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Enalis

OpenGL GLSL

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I have been working on getting all the shaders I want to use with a working example. I recently added per pixel lighting and shadow mapping with PCF. I wanted to add parallax mapping. So I looked around for an example and found one at www.ultimategameprogramming.com under opengl page 10. I decided to use my shader class and adapt the code to work with mine. So that's what I did. I'll post my code for everyone to see, but as for results, right now I only get a very dark quad textured with the detail map but it's extremely dark. And it seems that none of the parallax effects are working. Here is some code...
// these are the parts of my init function that pertains to the shader
LoadGLTexture(&parallaxTestTextures[DECAL_TEXTURE], "data/decal.PNG", LINEAR_FILTERING, &screenSettings.anisotropy);
LoadGLTexture(&parallaxTestTextures[NORMAL_TEXTURE], "data/normal.PNG", LINEAR_FILTERING, &screenSettings.anisotropy);
LoadGLTexture(&parallaxTestTextures[HEIGHT_TEXTURE], "data/height.PNG", LINEAR_FILTERING, &screenSettings.anisotropy);

parallaxShader.InitShaders("shaders/parallaxVS.glsl", "shaders/parallaxPS.glsl");

// NOTE: All shaders turned off in the beginning of render func and turned on in the function they are used in and turned off at the end.

// this draws the object and is called once in my render function
void DrawParallaxMappedObject(void){
	glPushMatrix();
	glDisable(GL_BLEND);
	glTranslatef(0.0f, 0.0f, -7.5f);
	glRotatef(-yRot, 1.0f, 0.0f, 0.0f);
	glRotatef(-xRot, 0.0f, 1.0f, 0.0f);

	// Here we pass in the light position
	parallaxShader.SetFloat4(parallaxShader.GetVariable("lightPos"), g_LightPosition[0], g_LightPosition[1], g_LightPosition[2], g_LightPosition[3]);
	parallaxShader.SetFloat3(parallaxShader.GetVariable("camPos"), camera.xPos, camera.yPos, camera.zPos);
	// Here pass in our texture unit 0 (GL_TEXTURE0_ARB) for "texture1" in the shader.
	parallaxShader.SetInt(parallaxShader.GetVariable("decal"), 0);
	parallaxShader.SetInt(parallaxShader.GetVariable("parallaxMap"), 1);
	parallaxShader.SetInt(parallaxShader.GetVariable("normalMap"), 2);

	// we need to turn on our shader for the parallax objects
	parallaxShader.TurnOn();

	glEnable(GL_LIGHTING);	
	float lightValue[4] = {1.0f, 1.0f, 1.0f, 1.0f};
	glLightfv(GL_LIGHT0, GL_AMBIENT, lightValue);
//	glDisable(GL_LIGHTING);
	
	// now we'll draw our objects
	// Bind both images to unit 0 and 1 respectively.
	glActiveTextureARB(GL_TEXTURE0_ARB);
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, parallaxTestTextures[DECAL_TEXTURE]);

	glActiveTextureARB(GL_TEXTURE1_ARB);
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, parallaxTestTextures[HEIGHT_TEXTURE]);

	glActiveTextureARB(GL_TEXTURE2_ARB);
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, parallaxTestTextures[NORMAL_TEXTURE]);

	// Draw our wall.  Keep in mind we are sending the s tangent through glColor3f().
	glBegin(GL_TRIANGLES);

//		glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0f, 1.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0f, 1.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE2_ARB, 0.0f, 1.0f);
		glTexCoord2f(0.0f, 1.0f);    glNormal3f(0.0f, 0.0f, 1.0f);
		glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(-10.0f, 10.0f, 0.0f);

//		glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0f, 0.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0f, 0.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE2_ARB, 0.0f, 0.0f);
		glTexCoord2f(0.0f, 0.0f);    glNormal3f(0.0f, 0.0f, 1.0f);
		glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(-10.0f, -10.0f, 0.0f);

//		glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 1.0f, 0.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0f, 0.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE2_ARB, 1.0f, 0.0f);
		glTexCoord2f(1.0f, 0.0f);    glNormal3f(0.0f, 0.0f, 1.0f);
		glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(10.0f, -10.0f, 0.0f);

		// Triangle 2.
//		glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 1.0f, 0.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0f, 0.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE2_ARB, 1.0f, 0.0f);
		glTexCoord2f(1.0f, 0.0f);    glNormal3f(0.0f, 0.0f, 1.0f);
		glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(10.0f, -10.0f, 0.0f);

//		glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 0.0f, 1.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0f, 1.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE2_ARB, 0.0f, 1.0f);
		glTexCoord2f(0.0f, 1.0f);    glNormal3f(0.0f, 0.0f, 1.0f);
		glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(-10.0f, 10.0f, 0.0f);

//		glMultiTexCoord2fARB(GL_TEXTURE0_ARB, 1.0f, 1.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0f, 1.0f);
//		glMultiTexCoord2fARB(GL_TEXTURE2_ARB, 1.0f, 1.0f);
		glTexCoord2f(1.0f, 1.0f);    glNormal3f(0.0f, 0.0f, 1.0f);
		glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(10.0f, 10.0f, 0.0f);

	glEnd();

	glActiveTextureARB(GL_TEXTURE1_ARB);
	glBindTexture(GL_TEXTURE_2D, NULL);
	glDisable(GL_TEXTURE_2D);
	
	glActiveTextureARB(GL_TEXTURE2_ARB);
	glBindTexture(GL_TEXTURE_2D, NULL);
	glDisable(GL_TEXTURE_2D);

	glActiveTextureARB(GL_TEXTURE0_ARB);
	glBindTexture(GL_TEXTURE_2D, NULL);
//	glDisable(GL_TEXTURE_2D);

	glDisable(GL_LIGHTING);

	// were done rendering parallax shaded objects so turn it off
	parallaxShader.TurnOff();
	glPopMatrix();
}

// here are the shaders vertex shader first
/*
 www.UltimateGameProgramming.com
 Parallax Mapping Vertex Shader in GLSlang.
 Created by the Programming Ace.


 Input...
   gl_Vertex = vertex object space position.
   gl_Normal = vertex normal.
   gl_ModelViewProjectionMatrix = current model view projection matrix.
   gl_ModelViewMatrixInverse = current inverse model view matrix.
   gl_MultiTexCoord0.xy = texture coords for unit 0.


 Varying...
   texCoord = output vertex texture coordinates.
   direction = light direction.
   viewDir = camera - vertex direction.


 Output...
   gl_Position = output vertex position.
*/


varying vec2 texCoord;
varying vec3 direction;
varying vec3 viewDir;

uniform vec4 lightPos;
uniform vec3 camPos;


void main()
{
   // Transform vertex to clip space and save tex coord.
   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
   texCoord = gl_MultiTexCoord0.xy;
   
   // Calculate world space position.
   vec4 pos = gl_ModelViewMatrixInverse * gl_Vertex;
   
   // Calculate the light direction.
   direction = lightPos - gl_Vertex;
   
   // Get the normal.
   vec3 normal = gl_NormalMatrix * gl_Normal;
   
   // Save a copy of the s tangent which was sent through the color (glColor3f).
   vec3 sTangent = gl_Color.xyz;

   // Calculate the binormal as the cross between tangent and normal.
   vec3 binormal = cross(sTangent, normal);
   
   // Create the matrix used to convert the light direction to texture space.
   mat3 tbnMatrix = mat3(sTangent, binormal, normal);

   // Convert light direction to texture space.
   direction = tbnMatrix * direction;

   // Calculate the view direction then convert it to texture space.
   viewDir = camPos - pos;
   viewDir = tbnMatrix * viewDir;
}

// and now the fragment shader
/*
 www.UltimateGameProgramming.com
 Parallax Mapping Pixel Shader in GLSlang.
 Created by the Programming Ace.


 Varying...
   texCoord = output vertex texture coordinates for unit 0.
   direction = light direction in texture space.
   viewDir = camera - vertex direction.


 Uniform...
   decal = decal image texture.
   parallaxMap = height map texture.
   normalMap = bump map texture.

 Output...
   gl_FragColor = output vertex color.
*/


varying vec2 texCoord;
varying vec3 direction;
varying vec3 viewDir;

uniform sampler2D decal;
uniform sampler2D parallaxMap;
uniform sampler2D normalMap;


void main()
{
//   float scale = 0.04f;
//   float bias = 0.02f;
   
   float scale = 0.5f;
   float bias = 0.25f;
   // Normalize the light direction and view vector on a per pixel level.
   direction = normalize(direction);
   viewDir = normalize(viewDir);
   
   // Get the height value and calculate the new texture coord.
   vec3 heightTex = texture2D(parallaxMap, texCoord).xyz;
   float height = scale * heightTex - bias;
   vec2 newTexCoord = height * viewDir + texCoord;
   
   // Get the bump map normal.
   vec3 normalTex = texture2D(normalMap, newTexCoord).xyz;
   
   // Convert from 0 to 1 range to -1 to 1.
   normalTex = (normalTex - 0.5f) * 2;

   // Calculate the bump value as n dot l.
   float dp = saturate(dot(normalTex, direction));
   
   // Get the decal texture color with the new tex coords.
   vec4 decalCol = texture2D(decal, newTexCoord);
   
   // material properties.
   vec4 abmient = vec4(1.0f, 1.0f, 1.0f, 1.0f);
   //vec4 abmient = vec4(0.4f, 0.4f, 0.4f, 1.0f);
   vec4 diffuse = vec4(0.8f, 0.8f, 0.8f, 1.0f);
   diffuse = diffuse * dp;
   
   // Combine the decal with the bump value.
   gl_FragColor = (abmient + diffuse) * decalCol;
}


If you need any more info such as a screenshot please respond with such requests

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1. Post a screenshot
2. Why are you computing world space vertex position using inverse of the modelview matrix? You should be using normal modelview.

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Looks like there are many problems.


That's not world space (eye space, camera space). This is
vec4 pos = gl_ModelViewMatrix * gl_Vertex;


This is wrong. Just use gl_Normal
// Get the normal.
vec3 normal = gl_NormalMatrix * gl_Normal;

This is not ideal. Send as a texcoord
vec3 sTangent = gl_Color.xyz;

I'm not 100% sure about this
// Convert light direction to texture space.
direction = tbnMatrix * direction;

You can try this to be sure
direction2.x = dot(sTangent, direction);
direction2.y = dot(binormal, direction);
direction2.z = dot(gl_Normal, direction);

You can put the height map into the alpha of the normal map.

normalTex = (normalTex - 0.5f) * 2;
Maybe
normalTex = 2.0 * normalTex + 1.0;
is faster

Secondly, notice the "f" in 0.5f. Remove that.
normalTex = (normalTex - 0.5f) * 2;

It's also a good idea to make that into
normalTex = normalize(2.0 * normalTex + 1.0);

abmient? You mean ambient

This is from UltimateGameProgramming? I'll be sure not to go there.
Why don't you download Terry Welsh's pdf on the subject. He explains it well and code is better.

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I made all of those changes but it didn't seem to work, well I made all but the direction one, Did you mean to have it define another direction and add those lines after the original or did you mean for those to replace direction. Also, I was wondering if the shader recompiles every time it's run. And if not is there a way to force it to because I'm not sure my changes are being made. I've severely altered one of my other shaders but it didn't seem to do anything?

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You replace the code about the direction. I just made up a variable called direction2. You can name it as directionInTangentSpace if it's clearer, but the important thing is not to do this

direction.x = dot(sTangent, direction);
direction.y = dot(binormal, direction);
direction.z = dot(gl_Normal, direction);

Because the first line already modifies direction.x!

Moer comments
If you are using shaders, glEnable and glDisable are ignored. Shaders are a magical world where these have no effect because your shader is executed as written.

glDisable(GL_LIGHTING); Useless!
glEnable(GL_TEXTURE_2D); Useless!
glEnable(GL_LIGHTING); Useless!

Why bind 0?
glBindTexture(GL_TEXTURE_2D, NULL); Useless!

I know that this is for learning, but to be honest, UltimateGameProgramming has done a awful job.

Quote:
Also, I was wondering if the shader recompiles every time it's run. And if not is there a way to force it to because I'm not sure my changes are being made. I've severely altered one of my other shaders but it didn't seem to do anything?


It probably compiles when you call
parallaxShader.InitShaders("shaders/parallaxVS.glsl", "shaders/parallaxPS.glsl");
It's also a good idea to check if compilation fails because your GLSL code was wrong. DON'T put a f after floats! Some old nVidia drivers accepted it but doesn't work elsewhere.

This is Terry Welshs pdf
He also had a working demo but who knows where it is now.
http://www.cs.ualberta.ca/~keith/610/papers/parallax_mapping.pdf

Try these guys for learning to use shaders (GLSL)
http://lighthouse3d.com/opengl/

GLSL specification
http://www.opengl.org/documentation/glsl/

Tools for GLSL, runnable programs, GLSL validator to check your shaders for errors (reference GLSL compiler).
http://developer.3dlabs.com/

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      #shader vertex #version 330 core layout(location = 0) in vec4 aPos; layout(location = 1) in vec2 aTexCoord; out vec2 t_TexCoord; uniform mat4 u_MVP; void main() { gl_Position = u_MVP * aPos; t_TexCoord = aTexCoord; } #shader fragment #version 330 core out vec4 aColor; in vec2 t_TexCoord; uniform sampler2D u_Texture; void main() { aColor = texture(u_Texture, t_TexCoord); } Also i'm pretty sure that every time i'm hitting the up, down, left and right arrows on the keyboard, i'm changing the model Matrix of the Player and not the others.
       
      Window Class:
      #include "Window.h" #include <GL/glew.h> #include <GLFW/glfw3.h> #include "Error.h" #include "Renderer.h" #include "Scene.h" #include "Input.h" //Global Variables. int screen_width, screen_height; //On Window Resize. void OnWindowResize(GLFWwindow *window, int width, int height); //Implementation Structure. struct Window::Implementation { //GLFW Window. GLFWwindow *GLFW_window; //Renderer. Renderer *renderer; //Delta Time. double delta_time; //Frames Per Second. int fps; //Scene. Scene *scnene; //Input. Input *input; //Deconstructor. ~Implementation(); }; //Window Constructor. Window::Window(std::string title, int width, int height) { //Initializing width and height. screen_width = width; screen_height = height; //Create Pointer To Implementation. m_Impl = new Implementation(); //Try initializing GLFW. if (!glfwInit()) { std::cout << "GLFW could not be initialized!" << std::endl; std::cout << "Press ENTER to exit..." << std::endl; std::cin.get(); exit(-1); } //Setting up OpenGL Version 3.3 Core Profile. glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); /* Create a windowed mode window and its OpenGL context */ m_Impl->GLFW_window = glfwCreateWindow(width, height, title.c_str(), NULL, NULL); if (!m_Impl->GLFW_window) { std::cout << "GLFW could not create a window!" << std::endl; std::cout << "Press ENTER to exit..." << std::endl; std::cin.get(); glfwTerminate(); exit(-1); } /* Make the window's context current */ glfwMakeContextCurrent(m_Impl->GLFW_window); //Initialize GLEW. if(glewInit() != GLEW_OK) { std::cout << "GLEW could not be initialized!" << std::endl; std::cout << "Press ENTER to exit..." << std::endl; std::cin.get(); glfwTerminate(); exit(-1); } //Enabling Blending. GLCall(glEnable(GL_BLEND)); GLCall(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)); //Setting the ViewPort. GLCall(glViewport(0, 0, width, height)); //**********Initializing Implementation**********// m_Impl->renderer = new Renderer(); m_Impl->delta_time = 0.0; m_Impl->fps = 0; m_Impl->input = new Input(this); //**********Initializing Implementation**********// //Set Frame Buffer Size Callback. glfwSetFramebufferSizeCallback(m_Impl->GLFW_window, OnWindowResize); } //Window Deconstructor. Window::~Window() { delete m_Impl; } //Window Main Loop. void Window::MainLoop() { //Time Variables. double start_time = 0, end_time = 0, old_time = 0, total_time = 0; //Frames Counter. int frames = 0; /* Loop until the user closes the window */ while (!glfwWindowShouldClose(m_Impl->GLFW_window)) { old_time = start_time; //Total time of previous frame. start_time = glfwGetTime(); //Current frame start time. //Calculate the Delta Time. m_Impl->delta_time = start_time - old_time; //Get Frames Per Second. if (total_time >= 1) { m_Impl->fps = frames; total_time = 0; frames = 0; } //Clearing The Screen. m_Impl->renderer->Clear(0, 0, 0); //Render The Scene. if (m_Impl->scnene != NULL) m_Impl->scnene->Render(this); //Updating the Screen. m_Impl->renderer->Update(m_Impl->GLFW_window); //Increasing frames counter. frames++; //End Time. end_time = glfwGetTime(); //Total time after the frame completed. total_time += end_time - start_time; } //Terminate GLFW. glfwTerminate(); } //Load Scene. void Window::LoadScene(Scene * scene) { //Set the scene. m_Impl->scnene = scene; } //Get Delta Time. double Window::GetDeltaTime() { return m_Impl->delta_time; } //Get FPS. int Window::GetFPS() { return m_Impl->fps; } //Get Width. int Window::GetWidth() { return screen_width; } //Get Height. int Window::GetHeight() { return screen_height; } //Get Input. Input * Window::GetInput() { return m_Impl->input; } Renderer * Window::GetRenderer() { return m_Impl->renderer; } GLFWwindow * Window::GetGLFWindow() { return m_Impl->GLFW_window; } //Implementation Deconstructor. Window::Implementation::~Implementation() { delete renderer; delete input; } //OnWindowResize void OnWindowResize(GLFWwindow *window, int width, int height) { screen_width = width; screen_height = height; //Updating the ViewPort. GLCall(glViewport(0, 0, width, height)); }  
      Brain Class
      #include "Brain.h" #include "Sprite.h" #include "Window.h" struct Brain::Implementation { //Just A Flag. bool started; //Window Pointer. Window *window; //Sprite Pointer. Sprite *sprite; }; Brain::Brain(Window *window, Sprite *sprite) { //Create Pointer To Implementation. m_Impl = new Implementation(); //Initialize Implementation. m_Impl->started = true; m_Impl->window = window; m_Impl->sprite = sprite; } Brain::~Brain() { //Delete Pointer To Implementation. delete m_Impl; } void Brain::Start() { } void Brain::Update() { } Window * Brain::GetWindow() { return m_Impl->window; } Sprite * Brain::GetSprite() { return m_Impl->sprite; } bool Brain::GetStart() { return m_Impl->started; } void Brain::SetStart(bool value) { m_Impl->started = value; } Script Class (Its a Brain Subclass!!!)
      #include "Script.h" Script::Script(Window *window, Sprite *sprite) : Brain(window, sprite) { } Script::~Script() { } void Script::Start() { std::cout << "Game Started!" << std::endl; } void Script::Update() { Input *input = this->GetWindow()->GetInput(); Sprite *sp = this->GetSprite(); //Move this sprite. this->GetSprite()->Move(200 * this->GetWindow()->GetDeltaTime(), input->GetKeyDown("left"), input->GetKeyDown("right"), input->GetKeyDown("up"), input->GetKeyDown("down")); std::cout << sp->GetTag().c_str() << ".x = " << sp->GetPos()->x << ", " << sp->GetTag().c_str() << ".y = " << sp->GetPos()->y << std::endl; }  
      Main:
      #include "SpaceShooterEngine.h" #include "Script.h" int main() { Window w("title", 600,600); Scene *scene = new Scene(); Sprite *player = new Sprite("Resources/Images/player.png", "Player", 100,100); Sprite *other = new Sprite("Resources/Images/cherno.png", "Other", 400, 100); Sprite *other2 = new Sprite("Resources/Images/cherno.png", "Other", 300, 400); Brain *brain = new Script(&w, player); player->AddBrain(brain); scene->AddSprite(player); scene->AddSprite(other); scene->AddSprite(other2); w.LoadScene(scene); w.MainLoop(); return 0; }  
       
      I literally can't find what is wrong. If you need more code, ask me to post it. I will also attach all the source files.
      Brain.cpp
      Error.cpp
      IndexBuffer.cpp
      Input.cpp
      Renderer.cpp
      Scene.cpp
      Shader.cpp
      Sprite.cpp
      Texture.cpp
      VertexArray.cpp
      VertexBuffer.cpp
      VertexBufferLayout.cpp
      Window.cpp
      Brain.h
      Error.h
      IndexBuffer.h
      Input.h
      Renderer.h
      Scene.h
      Shader.h
      SpaceShooterEngine.h
      Sprite.h
      Texture.h
      VertexArray.h
      VertexBuffer.h
      VertexBufferLayout.h
      Window.h
    • By Cristian Decu
      Hello fellow programmers,
      For a couple of days now i've decided to build my own planet renderer just to see how floating point precision issues
      can be tackled. As you probably imagine, i've quickly faced FPP issues when trying to render absurdly large planets.
       
      I have used the classical quadtree LOD approach;
      I've generated my grids with 33 vertices, (x: -1 to 1, y: -1 to 1, z = 0).
      Each grid is managed by a TerrainNode class that, depending on the side it represents (top, bottom, left right, front, back),
      creates a special rotation-translation matrix that moves and rotates the grid away from the origin so that when i finally
      normalize all the vertices on my vertex shader i can get a perfect sphere.
      T = glm::translate(glm::dmat4(1.0), glm::dvec3(0.0, 0.0, 1.0)); R = glm::rotate(glm::dmat4(1.0), glm::radians(180.0), glm::dvec3(1.0, 0.0, 0.0)); sides[0] = new TerrainNode(1.0, radius, T * R, glm::dvec2(0.0, 0.0), new TerrainTile(1.0, SIDE_FRONT)); T = glm::translate(glm::dmat4(1.0), glm::dvec3(0.0, 0.0, -1.0)); R = glm::rotate(glm::dmat4(1.0), glm::radians(0.0), glm::dvec3(1.0, 0.0, 0.0)); sides[1] = new TerrainNode(1.0, radius, R * T, glm::dvec2(0.0, 0.0), new TerrainTile(1.0, SIDE_BACK)); // So on and so forth for the rest of the sides As you can see, for the front side grid, i rotate it 180 degrees to make it face the camera and push it towards the eye;
      the back side is handled almost the same way only that i don't need to rotate it but simply push it away from the eye.
      The same technique is applied for the rest of the faces (obviously, with the proper rotations / translations).
      The matrix that result from the multiplication of R and T (in that particular order) is send to my vertex shader as `r_Grid'.
      // spherify vec3 V = normalize((r_Grid * vec4(r_Vertex, 1.0)).xyz); gl_Position = r_ModelViewProjection * vec4(V, 1.0); The `r_ModelViewProjection' matrix is generated on the CPU in this manner.
      // No the most efficient way, but it works. glm::dmat4 Camera::getMatrix() { // Create the view matrix // Roll, Yaw and Pitch are all quaternions. glm::dmat4 View = glm::toMat4(Roll) * glm::toMat4(Pitch) * glm::toMat4(Yaw); // The model matrix is generated by translating in the oposite direction of the camera. glm::dmat4 Model = glm::translate(glm::dmat4(1.0), -Position); // Projection = glm::perspective(fovY, aspect, zNear, zFar); // zNear = 0.1, zFar = 1.0995116e12 return Projection * View * Model; } I managed to get rid of z-fighting by using a technique called Logarithmic Depth Buffer described in this article; it works amazingly well, no z-fighting at all, at least not visible.
      Each frame i'm rendering each node by sending the generated matrices this way.
      // set the r_ModelViewProjection uniform // Sneak in the mRadiusMatrix which is a matrix that contains the radius of my planet. Shader::setUniform(0, Camera::getInstance()->getMatrix() * mRadiusMatrix); // set the r_Grid matrix uniform i created earlier. Shader::setUniform(1, r_Grid); grid->render(); My planet's radius is around 6400000.0 units, absurdly large, but that's what i really want to achieve;
      Everything works well, the node's split and merge as you'd expect, however whenever i get close to the surface
      of the planet the rounding errors start to kick in giving me that lovely stairs effect.
      I've read that if i could render each grid relative to the camera i could get better precision on the surface, effectively
      getting rid of those rounding errors.
       
      My question is how can i achieve this relative to camera rendering in my scenario here?
      I know that i have to do most of the work on the CPU with double, and that's exactly what i'm doing.
      I only use double on the CPU side where i also do most of the matrix multiplications.
      As you can see from my vertex shader i only do the usual r_ModelViewProjection * (some vertex coords).
       
      Thank you for your suggestions!
       
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