_color[4]{1.0f, 1.0f, 1.0f, 1.0f};
+  glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
 
   glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_map, 0);
   glDrawBuffer(GL_NONE);

33-shadow-mapping/src/scene.hpp

@@ -52,7 +52,7 @@ struct Scene {
   Shader depth_dbg_shader{{"shaders/33-shadow_dbg.vert.glsl", "shaders/33-shadow_dbg.frag.glsl", ""}};
   unsigned int depth_FBO = UINT_MAX;
   unsigned int depth_map = UINT_MAX;
-  const unsigned int SHADOW_WIDTH = 1024, SHADOW_HEIGHT = 1024;
+  const unsigned int SHADOW_WIDTH = 1024 * 8, SHADOW_HEIGHT = 1024 * 8;
   float near_plane = 1.0f;
   float far_plane = 100.0f;
 
@@ -74,6 +74,8 @@ struct Scene {
   unsigned int quadVAO = UINT_MAX;
   unsigned int quadVBO = UINT_MAX;
 
+  bool shadows_rendered = false;
+
   Scene(components::Scene& config):
     shader{config.shader},
     reflect_shader{config.reflect_shader},