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I made a program that displays some textures like this it works just fine:
void Texture::render(int w, int h, uint8_t *buffer)
{
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
glGenerateMipmap(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
shader.use();
unsigned int transformLoc = glGetUniformLocation(shader.ID, "transform");
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(transform));
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
}
And this is the fragment shader:
#version 300 es
precision mediump float;
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
uniform sampler2D texture1;
void main()
{
vec4 nColor = texture(texture1, TexCoord);
FragColor = vec4(nColor.r, nColor.g, nColor.b, 1);
}
Normally this works fine, but I need to pass an argument to decide the transparency (currently it's 1 in the FragColor = vec4(...))
I've tried doing this to no avail:
void Texture::render(int w, int h, uint8_t *buffer)
{
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
glGenerateMipmap(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
shader.use();
unsigned int transformLoc = glGetUniformLocation(shader.ID, "transform");
glUniform1f(transformLoc, 0.5f);
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, glm::value_ptr(transform));
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
}
And simply changed the fragment shader to this:
#version 300 es
precision mediump float;
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
uniform sampler2D texture1;
uniform float transparency;
void main()
{
vec4 nColor = texture(texture1, TexCoord);
FragColor = vec4(nColor.r, nColor.g, nColor.b, transparency);
}
How am I supposed to properly do this? I want to pass transparency as an additional argument.
Enable Blending (also see LearnOpenGL - Blending) and:
unsigned int transparencyLoc = glGetUniformLocation(shader.ID, "transparency");
float alpha = ...;
glUniform1f(transparencyLoc, alpha);
I suggest multiplying the alpha channel of the texture and the value of the uniform in the fragment shader:
uniform sampler2D texture1;
uniform float transparency;
void main()
{
vec4 nColor = texture(texture1, TexCoord);
FragColor = vec4(nColor.rgb, nColor.a * transparency);
}
I am trying to make a simple deferred lighting scene in OpenGL, but the problem after the implementation of a 1 point light I got a 180 degree lighted surface :
screenshot 1 :
screenshot 2 :
Here is my code :
Material shaderGeometryPass("Shaders/deff_shader.vers", "Shaders/deff_shader.frags");
Material shaderLightingPass("Shaders/deff_light.vers", "Shaders/deff_light.frags");
shaderLightingPass.Use();
shaderLightingPass.setInt("gPosition", 0);
shaderLightingPass.setInt("gNormal", 1);
shaderLightingPass.setInt("gAlbedoSpec", 2);
// configure g-buffer framebuffer
// ------------------------------
unsigned int gBuffer;
glGenFramebuffers(1, &gBuffer);
glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
unsigned int gPosition, gNormal, gAlbedoSpec;
// position color buffer
glGenTextures(1, &gPosition);
glBindTexture(GL_TEXTURE_2D, gPosition);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, SCR_weight, SCR_height, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, gPosition, 0);
// normal color buffer
glGenTextures(1, &gNormal);
glBindTexture(GL_TEXTURE_2D, gNormal);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, SCR_weight, SCR_height, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, gNormal, 0);
// color + specular color buffer
glGenTextures(1, &gAlbedoSpec);
glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SCR_weight, SCR_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, gAlbedoSpec, 0);
// tell OpenGL which color attachments we'll use (of this framebuffer) for rendering
unsigned int attachments[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
glDrawBuffers(3, attachments);
// create and attach depth buffer (renderbuffer)
unsigned int rboDepth;
glGenRenderbuffers(1, &rboDepth);
glBindRenderbuffer(GL_RENDERBUFFER, rboDepth);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, SCR_weight, SCR_height);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rboDepth);
// finally check if framebuffer is complete
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
std::cout << "Framebuffer not complete!" << std::endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
while (!glfwWindowShouldClose(window) == 0)
{
camera.ComputeMatrices();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// 1. geometry pass: render scene's geometry/color data into gbuffer
// -----------------------------------------------------------------
glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
for (size_t i = 0; i < mScene.all_children.size(); i++)
{
if (mScene.all_children[i]->Get_component_id(Comp_Mesh) >= 0)
{
bool get_suc = false;
RMesh &get_mesh = meshs.GetMesh(mScene.all_children[i]->Get_component_id(Comp_Mesh), get_suc);
if (get_suc)
{
if (!get_mesh.mesh_available) continue;
get_mesh.UseVertex();
shaderGeometryPass.Use();
glm::mat4 ModelMatrix = glm::scale(translate(mat4(1.0), mScene.all_children[i]->transform.Position), mScene.all_children[i]->transform.Scale);
shaderGeometryPass.SetMat4("projection", camera.GetProjectionMatrix());
shaderGeometryPass.SetMat4("view", camera.GetViewMatrix());
shaderGeometryPass.SetMat4("model", ModelMatrix);
// Bind our texture in Texture Unit 0
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture1));
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture2));
// Set our "myTextureSampler" sampler to use Texture Unit 0
glUniform1i(shaderGeometryPass.GetUniform("texture_diffuse"), 0);
glUniform1i(shaderGeometryPass.GetUniform("texture_specular"), 1);
// 1rst attribute buffer : vertices
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, get_mesh.vertexbuffer);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0);
// 2nd attribute buffer : UVs
glEnableVertexAttribArray(1);
glBindBuffer(GL_ARRAY_BUFFER, get_mesh.uvbuffer);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, (void*)0);
// 3rd attribute buffer : normals
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, get_mesh.normalbuffer);
glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 0, (void*)0);
// Index buffer
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, get_mesh.elementbuffer);
// Draw the triangles !
glDrawElements(GL_TRIANGLES, get_mesh.indices.size(), GL_UNSIGNED_SHORT, (void*)0);
glDisableVertexAttribArray(0);
glDisableVertexAttribArray(1);
glDisableVertexAttribArray(2);
get_mesh.EndVertex();
}
}
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// 2. lighting pass: calculate lighting by iterating over a screen filled quad pixel-by-pixel using the gbuffer's content.
// -----------------------------------------------------------------------------------------------------------------------
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shaderLightingPass.Use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, gPosition);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, gNormal);
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
// send light relevant uniforms
for (size_t i = 0; i < mScene.all_children.size(); i++)
{
if (mScene.all_children[i]->Get_component_id(Comp_PointLight) >= 0)
{
int g;
if (Point_lights.GetLight(mScene.all_children[i]->Get_component_id(Comp_PointLight), &g))
{
if (Point_lights.lights[g].light_id == mScene.all_children[i]->Get_component_id(Comp_PointLight))
{
Point_lights.lights[g].Position = mScene.all_children[i]->transform.Position;
}
}
}
if (Point_lights.lights.size() > 0)
{
shaderLightingPass.SetVec3("lights[0].Position", Point_lights.lights[0].Position);
shaderLightingPass.SetVec3("lights[0].Color", Point_lights.lights[0].Color);
// update attenuation parameters and calculate radius
const float constant = 1.0;
const float linear = Point_lights.lights[0].Range;
const float quadratic = 1.8;
shaderLightingPass.SetFloat("lights[0].Linear", linear);
shaderLightingPass.SetFloat("lights[0].Quadratic", quadratic);
// then calculate radius of light volume/sphere
const float maxBrightness = Point_lights.lights[0].Energy; //std::fmaxf(std::fmaxf(Point_lights.lights[0].Color.r, Point_lights.lights[0].Color.g), Point_lights.lights[0].Color.b);
float radius = (-linear + std::sqrt(linear * linear - 4 * quadratic * (constant - (256.0f ) * maxBrightness))) / (2.0f * quadratic);
shaderLightingPass.SetFloat("lights[0].Radius", radius);
}
}
shaderLightingPass.SetVec3("viewPos", camera.transform.Position);
renderQuad();
// Swap buffers
glfwSwapBuffers(window);
glfwPollEvents();
}
"deff_light.vers" shader :
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTexCoords;
out vec2 TexCoords;
void main()
{
TexCoords = aTexCoords;
gl_Position = vec4(aPos, 1.0);
}
"deff_light.frags" shader :
#version 330 core
out vec4 FragColor;
in vec2 TexCoords;
uniform sampler2D gPosition;
uniform sampler2D gNormal;
uniform sampler2D gAlbedoSpec;
struct Light {
vec3 Position;
vec3 Color;
float Linear;
float Quadratic;
float Radius;
};
const int NR_LIGHTS = 1;
uniform Light lights[NR_LIGHTS];
uniform vec3 viewPos;
void main()
{
// retrieve data from gbuffer
vec3 FragPos = texture(gPosition, TexCoords).rgb;
vec3 Normal = texture(gNormal, TexCoords).rgb;
vec3 Diffuse = texture(gAlbedoSpec, TexCoords).rgb;
float Specular = texture(gAlbedoSpec, TexCoords).a;
// then calculate lighting as usual
vec3 lighting = Diffuse * 0.1; // hard-coded ambient component
vec3 viewDir = normalize(viewPos - FragPos);
for(int i = 0; i < NR_LIGHTS; ++i)
{
// calculate distance between light source and current fragment
float distance = length(lights[i].Position - FragPos);
if(distance < lights[i].Radius)
{
// diffuse
vec3 lightDir = normalize(lights[i].Position - FragPos);
vec3 diffuse = max(dot(Normal, lightDir), 0.0) * Diffuse * lights[i].Color;
// specular
vec3 halfwayDir = normalize(lightDir + viewDir);
float spec = pow(max(dot(Normal, halfwayDir), 0.0), 16.0);
vec3 specular = lights[i].Color * spec * Specular;
// attenuation
float attenuation = 1.0 / (1.0 + lights[i].Linear * distance + lights[i].Quadratic * distance * distance);
diffuse *= attenuation;
specular *= attenuation;
lighting += diffuse + specular;
}
}
FragColor = vec4(lighting, 1.0);
}
"deff_shader.vers" shader:
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;
out vec3 FragPos;
out vec2 TexCoords;
out vec3 Normal;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
vec4 worldPos = model * vec4(aPos, 1.0);
FragPos = worldPos.xyz;
TexCoords = aTexCoords;
mat3 normalMatrix = transpose(inverse(mat3(model)));
Normal = normalMatrix * aNormal;
gl_Position = projection * view * worldPos;
}
"deff_shader.frags" shader:
#version 330 core
layout (location = 0) out vec3 gPosition;
layout (location = 1) out vec3 gNormal;
layout (location = 2) out vec4 gAlbedoSpec;
in vec2 TexCoords;
in vec3 FragPos;
in vec3 Normal;
uniform sampler2D texture_diffuse1;
uniform sampler2D texture_specular1;
void main()
{
// store the fragment position vector in the first gbuffer texture
gPosition = FragPos;
// also store the per-fragment normals into the gbuffer
gNormal = normalize(Normal);
// and the diffuse per-fragment color
gAlbedoSpec.rgb = texture(texture_diffuse1, TexCoords).rgb;
// store specular intensity in gAlbedoSpec's alpha component
gAlbedoSpec.a = texture(texture_specular1, TexCoords).r;
}
What I am doing wrong ?
Any help please ?
I'm trying to get shadow mapping working on my project. I followed the tutorial at Learn OpenGL Tutorial. For some reason, I can't see the shadows though, only the specularity from the lighting code in the fragment shader.
Image from render.
Here's how I do the framebuffer setup (Where frameBuffer and DepthMap are two global GLuint):
void createFrameBuffer()
{
glGenFramebuffers(1, &frameBuffer);
glGenTextures(1, &DepthMap);
glBindTexture(GL_TEXTURE_2D, DepthMap);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT,
SHADOW_WIDTH, SHADOW_HEIGHT, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 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);
glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, DepthMap, 0);
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
Then I proceed to setup the geometry
glGenVertexArrays(1, &shadowVertexAttribute);
glBindVertexArray(shadowVertexAttribute);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glEnableVertexAttribArray(2);
//Texture Map
glUniform1i(glGetUniformLocation(sShaderProgram, "DepthMap"), 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, DepthMap);
//Normal Map
glUniform1i(glGetUniformLocation(sShaderProgram, "DiffuseMap"), 1);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, textureMap);
glUniform3fv(glGetUniformLocation(sShaderProgram, "lightPos"), 1, glm::value_ptr(lightPos));
GLuint shadowVertBuffer;
GLuint shadowUVBuffer;
GLuint shadowNormalBuffer;
for (int i = 0; i < objmesh.size(); i++) {
glGenBuffers(1, &shadowVertBuffer);
glBindBuffer(GL_ARRAY_BUFFER, shadowVertBuffer);
glBufferData(GL_ARRAY_BUFFER, objmesh[i]->vertices.size() * sizeof(glm::vec3), &objmesh[i]->vertices[0], GL_STATIC_DRAW);
GLuint svertexPos = glGetAttribLocation(sShaderProgram, "vertex_position");
glVertexAttribPointer(svertexPos, 3, GL_FLOAT, GL_FALSE, 0, (void*)0);
glGenBuffers(1, &shadowUVBuffer);
glBindBuffer(GL_ARRAY_BUFFER, shadowUVBuffer);
glBufferData(GL_ARRAY_BUFFER, objmesh[i]->uvs.size() * sizeof(glm::vec2), &objmesh[i]->uvs[0], GL_STATIC_DRAW);
GLuint svertexUV = glGetAttribLocation(sShaderProgram, "vertex_UV");
glVertexAttribPointer(svertexUV, 2, GL_FLOAT, GL_FALSE, 0, (void*)0);
glGenBuffers(1, &shadowNormalBuffer);
glBindBuffer(GL_ARRAY_BUFFER, shadowNormalBuffer);
glBufferData(GL_ARRAY_BUFFER, objmesh[i]->normals.size() * sizeof(glm::vec3), &objmesh[i]->normals[0], GL_STATIC_DRAW);
GLuint svertexNormal = glGetAttribLocation(sShaderProgram, "vertex_normal");
glVertexAttribPointer(svertexNormal, 3, GL_FLOAT, GL_FALSE, 0, (void*)0);
}
Finally, I render the shadows (or at least try):
if (shadows == true) {
glUseProgram(sShaderProgram);
glBindVertexArray(shadowVertexAttribute);
glm::mat4 lightProjection = glm::ortho(-3000.0f, 3000.0f, -3000.0f,
3000.0f, NEARPLANE, FARPLANE);
glm::mat4 lightView = glm::lookAt(lightPos, glm::vec3(0.0),
glm::vec3(0.0, 1.0, 0.0));
glm::mat4 lightSpaceMatrix = lightProjection * lightView;
glUniformMatrix4fv(glGetUniformLocation(sShaderProgram, "lightSpaceMatrix"),
1, GL_FALSE, glm::value_ptr(lightSpaceMatrix));
glUniformMatrix4fv(glGetUniformLocation(sShaderProgram, "modelMatrix"),
1, GL_FALSE, glm::value_ptr(mesh.modelMatrix));
//rendering to depthmap
glViewport(0, 0, SHADOW_WIDTH, SHADOW_HEIGHT);
glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer);
glClear(GL_DEPTH_BUFFER_BIT);
GLuint texLocation = glGetUniformLocation(sShaderProgram, "DepthMap");
glUniform1i(texLocation, 0);
texLocation = glGetUniformLocation(sShaderProgram, "DiffuseMap");
glUniform1i(texLocation, 1);
glActiveTexture(GL_TEXTURE0 + 0);
glBindTexture(GL_TEXTURE_2D, DepthMap);
glActiveTexture(GL_TEXTURE0 + 1);
glBindTexture(GL_TEXTURE_2D, textureMap);
glDrawArrays(GL_TRIANGLES, 0, mesh.vertices.size());
glBindFramebuffer(GL_FRAMEBUFFER, 0);
setViewPort();
}
Here's also the Shadow Vertex and Shadow Fragment shader if needed.
Vertex:
//Vertex Shader
#version 440
layout(location = 0) in vec3 vertex_position;
layout(location = 1) in vec2 vertex_UV;
layout(location = 2) in vec3 vertex_normal;
uniform mat4 modelMatrix;
uniform mat4 lightSpaceMatrix;
out vec3 outVertex;
out vec2 outTexCoords;
out vec3 outNormals;
out vec4 outVertexLightSpace;
layout(binding = 3 , std140) uniform uniformBlock
{
vec3 camPos;
mat4 world;
mat4 LookAt;
mat4 projection;
mat4 MVP;
};
layout(binding = 4 , std140) uniform materials
{
vec3 Diffuse;
vec3 Ambient;
vec3 Translucency;
//char texturePath[128];
float refraction;
vec3 Specular;
float PhongSpecular;
};
void main()
{
outVertex = vec3(modelMatrix * vec4(vertex_position, 1.0));
outTexCoords = vertex_UV;
outNormals = transpose(inverse(mat3(modelMatrix))) * vertex_normal;
outVertexLightSpace = lightSpaceMatrix * vec4(vertex_position, 1.0f);
gl_Position = projection * LookAt * modelMatrix * vec4(vertex_position ,
1.0);
}
Fragment:
//Fragment Shader
#version 440
out vec4 fragment_color;
uniform sampler2D DepthMap;
uniform sampler2D DiffuseMap;
uniform vec3 lightPos;
in vec3 outVertex;
in vec2 outTexCoords;
in vec3 outNormals;
in vec4 outVertexLightSpace;
layout(binding = 3 , std140) uniform uniformBlock
{
vec3 camPos;
mat4 world;
mat4 LookAt;
mat4 projection;
mat4 MVP;
};
float CalculateShadow(vec4 fragPos){
vec3 projCoords = outVertexLightSpace.xyz / outVertexLightSpace.w;
projCoords = projCoords * 0.5 + 0.5;
float closestDepth = texture(DepthMap, projCoords.xy).r;
float currentDepth = projCoords.z;
float shadow;
if(currentDepth > closestDepth) {
shadow = 1.0;
}
else {
shadow = 0.0;
}
return shadow;
}
void main()
{
vec3 color = texture(DiffuseMap, outTexCoords).rgb;
vec3 normal = normalize(outNormals);
vec3 lightColor = vec3(1.0);
vec3 ambient = 0.4 * color;
vec3 lightDir = normalize(lightPos - outVertex);
float diff = max(dot(lightDir, normal), 0.0);
vec3 diffuse = diff * lightColor;
vec3 viewDir = normalize(camPos - outVertex);
vec3 halfWayDir = normalize(lightDir + viewDir);
float spec = pow(max(dot(normal, halfWayDir), 0.0), 64.0);
vec3 specular = spec * lightColor;
float shadowValue = CalculateShadow(outVertexLightSpace);
vec3 lighting = (ambient + (1.0 - shadowValue) * (diffuse + specular)) * color;
fragment_color = vec4(lighting, 1.0);
}
If you have any pointers to what could be wrong I'd be happy to hear them. Thank you for all your help in advance :D
I made an application which renders skybox and particles over it. I want to add some effects and i need to use framebuffers to render skybox, particles color, depth and position to separate textures. Then i want to use simple shader to use values from these textures and mix them in a proper way. I wrote helper classes for textures, framebuffers and screen quad (simple rectangle to render) but unfortunately - nothing renders when i try to use it.
When binding framebuffers is commented out, my scene looks like this:
Modifying shader shows that depth and position values are calculated properly. Therefore problem lays in texture and framebuffers way of using. Time for some code:
Framebuffer helper class (only important methods):
void Framebuffer::init(){
// unbind all textures from openGL
glBindTexture(GL_TEXTURE_2D, 0);
glGenFramebuffers(1, &framebuffer);
}
void Framebuffer::bind(){
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
}
void Framebuffer::unbind(){
glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
void Framebuffer::attachTexture(GLuint texture, GLenum attachmentType){
glBindTexture(GL_TEXTURE_2D, texture);
glFramebufferTexture(GL_FRAMEBUFFER, attachmentType, texture, 0);
}
void Framebuffer::drawBuffers(GLsizei n, const GLenum *buffers){
glDrawBuffers(n, buffers);
}
Texture helper class:
void Texture::init(GLuint windowWidth, GLuint windowHeight, GLint internalFormat, GLenum format, GLenum type){
glActiveTexture(GL_TEXTURE0);
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D( GL_TEXTURE_2D, 0, internalFormat , windowWidth, windowHeight, 0, format, type, 0);
glBindTexture(GL_TEXTURE_2D, 0);
}
void Texture::bind(){
glBindTexture(GL_TEXTURE_2D, texture);
}
void Texture::unbind(){
glBindTexture(GL_TEXTURE_2D, 0);
}
GLuint Texture::getId(){
return texture;
}
ScreenQuad class:
void ScreenQuad::init(void){
vao.createVAO();
vao.bindVAO();
vbo.createVBO();
vbo.addData(vertices, 8*sizeof(GLfloat));
vbo.bindVBO(GL_ARRAY_BUFFER);
vbo.uploadDataToGPU(GL_STATIC_DRAW);
glVertexAttribPointer((GLuint)3, 2, GL_FLOAT, GL_FALSE, 0, NULL);
loadShaders("shaders/basicPostShader.vp", "shaders/basicPostShader.fp");
}
void ScreenQuad::loadShaders(string vsPath, string fsPath){
shaderProgram.createProgram();
shaderProgram.loadVertexShader(vsPath);
shaderProgram.loadFragmentShader(fsPath);
glBindAttribLocation(shaderProgram.getProgramID(), 3, "v_coord");
shaderProgram.linkProgram();
}
void ScreenQuad::draw(GLuint depthTexture, GLuint colorTexture, GLuint positionTexture, GLuint backgroundTexture){
shaderProgram.bindProgram();
glEnable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, depthTexture);
shaderProgram.setUniform("u_depthtex", 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, colorTexture);
shaderProgram.setUniform("u_colortex", 1);
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_2D, positionTexture);
shaderProgram.setUniform("u_positiontex", 2);
glActiveTexture(GL_TEXTURE3);
glBindTexture(GL_TEXTURE_2D, backgroundTexture);
shaderProgram.setUniform("u_backgroundtex", 3);
glEnableVertexAttribArray(3);
vbo.bindVBO();
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
vbo.unbindVBO();
glDisableVertexAttribArray(3);
shaderProgram.unbindProgram();
}
and methods for initialization and rendering scene:
void OpenGLContext::setupScene(void) {
glClearColor(0.4f, 0.6f, 0.9f, 1.0f);
//FRAMEBUFFERS:
skyboxFramebuffer.init();
skyboxTexture.init(windowWidth, windowHeight, GL_RGBA32F, GL_RGBA, GL_FLOAT);
skyboxFramebuffer.bind();
skyboxFramebuffer.attachTexture(skyboxTexture.getId(), GL_COLOR_ATTACHMENT0);
const GLenum skyboxDrawBuffers[1] = { GL_COLOR_ATTACHMENT0};
skyboxFramebuffer.drawBuffers(1, skyboxDrawBuffers);
skyboxFramebuffer.validate();
skyboxFramebuffer.unbind();
mainFramebuffer.init();
mainColorTexture.init(windowWidth, windowHeight, GL_RGBA32F, GL_RGBA, GL_FLOAT);
mainPositionTexture.init(windowWidth, windowHeight, GL_RGBA32F, GL_RGBA, GL_FLOAT);
mainDepthTexture.init(windowWidth, windowHeight, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT, GL_FLOAT);
mainFramebuffer.bind();
mainFramebuffer.attachTexture(mainColorTexture.getId(), GL_COLOR_ATTACHMENT0);
mainFramebuffer.attachTexture(mainPositionTexture.getId(), GL_COLOR_ATTACHMENT1);
mainFramebuffer.attachTexture(mainDepthTexture.getId(), GL_DEPTH_ATTACHMENT);
const GLenum mainDrawBuffers[2] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
mainFramebuffer.drawBuffers(2, mainDrawBuffers);
mainFramebuffer.validate();
mainFramebuffer.unbind();
//SKYBOX:
skybox->init("resources/skybox/default/",
"pos_x.tga",
"neg_x.tga",
"pos_y.tga",
"neg_y.tga",
"pos_z.tga",
"neg_z.tga");
//PARTICLES:
particles->init(scene);
//SCREENQUAD:
screenQuad.init();
}
void OpenGLContext::renderScene() {
glfwGetFramebufferSize(window, &windowWidth, &windowHeight);
glViewport(0, 0, windowWidth, windowHeight);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
fpsCounter->calcFPS(1.0, windowName);
if(mode==INPUT_ENABLED_MODE){
updateInputs();
}
projectionMatrix = controls->getProjectionMatrix();
viewMatrix = controls->getViewMatrix();
modelMatrix = glm::mat4(1.0f);
glm::mat4 mvpMatrix = projectionMatrix*viewMatrix*modelMatrix;
//SKYBOX:
skyboxFramebuffer.bind();
skybox->render(mvpMatrix);
skyboxFramebuffer.unbind();
//PARTICLES:
if(scene->tryLockScene()){
if(scene->isSceneUpdated()){
particles->updateParticlesPosition(scene);
scene->setSceneUpdated(false);
}
scene->unlockScene();
}
mainFramebuffer.bind();
particles->draw(modelMatrix, viewMatrix, projectionMatrix);
mainFramebuffer.unbind();
//SCREENQUAD:
screenQuad.draw(mainDepthTexture.getId(), mainColorTexture.getId(), mainPositionTexture.getId(), skyboxTexture.getId());
glfwSwapBuffers(window);
glfwPollEvents();
}
plus screenQuad shaders:
vertex:
#version 430
layout (location = 3) in vec2 v_coord;
layout (binding = 0) uniform sampler2D u_depthtex;
layout (binding = 1) uniform sampler2D u_colortex;
layout (binding = 2) uniform sampler2D u_positiontex;
layout (binding = 3) uniform sampler2D u_backgroundtex;
out vec2 fs_texcoord;
void main(void) {
gl_Position = vec4(v_coord, 0.0, 1.0);
fs_texcoord = (v_coord + 1.0) / 2.0;
}
and fragment:
#version 430
layout (binding = 0) uniform sampler2D u_depthtex;
layout (binding = 1) uniform sampler2D u_colortex;
layout (binding = 2) uniform sampler2D u_positiontex;
layout (binding = 3) uniform sampler2D u_backgroundtex;
layout (location = 0) out vec4 out_Color;
in vec2 fs_texcoord;
void main(void) {
float exp_depth = texture(u_depthtex,fs_texcoord).r;
if(exp_depth>0.99f){
out_Color = vec4(texture(u_backgroundtex,fs_texcoord).xyz,1.0f);
return;
}
out_Color = vec4(texture(u_colortex,fs_texcoord).xyz, 1.0f);
}
Shader helper classes, vao and vbo helper classes are fine for sure. No errors occurs in logs.
UPDATE:
particles vertex shader:
#version 430
uniform mat4x4 modelViewMatrix;
uniform mat4x4 projectionMatrix;
uniform float pointRadius; // point size in world space
uniform float pointScale; // scale to calculate size in pixels
layout (location = 0) in vec3 in_Position;
layout (location = 1) in vec4 in_Color;
out vec3 fs_PosEye;
out vec4 fs_Position;
out vec4 fs_Color;
void main(void) {
vec3 posEye = (modelViewMatrix * vec4(in_Position.xyz, 1.0f)).xyz;
float dist = length(posEye);
gl_PointSize = pointRadius * (pointScale/dist);
fs_PosEye = posEye;
fs_Position = modelViewMatrix * vec4(in_Position.xyz, 1.0f);
fs_Color = in_Color;
gl_Position = projectionMatrix * modelViewMatrix * vec4(in_Position.xyz, 1.0f);
}
fragment shader:
#version 430
uniform mat4x4 modelViewMatrix;
uniform mat4x4 projectionMatrix;
uniform float pointRadius; // point size in world space
uniform float pointScale; // scale to calculate size in pixels
in vec4 fs_Position;
in vec3 fs_PosEye;
in vec4 fs_Color;
layout (location = 0) out vec4 out_Color;
layout (location = 1) out vec4 out_Position;
void main(void)
{
// calculate normal from texture coordinates
vec3 normal;
normal.xy = gl_PointCoord.xy*vec2(2.0, -2.0) + vec2(-1.0, 1.0);
float r = dot(normal.xy, normal.xy);
if(r>1.0)
discard;
normal.z = sqrt(1.0-r);
//calculate depth
vec4 pixelPos = vec4(fs_PosEye + normalize(normal)*pointRadius,1.0f);
vec4 clipSpacePos = projectionMatrix * pixelPos;
gl_FragDepth = (clipSpacePos.z / clipSpacePos.w);
out_Color = fs_Color;
out_Position = pixelPos;
}
and Particles.draw() method:
void CParticles::draw(glm::mat4 modelMatrix, glm::mat4 viewMatrix, glm::mat4 projectionMatrix){
shaderProgram.bindProgram();
glm::mat4 modelViewMatrix = viewMatrix*modelMatrix;
shaderProgram.setUniform("projectionMatrix", &projectionMatrix);
shaderProgram.setUniform("modelViewMatrix", &modelViewMatrix);
shaderProgram.setUniform("pointRadius", &pointRadius);
shaderProgram.setUniform("pointScale", &pointScale);
glPointParameteri(GL_POINT_SPRITE_COORD_ORIGIN, GL_LOWER_LEFT);
glEnable(GL_POINT_SPRITE);
glEnable(GL_PROGRAM_POINT_SIZE);
glDepthMask(GL_TRUE);
glEnable(GL_DEPTH_TEST);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glDrawArrays(GL_POINTS, 0, n);
glDisableVertexAttribArray(0);
glDisableVertexAttribArray(1);
glDisable(GL_PROGRAM_POINT_SIZE);
glDisable(GL_POINT_SPRITE);
shaderProgram.unbindProgram();
}
UPDATE2:
The problem is that textures filled by a particle shader are empty when I try to sample data from them in a screenQuad shader. Each depth, position and color texture samplers return zeros. I use same classes and same methods as with a skybox, but skybox texture works fine.
UPDATE3:
Random code changes showed me that if I comment line with attaching depth texture to framebuffer, particle color is finally passed to a texture and i can see it on a screen quad (but without any depth test. Red particles (drawed last) are always on the front).
I guess there is a problem with connecting particle shader with depth texture. But still I can't find an exact bug. I hope my sugestion will be helpful.
I haven't studied the entire code, but one problem jumps out immediately:
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, colorTexture);
shaderProgram.setUniform("u_colortex", colorTexture);
The value of a uniform for a texture sampler is not the texture id (aka name). It's the texture unit the texture is bound to. So in this case, since you're using texture unit 1 for this texture, it should be:
shaderProgram.setUniform("u_colortex", 1);
The problem was that glDepthMask() was disabled when i invoked glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);.
It needs to be enabled in order to glClear(GL_DEPTH_BUFFER_BIT) took any effect.
Plus I needed to add cleaning framebuffers in a proper way as well.
I'm trying out my hand at graphics, following a tutorial at http://en.wikibooks.org/wiki/OpenGL_Programming/Modern_OpenGL_Tutorial_06
Problem: When I try to texture my cube, my sample is black.
Screenshot: http://puu.sh/2JP1H.jpg (note: I set blue = uv.x to test my UVs)
I looked at the threads OpenGL textures appear just black, and
Texture is all black, but it seemed they had different problems.
First I load my texture using SOIL image loading library:
int w, h;
unsigned char* img = SOIL_load_image("resources/images/4x4window.jpg",&w,&h,0,0);
ErrorIf(!img, "%s", SOIL_last_result());
glGenTextures(1, &texture_id);
glBindTexture(GL_TEXTURE, texture_id);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,w,h,0,GL_RGB,GL_UNSIGNED_BYTE,img);
My render function where I pass my texture to the shader program:
void onDisplay()
{
glClearColor(1.0, 1.0, 1.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(program);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture_id);
glUniform1i(uniform_myTexture, /*GL_TEXTURE*/0);
glEnableVertexAttribArray(attribute_coord3d); // open shader var
glBindBuffer(GL_ARRAY_BUFFER, vbo_cube_verts); // put stuff in buffer
glVertexAttribPointer(attribute_coord3d, 3, GL_FLOAT, GL_FALSE, 0, 0); //send
glEnableVertexAttribArray(attribute_texcoord);
glBindBuffer(GL_ARRAY_BUFFER, vbo_cube_texcoords);
glVertexAttribPointer(attribute_texcoord, 2, GL_FLOAT, GL_FALSE, 0, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_cube_elements);
int size;
glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
glDrawElements(GL_TRIANGLES, size / sizeof(GLushort), GL_UNSIGNED_SHORT, 0);
glDisableVertexAttribArray(attribute_coord3d);
glDisableVertexAttribArray(attribute_texcoord);
glutSwapBuffers();
}
Vertex Shader:
attribute vec3 coord3d;
attribute vec2 texcoord;
varying vec2 f_texcoord;
uniform mat4 mvp;
void main(void)
{
gl_Position = mvp * vec4(coord3d, 1.0);
f_texcoord = texcoord;
}
Fragment Shader:
varying vec2 f_texcoord;
uniform sampler2D mytexture;
void main(void)
{
vec4 result = texture2D(mytexture, f_texcoord);
result.z = f_texcoord.x;
result.w = 1;
gl_FragColor = result;
}
The line where the the texture is bound is:
glBindTexture(GL_TEXTURE, texture_id);
that should be:
glBindTexture(GL_TEXTURE_2D, texture_id);