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I try to render a big block of individual cubes in OpenGL and i'm now experimenting with lighting.
It works quite good, but when viewing the cube from a certain angle, its shows highlights with shouldn't be there.
I altered the shader so the specular highlights are red.
I just expected them to not be there because the light comes from the direction with the all bright cubes and there should be no reflections from this lightsource on the side of the cube.
Another thing which bothers me is, that there is an edge(Pic 2) where color changes. This is also something i don't quite understand and seek help with.
This is present when I use a directional lightsource and view the big cube from a certain angle.
OpenGl Version ist 3.3, i'm on Windows and using c++ with cmake to build.
Here are some images:
Github Link, because SOT does not allow me to upload code becaues "it is not formatted"(trying like 20 min to format them to SOT likes).
Edit: It works now, who could have thought that it was the formatting of the images and not actually the cpp, glsl code.
Github
Important Files: light_proto.glsl, vertex.glsl, main.cpp
Files
main.cpp
// RENDER LOOP
while (!glfwWindowShouldClose(window))
{
// INPUT
//keysboard input, mouse input
processInput(window);
defaultShader.use();
// CAMERA
// model matrix set further down, dynamically for each object
//view matrix, transform world space to camera space
glm::mat4 view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);
defaultShader.setMatrix4fv("view", view);
//projection matrix, view space to device cordinates
glm::mat4 projection = glm::perspective(glm::radians(fov), 800.0f / 600.0f, 0.1f, 100.0f);
defaultShader.setMatrix4fv("projection", projection);
// DRAWING
//clear color and depth buffer
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
////vertex data, shaders
cube->use();
defaultShader.setVec3("viewPos", cameraPos.x, cameraPos.y, cameraPos.z);
defaultShader.setVec3("material.specular", 0.0f, 1.0f, 0.0f);
defaultShader.setFloat("material.shininess", 32.0f);
defaultShader.setVec3("dirLight.direction", -1.0f, -0.0f, 0.0f);
defaultShader.setVec3("dirLight.ambient", 0.2f, 0.2f, 0.2f);
defaultShader.setVec3("dirLight.diffuse", 0.8f, 0.8f, 0.8f); // darken diffuse light a bit
defaultShader.setVec3("dirLight.specular", 1.0f, 1.0f, 1.0f);
defaultShader.setVec3("pointLights[0].position", -1.0f, -1.0f, -1.0f);
defaultShader.setVec3("pointLights[0].ambient", 0.2f, 0.2f, 0.2f);
defaultShader.setVec3("pointLights[0].diffuse", 0.8f, 0.8f, 0.8f); // darken diffuse light a bit
defaultShader.setVec3("pointLights[0].specular", 1.0f, 1.0f, 1.0f);
defaultShader.setFloat("pointLights[0].constant", 1.0f);
defaultShader.setFloat("pointLights[0].linear", 0.045f);
defaultShader.setFloat("pointLights[0].quadratic", 0.0075f);
//defaultShader.setVec3("lightColor", 1.0f, 1.0f, 1.0f);
//defaultShader.setVec3("lightPos", -1.0f, lighty, -1.0f);
//defaultShader.setVec3("viewPos", cameraPos.x, cameraPos.y, cameraPos.z);
//defaultShader.setVec3("material.specular", 0.0f, 1.0f, 0.0f);
//defaultShader.setFloat("material.shininess", 128.0f);
//defaultShader.setVec3("light.direction", -10.0f, lighty, 10.0f);
//defaultShader.setBool("light.isDirectional", false);
//defaultShader.setVec3("light.ambient", 0.2f, 0.2f, 0.2f);
//defaultShader.setVec3("light.diffuse", 0.8f, 0.8f, 0.8f); // darken diffuse light a bit
//defaultShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f);
//defaultShader.setFloat("light.constant", 1.0f);
//defaultShader.setFloat("light.linear", 0.045f);
//defaultShader.setFloat("light.quadratic", 0.0075f);
int cubesize = 30;
//draw cubes
for (float i = 0.0f; i < cubesize; i++) {
for (float j = 0.0f; j < cubesize; j++) {
for (float k = 0.0f; k < cubesize; k++) {
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(i, j, k));
defaultShader.setMatrix4fv("model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
}
}
}
//DRAW LIGHT
light->use();
lightshader.use();
lightshader.setMatrix4fv("view", view);
lightshader.setMatrix4fv("projection", projection);
glm::mat4 model = glm::mat4(1.0f);
lighty += 0.1f * deltaTime;
model = glm::translate(model, glm::vec3(-1.0, -1.0, -1.0));
lightshader.setMatrix4fv("model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
//GLFW updating the window
glfwSwapBuffers(window);
glfwPollEvents();
}
Fragment Shader
#version 330 core
in vec2 TexCoord;
in vec3 Normal;
in vec3 FragPos;
struct DirLight {
vec3 direction;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
uniform DirLight dirLight;
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir);
struct PointLight {
vec3 position;
float constant;
float linear;
float quadratic;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
#define NR_POINT_LIGHTS 1
uniform PointLight pointLights[NR_POINT_LIGHTS];
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
struct Material {
vec3 specular;
float shininess;
};
uniform Material material;
uniform sampler2D texture0;
uniform vec3 viewPos;
out vec4 FragColor;
void main()
{
// properties
vec3 norm = normalize(Normal);
vec3 viewDir = normalize(viewPos - FragPos);
// phase 1: Directional lighting
vec3 result = CalcDirLight(dirLight, norm, viewDir);
// phase 2: Point lights
for(int i = 0; i < NR_POINT_LIGHTS; i++)
//result += CalcPointLight(pointLights[i], norm, FragPos, viewDir);
FragColor = texture2D(texture0, TexCoord) * vec4(result, 1.0);
}
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
{
vec3 lightDir = normalize(-light.direction);
// diffuse shading
float diff = max(dot(normal, lightDir), 0.0);
// specular shading
vec3 reflectDir = reflect(-lightDir, normal);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
// combine results
vec3 ambient = light.ambient * vec3(texture(texture0, TexCoord));
vec3 diffuse = light.diffuse * diff * vec3(texture(texture0, TexCoord));
vec3 specular = light.specular * spec * vec3(1.0f, 0.0f, 0.0f);
return (ambient + diffuse + specular);
}
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
{
vec3 lightDir = normalize(light.position - fragPos);
// diffuse shading
float diff = max(dot(normal, lightDir), 0.0);
// specular shading
vec3 reflectDir = reflect(-lightDir, normal);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
// attenuation
float distance = length(light.position - fragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance +
light.quadratic * (distance * distance));
// combine results
vec3 ambient = light.ambient * vec3(texture(texture0, TexCoord));
vec3 diffuse = light.diffuse * diff * vec3(texture(texture0, TexCoord));
vec3 specular = light.specular * spec * vec3(1.0f, 1.0f, 1.0f);
ambient *= attenuation;
diffuse *= attenuation;
specular *= attenuation;
return (ambient + diffuse + specular);
}
Vertex Shader
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTexCoord;
layout (location = 2) in vec3 aNormal;
out vec2 TexCoord;
out vec3 Normal;
out vec3 FragPos;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main(){
gl_Position = projection * view * model * vec4(aPos, 1.0f);
FragPos = vec3(model * vec4(aPos, 1.0));
TexCoord = vec2(aTexCoord.x, aTexCoord.y);
Normal = aNormal;
};
It looks like you have one issue and a half
First in image 2 (and 3) the reason why there is a line in the diamond texture is due to texture filtering.
I checked your source code in Texture.cpp the Minification filter is set to GL_NEAREST_MIPMAP_NEAREST and you also generate the relative mipsmaps.
If you change
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
to
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
at line 23 of Texture.cpp and remove
glGenerateMipmap(GL_TEXTURE_2D);
the line should disapper
I do not understand where the problem stands with the red specular light, if you could show the source of the light direction i think might be able to help
I have this code but the light seems not working correctly, when I render the object it's dark, then when I rotate it, the light source seems to be rotated too. I can't figure out where the problem is. I tried to modify the model for the light but still not working
this is the program:
while (!glfwWindowShouldClose(window))
{
/* Render here */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glm::mat4 view = glm::mat4(1.0f);
glm::mat4 projection = glm::mat4(1.0f);
projection = glm::perspective(glm::radians(45.0f), (float)width / (float)heigh, 0.1f, 100.0f);
view = glm::translate(view, glm::vec3(0.0f, 0.0f, transZ)); //this is for scroll mouse
view = glm::translate(view, glm::vec3(0.0f, 0.0f, -2.0f));
view = glm::translate(view, glm::vec3(0.0f, 0.0f, -5.0f));
glUseProgram(programT);
int lightColorLoc = glGetUniformLocation(programT, "lightColor");
glUniformMatrix4fv(lightColorLoc, 1, GL_FALSE, glm::value_ptr(glm::vec3(1.0f, 0.0f, 0.0f)));
int objectColorLoc = glGetUniformLocation(programT, "objectColor");
glUniformMatrix4fv(objectColorLoc, 1, GL_FALSE, glm::value_ptr(glm::vec3(1.0f, 0.5f, 0.31f)));
glm::vec3 lightPos(2.0f, 4.0f, 5.0f);
int lightPosLoc = glGetUniformLocation(programT, "lightPos");
glUniformMatrix4fv(lightPosLoc, 1, GL_FALSE, glm::value_ptr(lightPos));
int projectionLocLight = glGetUniformLocation(programT, "projection");
glUniformMatrix4fv(projectionLocLight, 1, GL_FALSE, glm::value_ptr(projection));
glm::mat4 modelLight = glm::mat4(1.0f);
int modelLocLight = glGetUniformLocation(programT, "model");
glUniformMatrix4fv(modelLocLight, 1, GL_FALSE, glm::value_ptr(modelLight));
glm::mat4 viewLight = glm::mat4(1.0f);
int viewLocLight = glGetUniformLocation(programT, "view");
glUniformMatrix4fv(viewLocLight, 1, GL_FALSE, glm::value_ptr(viewLight));
int viewLoc = glGetUniformLocation(programT, "view");
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
int projectionLoc = glGetUniformLocation(programT, "projection");
glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, glm::value_ptr(projection));
model = glm::rotate(model, glm::radians(rotX), glm::vec3(1.0f, 0.0f, 0.0f));
model = glm::rotate(model, glm::radians(rotY), glm::vec3(.0f, 1.0f, .0f));
model = glm::rotate(model, glm::radians(rotZ), glm::vec3(.0f, 0.0f, 1.0f));
int modelLoc = glGetUniformLocation(programT, "model");
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
glGenerateMipmap(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, textureArray[0]);
glUniform1i(glGetUniformLocation(programT, "ourTexture"), 0);
glBindVertexArray(VAOArray[0]);
glDrawArrays(GL_TRIANGLES, 0, myMeshes.at(0).Indices.size());
/* Swap front and back buffers */
glfwSwapBuffers(window);
/* Poll for and process events */
glfwPollEvents();
glfwSetKeyCallback(window, key_callback);
glfwSetScrollCallback(window, scroll_callback);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
}
the following is my vertex shader:
#version 330 core
layout (location = 0) in vec3 RealPos;
layout (location = 1) in vec3 vertex_color;
layout (location = 2) in vec2 vertex_textcoord;
layout (location = 3) in vec3 RealNor;
out vec3 vs_pos;
out vec3 vs_color;
out vec2 vs_text;
out vec3 normal;
out vec3 FragPos;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
vs_pos = RealPos;
vs_color = vertex_color;
vs_text=vertex_textcoord;
normal=RealNor;
FragPos = vec3(model * vec4(vs_pos, 1.0));
gl_Position = projection * view * model * vec4(vs_pos, 1.0);
}
and the following is the fragment shader:
#version 330 core
in vec2 vs_text;
in vec3 normal;
in vec3 FragPos;
uniform vec3 lightPos;
out vec4 gl_FragColor;
uniform vec3 objectColor;
uniform vec3 lightColor;
uniform sampler2D ourTexture;
void main()
{
vec3 norm = normalize(normal);
vec3 lightDir = normalize(lightPos - FragPos);
float ambientStrength = 0.1;
vec3 ambient = ambientStrength * lightColor;
float diff = max(dot(norm, lightDir), 0.0);
vec3 diffuse = diff * lightColor;
vec3 result = (ambient + diffuse) * objectColor;
gl_FragColor = texture(ourTexture, vs_text) * vec4(result,1.0);
}
how can I solve the problem?
The light calculations in the fragment shader are done in world space. Therefore, you have to transform the normal vector with the normal matrix from object space to world space:
mat3 normalMatrix = transpose(inverse(mat3(model)));
normal = normalMatrix * RealNor;
FragPos = vec3(model * vec4(vs_pos, 1.0));
See Why is the transposed inverse of the model view matrix used to transform the normal vectors?
and Why transforming normals with the transpose of the inverse of the modelview matrix?
Imagine a spinner and a reading lamp on a table. Your eyes are the camera. The model matrix models the spinning. This causes different sides of the spinner to be illuminated as it rotates. However, the position of the lamp does not change relative to your position.
The relative position of the lamp changes when you change your position (the position of the eyes). This can be modeled by changing the view matrix.
I am trying to build lighting using this tutorial. However, lighting appears on wrong side of human object and I do not know why.
Normals were created per triangle. Vertices of a triangle basically have the same normal:
glm::vec3 calculateNormal(glm::vec3 vertice_1, glm::vec3 vertice_2, glm::vec3 vertice_3)
{
glm::vec3 vector_1 = vertice_2 - vertice_1;
glm::vec3 vector_2 = vertice_3 - vertice_1;
return glm::normalize(glm::cross(vector_1, vector_2));
}
Here is code for vertex shader:
#version 330 core
layout (location = 0) in vec3 pos;
layout (location = 1) in vec3 normal;
out vec4 vert_color;
out vec3 Normal;
out vec3 FragPos;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
uniform mat4 transform;
uniform vec4 color;
void main()
{
vert_color = color;
gl_Position = projection * view * model * transform * vec4(pos.x, pos.y, pos.z, 1.0);
FragPos = vec3(model * transform * vec4(pos, 1.0));
Normal = normal;
}
Fragment shader:
#version 330 core
uniform vec3 cameraPos;
uniform vec3 lightPos;
uniform vec3 lightColor;
in vec4 vert_color;
in vec3 FragPos;
in vec3 Normal;
out vec4 frag_color;
void main()
{
float ambientStrength = 0.1;
float specularStrength = 0.5;
vec3 ambient = ambientStrength * lightColor;
vec3 lightDir = normalize(lightPos - FragPos);
float diff = max(dot(Normal, lightDir), 0.0);
vec3 diffuse = diff * lightColor;
vec3 viewDir = normalize(cameraPos - FragPos);
vec3 reflectDir = reflect(-lightDir, Normal);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
vec3 specular = specularStrength * spec * lightColor;
vec3 result = (ambient + diffuse + specular) * vec3(vert_color.x, vert_color.y, vert_color.z);
frag_color = vec4(result, vert_color.w);
}
Main loop:
wxGLCanvas::SetCurrent(*glContext);
glClearDepth(1.0f);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDepthFunc(GL_LEQUAL);
glEnable(GL_DEPTH_TEST);
glm::mat4 model, view, projection;
model = glm::translate(model, modelPos); // modelPos is
view = fpsCamera->getViewMatrix();
projection = fpsCamera->getProjectionMatrix(windowWidth, windowHeight);
color = glm::vec4(0.310f, 0.747f, 0.185f, 1.0f);
glm::vec3 lightPos = glm::vec3(0.0f, 1.0f, 0.0f);
glm::vec3 lightColor = glm::vec3(1.0f, 1.0f, 1.0f);
glm::mat4 phantomtTransformation;
phantomtTransformation = glm::rotate(phantomtTransformation, - glm::pi<float>() / 2.0f, glm::vec3(1.0f, 0.0f, 0.0f));
phantomtTransformation = glm::rotate(phantomtTransformation, - glm::pi<float>() , glm::vec3(0.0f, 0.0f, 1.0f));
ShaderProgram shaderProgram;
shaderProgram.loadShaders("Shaders/phantom.vert", "Shaders/phantom.frag");
glClearStencil(0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
shaderProgram.use();
shaderProgram.setUniform("transform", phantomtTransformation);
shaderProgram.setUniform("model", model);
shaderProgram.setUniform("view", view);
shaderProgram.setUniform("projection", projection);
shaderProgram.setUniform("color", color);
shaderProgram.setUniform("lightColor", lightColor);
shaderProgram.setUniform("lightPos", lightPos);
shaderProgram.setUniform("cameraPos", fpsCamera->getPosition());
glStencilMask(0xFF); // Write to stencil buffer
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
glStencilFunc(GL_ALWAYS, 0, 0xFF); // Set any stencil to 0
glStencilFunc(GL_ALWAYS, 1, 0xFF); // Set any stencil to object ID
m_pantomMesh->draw();
glStencilFunc(GL_ALWAYS, 0, 0xFF); // Set any stencil to 0 // no need for testing
glFlush();
wxGLCanvas::SwapBuffers();
View from front of the object:
View from back of the object:
EDIT:
In order to debug I removed object rotation matrix from main loop:
glm::mat4 phantomtTransformation;
phantomtTransformation = glm::rotate(phantomtTransformation, - glm::pi<float>() / 2.0f, glm::vec3(1.0f, 0.0f, 0.0f));
phantomtTransformation = glm::rotate(phantomtTransformation, - glm::pi<float>() , glm::vec3(0.0f, 0.0f, 1.0f));
shaderProgram.setUniform("transform", phantomtTransformation);
and changed line in fragment shader from
frag_color = vec4(result, vert_color.w);
to
frag_color = vec4(Normal, vert_color.w);
in order to visualize Normal values. As a result I noticed that when camera changes position phantom also changes color which means that normal values are also changing.
I think the cause of your problem is that you are not applying your model transformation to your normal vectors. Since you definitely do not want to skew them, you will have to create a special matrix for your normals.
As is explained further down the tutorial that you mentioned, the matrix can be constructed like this
Normal = mat3(transpose(inverse(model))) * aNormal;
in your vertex shader.
However, I highly recommend that you calculate the matrix in your application code instead, since you would calculate it per vertex in the above example.
Since you are using the glm library, it would look like this instead:
glm::mat3 model_normal = glm::mat3(glm::transpose(glm::inverse(model)));
You can then load your new model_normal matrix into the shader as a uniform mat3.
For some reason, the quad that I'm rendering doesn't show and it only renders a black screen. I've checked the code multiple times and couldn't find the problem maybe someone can see what I don't see!
The purpose is to have a quad that follows the camera, right now I just want to show the quad with a single color, but all I get is a black screen. I am using QOpenGLWindow and QOpenGLFunctions.
void CSLFWindow::renderQuad()
{
float x0 = -(float)1.f, y0 = -(float)1.f;
float x1 = (float)1.f, y1 = (float)1.f;
const QVector3D vertices[4] = {
QVector3D( x0, y0, 0.0f),
QVector3D( x0, y1, 0.0f),
QVector3D( x1, y1, 0.0f),
QVector3D( x1, y0, 0.0f)
};
const QVector3D normals[4] = {
QVector3D(0.0f, 0.0f,1.0f),
QVector3D(0.0f, 0.0f,1.0f),
QVector3D(0.0f, 0.0f,1.0f),
QVector3D(0.0f, 0.0f,1.0f)
};
const QVector2D texcoords[4] = {
QVector2D(0.0f, 1.0f),
QVector2D(0.0f, 0.0f),
QVector2D(1.0f, 0.0f),
QVector2D(1.0f, 1.0f)
};
const unsigned int indices[4] = { 3, 2, 1, 0 };
m_shaderProgram.enableAttributeArray("vVertices");
m_shaderProgram.enableAttributeArray("vTexCoords");
m_shaderProgram.enableAttributeArray("vNormals");
m_shaderProgram.setAttributeArray("vVertices", vertices);
m_shaderProgram.setAttributeArray("vTexCoords", texcoords);
m_shaderProgram.setAttributeArray("vNormals", normals);
glDrawElements(GL_QUADS, 4, GL_UNSIGNED_INT, indices);
m_shaderProgram.disableAttributeArray("vVertices");
m_shaderProgram.disableAttributeArray("vTexCoords");
m_shaderProgram.disableAttributeArray("vNormals");
}
and the rendering:
void CSLFWindow::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
m_shaderProgram.bind();
m_model.setToIdentity();
m_view = m_camera.toMatrix();
QMatrix4x4 modelMatrix = m_model ;
QMatrix4x4 modelViewMatrix = m_view * modelMatrix;
QMatrix4x4 mvp = m_projection * modelViewMatrix;
m_shaderProgram.setUniformValue("MV", modelViewMatrix);
m_shaderProgram.setUniformValue("MVP", mvp);
m_shaderProgram.setUniformValue("P", m_projection);
renderQuad();
m_shaderProgram.release();
}
I'm setting the projection matrix as:
m_view.setToIdentity();
float aspect = h / w;
m_projection.setToIdentity();
m_projection.perspective(
m_fov,
aspect,
0.1f,
1000.0f);
here are my camera parameters:
m_cameraPos = QVector3D(0.0f, 0.0f, 3.0f);
m_cameraFront = QVector3D(0.0f, 0.0f, -1.0f);
m_cameraUp = QVector3D(0.0f, 1.0f, 0.0f);
QMatrix4x4 toMatrix()
{
QMatrix4x4 vMatrix;
vMatrix.setToIdentity();
vMatrix.lookAt(m_cameraPos, QVector3D(0.0f, 0.0f, 0.0f),
m_cameraUp);
return vMatrix;
}
and here is my vertex shader:
#version 330 core
layout (location = 0)in vec3 vVertices;
layout (location = 1)in vec2 vTexCoords;
layout (location = 2)in vec3 vNormals;
uniform mat4 MV;
uniform mat4 MVP;
uniform mat4 P;
out vec2 FragTexCoord;
out vec3 FragNormals;
void main()
{
FragTexCoord = vTexCoords;
FragNormals = vNormals;
gl_Position = MVP * vec4(vVertices,1);
}
and my fragment shader:
#version 330 core
out vec4 fragmentColor;
in vec2 FragTexCoord;
in vec3 FragNormals;
void main()
{
fragmentColor = vec4(1.0,1.0,1.0,1.0);
}
I found the problem was in setting the surface format! when I remove format.setProfile(QSurfaceFormat::CoreProfile); I see the quad. but I don't understand why it happens
Change GL_QUAD to GL_TRIANGLE_FAN and it will work:
glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_INT, indices);
GL_QUAD is deprecated and is removed in core profile.
See further Legacy OpenGL - Removed functionality, OpenGL Context and Forward compatibility
Hey I cant add a comment but could you try to change vertex shader like this:
void main()
{
FragTexCoord = vTexCoords;
FragNormals = vNormals;
gl_Position = vec4(vVertices,1);
}
and let me know if you see anything if you don't see anything try to change the order of the indices
I'm trying to make a little 3D engine for my master degree (and for my skill). I have a problem on the specular reflection. (I'm sorry for the link for the illustration image but I haven't enough reputation yet). All sources is available on my GitHub : DWRenderer
Right here, we're behing the object but the camera is on the front also the light. As we can see, there's a reflection behind the object.
For describe the actual parameters, all the computations are made in world space (normally... with that problem, I've a doubt). I put the camera on position vec3(0, 0, 3) for the test and the light is just a point at vec3(1.2, 1, 2) represent by a cube. I'm using Qt 5.4 and OpenGL 4.1 under Ubuntu with Nvidia drivers.
Here's my vertex shader :
#version 410 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec3 normal;
out vec3 Normal;
out vec3 FragPos;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
uniform mat3 normalMatrix;
void main()
{
gl_Position = projection * view * model * vec4(position, 1.0f);
FragPos = vec3(model * vec4(position, 1.0f));
Normal = normalMatrix * normal;
}
And my fragment shader:
#version 410 core
out vec4 color;
in vec3 Normal;
in vec3 FragPos;
struct Material {
vec3 ambient;
vec3 diffuse;
vec3 specular;
float shininess;
};
struct Light {
vec3 position;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
uniform Material material;
uniform Light light;
uniform vec3 viewPos;
void main()
{
// Vectors
vec3 norm = normalize(Normal);
vec3 lightDir = normalize(light.position - FragPos);
vec3 viewDir = normalize(viewPos - FragPos);
vec3 reflectDir = reflect(-lightDir, norm);
// Ambient
vec3 ambient = material.ambient * light.ambient;
// Diffuse
float diff = clamp(dot(lightDir, norm), 0.0, 1.0);
vec3 diffuse = diff * material.diffuse * light.diffuse;
// Specular - The bug seems only here
float spec = pow(clamp(dot(viewDir, reflectDir), 0.0, 1.0), material.shininess);
vec3 specular = spec * material.specular * light.specular;
vec3 result = (diffuse + specular + ambient);
color = vec4(result, 1.0f);
// For test vectors
//color = vec4(specular, 1.0f);
}
And the code in the gaming loop (paintGL with a time with an interval of 16ms for real-time) for initialize the uniform variable (The position of the camera for the shader is fixed, i can turn around my cube for check the bug. The position of the light is in "initializeGL" and fixed too) :
// Draw cube
m_cubeShader->useShaderProgram();
GLint lightPosLoc = glGetUniformLocation(m_cubeShader->getId(), "light.position");
GLint viewPosLoc = glGetUniformLocation(m_cubeShader->getId(), "viewPos");
GLint matAmbientLoc = glGetUniformLocation(m_cubeShader->getId(), "material.ambient");
GLint matDiffuseLoc = glGetUniformLocation(m_cubeShader->getId(), "material.diffuse");
GLint matSpecularLoc = glGetUniformLocation(m_cubeShader->getId(), "material.specular");
GLint matShineLoc = glGetUniformLocation(m_cubeShader->getId(), "material.shininess");
GLint lightAmbientLoc = glGetUniformLocation(m_cubeShader->getId(), "light.ambient");
GLint lightDiffuseLoc = glGetUniformLocation(m_cubeShader->getId(), "light.diffuse");
GLint lightSpecularLoc = glGetUniformLocation(m_cubeShader->getId(), "light.specular");
glUniform3f(lightAmbientLoc, 0.2f, 0.2f, 0.2f);
glUniform3f(lightDiffuseLoc, 0.5f, 0.5f, 0.5f);
glUniform3f(lightSpecularLoc, 1.0f, 1.0f, 1.0f);
glUniform3f(matAmbientLoc, 1.0f, 0.5f, 0.31f);
glUniform3f(matDiffuseLoc, 1.0f, 0.5f, 0.31f);
glUniform3f(matSpecularLoc, 0.5f, 0.5f, 0.5f);
glUniform1f(matShineLoc, 32.0f);
glUniform3f(viewPosLoc, 0.0f, 0.0f, 3.0f); // For testing a bug - Unresolved
//glUniform3f(viewPosLoc, m_camera->getPosition().x, m_camera->getPosition().y, m_camera->getPosition().z);
glUniform3f(lightPosLoc, m_lightPos.x, m_lightPos.y, m_lightPos.z);
glm::mat4 model;
glm::mat4 view;
glm::mat4 projection;
glm::mat3 normalMatrix;
normalMatrix = glm::mat3(glm::transpose(glm::inverse(model)));
view = m_camera->getViewMatrix();
projection = glm::perspective(glm::radians(m_camera->getFov()), (GLfloat)m_screenWidth / (GLfloat)m_screenHeight, 0.1f, 100.0f);
GLint normalMatrixLoc = glGetUniformLocation(m_cubeShader->getId(), "normalMatrix");
GLint modelLoc = glGetUniformLocation(m_cubeShader->getId(), "model");
GLint viewLoc = glGetUniformLocation(m_cubeShader->getId(), "view");
GLint projectionLoc = glGetUniformLocation(m_cubeShader->getId(), "projection");
glUniformMatrix3fv(normalMatrixLoc, 1, GL_FALSE, glm::value_ptr(normalMatrix));
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, glm::value_ptr(projection));
glBindVertexArray(m_cubeVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
// Draw light
m_lightShader->useShaderProgram();
model = glm::mat4();
model = glm::translate(model, m_lightPos);
model = glm::scale(model, glm::vec3(0.2f));
modelLoc = glGetUniformLocation(m_lightShader->getId(), "model");
viewLoc = glGetUniformLocation(m_lightShader->getId(), "view");
projectionLoc = glGetUniformLocation(m_lightShader->getId(), "projection");
glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, glm::value_ptr(projection));
glBindVertexArray(m_lightVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
I've tried to do the computations on view space but it doesn't work. I've tried to modify/normalize/use max() instead of clamp() but after a few hours on the problem. I'm out of any ideas.
You only have diffuse and specular light if the lightDir (direction from fragment to light) is in the direction of norm ( normal vector of fragment ). If they are directed against you can do without diffuse and specular light. In other words, if ther isn't any diffuse light (because diff is 0.0), there isn't any specular light too. Adapt your code like this:
void main()
{
// Vectors
vec3 norm = normalize(Normal);
vec3 lightDir = normalize(light.position - FragPos);
vec3 viewDir = normalize(viewPos - FragPos);
vec3 reflectDir = reflect(-lightDir, norm);
// Ambient
vec3 ambient = material.ambient * light.ambient;
vec3 result = ambient;
float dotNvLd = dot( norm, lightDir );
if ( dotNvLd > 0.0 ) // test if normal vector not directed against vector to light position
{
// Diffuse
float diff = min( dotNvLd, 1.0 );
vec3 diffuse = diff * material.diffuse * light.diffuse;
// Specular - The bug seems only here
float spec = pow(clamp(dot(viewDir, reflectDir), 0.0, 1.0), material.shininess);
vec3 specular = spec * material.specular * light.specular;
result = (diffuse + specular + ambient);
}
color = vec4(result, 1.0f);
// For test vectors
//color = vec4(specular, 1.0f);
}