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

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This commit is contained in:
Zed A. Shaw 2026-09-21 14:49:59 -04:00
parent 621c355876
commit 4747d297e8
4 changed files with 49 additions and 25 deletions
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8
33-shadow-mapping/config.json
View file

@ -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": {

20
33-shadow-mapping/shaders/33-framebuffers.frag.glsl
View file

@ -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;
return shadow / 9.0;
}
void main()

42
33-shadow-mapping/src/scene.cpp
View file

@ -53,18 +53,6 @@ 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;
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));
light_space = proj * view;
depth_shader.use();
depth_shader.setMat4("lightSpaceMatrix", light_space);
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);
@ -73,7 +61,21 @@ void Scene::render_shadows(GLFWwindow* window) {
glEnable(GL_DEPTH_TEST);
glClear(GL_DEPTH_BUFFER_BIT);
render_scene(window, depth_shader);
// 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));
light_space = proj * view;
depth_shader.use();
depth_shader.setMat4("lightSpaceMatrix", light_space);
depth_shader.setFloat("near_plane", depth_near_plane);
depth_shader.setFloat("far_plane", depth_far_plane);
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;
render_shadows(window);
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);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, 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_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);

4
33-shadow-mapping/src/scene.hpp
View file

@ -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},