Quatrième tutoriel OpenGL et exercices proposés

Bonjour,

Je poursuis le tutoriel http://www.opengl-tutorial.org/fr/be...-colored-cube/ qui est disponible également sur developpez.com

Je suis rendu au cube coloré. A la fin on propose des exercices, notamment afficher plusieurs objets.

Serait-il possible d'avoir de l'aide ? Il n'y a pas de solution donnée dans le tutoriel. Ou alors, je ne l'ai pas trouvée.

Voici ce que j'ai fait maintenant (en partant du tutoriel précédant) sans réussir à afficher 2 objets :

Code:

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// Include standard headers #include <stdio.h> #include <stdlib.h>   // Include GLEW #include <GL/glew.h>   // Include GLFW #include <GLFW/glfw3.h> GLFWwindow* window;   // Include GLM #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> using namespace glm;   #include <common/shader.hpp>   int main( void ) { // Initialise GLFW if( !glfwInit() ) { fprintf( stderr, "Failed to initialize GLFW\n" ); getchar(); return -1; }   glfwWindowHint(GLFW_SAMPLES, 4); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); //We don't want the old OpenGL   // Open a window and create its OpenGL context window = glfwCreateWindow( 1024, 768, "Tutorial 03 - Matrices test", NULL, NULL); if( window == NULL ){ fprintf( stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n" ); getchar(); glfwTerminate(); return -1; } glfwMakeContextCurrent(window);   // Initialize GLEW glewExperimental = true; // Needed for core profile if (glewInit() != GLEW_OK) { fprintf(stderr, "Failed to initialize GLEW\n"); getchar(); glfwTerminate(); return -1; }   // Ensure we can capture the escape key being pressed below glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);   // Dark blue background glClearColor(0.0f, 0.0f, 0.4f, 0.0f);   GLuint VertexArrayID; glGenVertexArrays(1, &VertexArrayID); glBindVertexArray(VertexArrayID);   // Create and compile our GLSL program from the shaders GLuint programID = LoadShaders( "SimpleTransform.vertexshader", "SingleColor.fragmentshader" );   // Get a handle for our "MVP" uniform GLuint MatrixID = glGetUniformLocation(programID, "MVP");   GLuint MatrixID2 = glGetUniformLocation(programID, "MVPTriangle");   // Projection matrix : 45� Field of View, 4:3 ratio, display range : 0.1 unit <-> 100 units glm::mat4 Projection = glm::perspective(glm::radians(45.0f), 4.0f / 3.0f, 0.1f, 100.0f); // Or, for an ortho camera : //glm::mat4 Projection = glm::ortho(-10.0f,10.0f,-10.0f,10.0f,0.0f,100.0f); // In world coordinates   // Camera matrix glm::mat4 View = glm::lookAt( glm::vec3(4,3,-3), // Camera is at (4,3,3), in World Space glm::vec3(0,0,0), // and looks at the origin glm::vec3(0,1,0) // Head is up (set to 0,-1,0 to look upside-down) ); // Model matrix : an identity matrix (model will be at the origin) glm::mat4 Model = glm::mat4(1.0f); // Our ModelViewProjection : multiplication of our 3 matrices glm::mat4 MVP = Projection * View * Model; // Remember, matrix multiplication is the other way around   glm::mat4 ModelTriangle = glm::mat4(1.0f); glm::mat4 MVPTriangle = Projection * View * ModelTriangle; // Remember, matrix multiplication is the other way around // static const GLfloat g_vertex_buffer_data[] = { // -1.0f, -1.0f, 0.0f, // 1.0f, -1.0f, 0.0f, // 0.0f, 1.0f, 0.0f, // };   // Our vertices. Three consecutive floats give a 3D vertex; Three consecutive vertices give a triangle. // A cube has 6 faces with 2 triangles each, so this makes 6*2=12 triangles, and 12*3 vertices static const GLfloat g_vertex_buffer_data[] = { -1.0f,-1.0f,-1.0f, // triangle 1 : begin -1.0f,-1.0f, 1.0f, -1.0f, 1.0f, 1.0f, // triangle 1 : end 1.0f, 1.0f,-1.0f, // triangle 2 : begin -1.0f,-1.0f,-1.0f, -1.0f, 1.0f,-1.0f, // triangle 2 : end 1.0f,-1.0f, 1.0f, -1.0f,-1.0f,-1.0f, 1.0f,-1.0f,-1.0f, 1.0f, 1.0f,-1.0f, 1.0f,-1.0f,-1.0f, -1.0f,-1.0f,-1.0f, -1.0f,-1.0f,-1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f,-1.0f, 1.0f,-1.0f, 1.0f, -1.0f,-1.0f, 1.0f, -1.0f,-1.0f,-1.0f, -1.0f, 1.0f, 1.0f, -1.0f,-1.0f, 1.0f, 1.0f,-1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,-1.0f,-1.0f, 1.0f, 1.0f,-1.0f, 1.0f,-1.0f,-1.0f, 1.0f, 1.0f, 1.0f, 1.0f,-1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,-1.0f, -1.0f, 1.0f,-1.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f,-1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 1.0f,-1.0f, 1.0f };   // One color for each vertex. They were generated randomly. static const GLfloat g_color_buffer_data[] = { 0.583f, 0.771f, 0.014f, 0.609f, 0.115f, 0.436f, 0.327f, 0.483f, 0.844f, 0.822f, 0.569f, 0.201f, 0.435f, 0.602f, 0.223f, 0.310f, 0.747f, 0.185f, 0.597f, 0.770f, 0.761f, 0.559f, 0.436f, 0.730f, 0.359f, 0.583f, 0.152f, 0.483f, 0.596f, 0.789f, 0.559f, 0.861f, 0.639f, 0.195f, 0.548f, 0.859f, 0.014f, 0.184f, 0.576f, 0.771f, 0.328f, 0.970f, 0.406f, 0.615f, 0.116f, 0.676f, 0.977f, 0.133f, 0.971f, 0.572f, 0.833f, 0.140f, 0.616f, 0.489f, 0.997f, 0.513f, 0.064f, 0.945f, 0.719f, 0.592f, 0.543f, 0.021f, 0.978f, 0.279f, 0.317f, 0.505f, 0.167f, 0.620f, 0.077f, 0.347f, 0.857f, 0.137f, 0.055f, 0.953f, 0.042f, 0.714f, 0.505f, 0.345f, 0.783f, 0.290f, 0.734f, 0.722f, 0.645f, 0.174f, 0.302f, 0.455f, 0.848f, 0.225f, 0.587f, 0.040f, 0.517f, 0.713f, 0.338f, 0.053f, 0.959f, 0.120f, 0.393f, 0.621f, 0.362f, 0.673f, 0.211f, 0.457f, 0.820f, 0.883f, 0.371f, 0.982f, 0.099f, 0.879f };   static const GLfloat g_vertex_buffer_data_triangle[] = { -1.0f, -1.0f, 0.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, };   GLuint vertexbuffer; glGenBuffers(1, &vertexbuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);   GLuint colorbuffer; glGenBuffers(1, &colorbuffer); glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(g_color_buffer_data), g_color_buffer_data, GL_STATIC_DRAW);   GLuint vertexbufferTriangle; glGenBuffers(1, &vertexbufferTriangle); glBindBuffer(GL_ARRAY_BUFFER, vertexbufferTriangle); glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data_triangle), g_vertex_buffer_data_triangle, GL_STATIC_DRAW);   // Enable depth test glEnable(GL_DEPTH_TEST); // Accept fragment if it closer to the camera than the former one glDepthFunc(GL_LESS); do{   // Clear the screen glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);   // Clear the screen //glClear( GL_COLOR_BUFFER_BIT );   // Use our shader glUseProgram(programID);   // Send our transformation to the currently bound shader, // in the "MVP" uniform glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]);   // 1rst attribute buffer : vertices glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glVertexAttribPointer( 0, // attribute. No particular reason for 0, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );       // 2nd attribute buffer : colors glEnableVertexAttribArray(1); glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glVertexAttribPointer( 1, // attribute. No particular reason for 1, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );       glDrawArrays(GL_TRIANGLES, 0, 12*3); // 3 indices starting at 0 -> 1 triangle     // Send our transformation to the currently bound shader, // in the "MVP" uniform glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVPTriangle[0][0]);   // 3rst attribute buffer : triangle glEnableVertexAttribArray(2); glBindBuffer(GL_ARRAY_BUFFER, vertexbufferTriangle); glVertexAttribPointer( 0, // attribute. No particular reason for 0, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );   // Draw the triangle ! glDrawArrays(GL_TRIANGLES, 0, 3); // 3 indices starting at 0 -> 1 triangle   glDisableVertexAttribArray(0);   // Swap buffers glfwSwapBuffers(window); glfwPollEvents();   } // Check if the ESC key was pressed or the window was closed while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS && glfwWindowShouldClose(window) == 0 );   // Cleanup VBO and shader glDeleteBuffers(1, &vertexbuffer); glDeleteProgram(programID); glDeleteVertexArrays(1, &VertexArrayID);   // Close OpenGL window and terminate GLFW glfwTerminate();   return 0; }

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Sinon, ce tutoriel est très bien. J'avance et je compte bien continuer.

Amicalement,

Stéphane

Si c'est pour afficher a nouveau le cube, tu translate la modelmatrix puis tu rappelle gldrawarray
Sinon pour un autre objet tu creer un nouveau vbo et tu appelle 2x gldrawarray en bindant chacun des vbos, mais du coup je te conseille de creer une classe pour cela

Qu'est ce qui s'affiche actuellement? Juste le cube? Juste le triangle? Aucun des deux?

La matrice Model de ton cube et de ton triangle sont toutes deux la matrice identité, donc même position et orientation de leur repère propre dans le repère monde. Tel que tu as définis les coordonnées de leurs vertices, il y a toutes les chances que le triangle se confonde à la surface du cube.

Bon ensuite la manière dont tu mets à jour les paramètres de ton vertex array object dans la boucle de rendu, c'est vraiment pas conseillé du tout (même si là je dirais que ça fonctionne).
Car là, tu es en train d'utiliser le même vertex array object, en modifiant le buffer associé au attribute index 0 (qui correspond à la position des vertices dans ton shader en toute logique) dans chaque boucle selon que tu fais le rendu du cube ou du triangle. Mais par contre tu réutilises toujours le même buffer de couleurs pour le attribute index 1. Enfin tu actives le attribute index 2 pour une raison obscure (ça ne sert à rien dans ton code).

Fais simple, surtout dans un cadre pédagogique: 1 vertex array object => 1 objet

Pour un petit programme simple dans ton cas, je ferais comme ceci:
Initialisation:
- Définition d'une model matrix pour le cube, et une pour le triangle, bien différentes l'une de l'autre (applique une translation à l'une pour faire simple).
- Compilation du program shader.
- Pour chaque objet:

• création des buffers (1 buffer de positions et 1 buffer de couleurs).
• creation d'un vertex array object
• binding des buffers avec le vertex array object + définition du format (glVertexAttribPointer) + activation des attribute index qui vont bien

Code:

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// Le Cube   // Creation du buffer contenant les positions des sommets du cube static const GLfloat cube_vertex_buffer_data[] = { ... }; GLuint cubeVertexBuffer; glGenBuffers(1, &cubeVertexBuffer); glBindBuffer(GL_ARRAY_BUFFER, cubeVertexBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(cube_vertex_buffer_data), cube_vertex_buffer_data, GL_STATIC_DRAW);   // Creation du buffer contenant les couleurs des sommets du cube static const GLfloat cube_color_buffer_data[] = { ... }; GLuint cubeColorBuffer; glGenBuffers(1, &cubeColorBuffer); glBindBuffer(GL_ARRAY_BUFFER, cubeColorBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(cube_color_buffer_data), cube_color_buffer_data, GL_STATIC_DRAW);   // Creation du Vertex array object GLuint cubeVertexArray; glGenVertexArrays(1, &cubeVertexArray); glBindVertexArray(cubeVertexArray);   // On configure le attribute index 0 du vertex array object glBindBuffer(GL_ARRAY_BUFFER, cubeVertexBuffer); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void *)0); // fonction multi taches qui associe : cubeVertexbuffer avec le binding index 0, attribute index 0 avec le binding index 0, et enfin définit comment le shader récupèrera les informations dans le buffer glEnableVertexAttribArray(0); // activation du attribute index 0   // On configure le attribute index 1 du vertex array object glBindBuffer(GL_ARRAY_BUFFER, cubeColorBuffer); glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void *)0); glEnableVertexAttribArray(1);   // Le Triangle // On repète la même chose avec d'autres array de positions/couleurs, d'autres buffers et un autre vertex array.

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- activation depth test

Boucle de rendu:
- glViewport si nécessaire
- glClear des color et depth buffer
- glUseProgram
- glBindVertexArray du cube
- glUniform des uniform specifiques au cube (mvp dans ton cas)
- glDrawArrays
- glBindVertexArray du triangle
- glUniform des uniform specifiques au triangle
- glDrawArrays
- swap

Bonsoir,

Je voudrais tout d'abord vous remercier de vos réponses, en particulier celle de Tony310.

J'ai réussi à afficher le triangle et le cube, grâce à toutes ces explications complémentaires.

Par contre, ce qui me pose problème, c'est la translation. Elle ne fonctionne pas.

Je vois que ça fonctionne car le triangle déborde, mais je n'arrive pas à en faire la translation. Je me demande si ce n'est pas quelque chose à modifier au niveau du shader ?

En tout cas merci. Grâce à vous,j'avance !

Stéphane

Code:

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// Include standard headers #include <stdio.h> #include <stdlib.h>   // Include GLEW #include <GL/glew.h>   // Include GLFW #include <GLFW/glfw3.h> GLFWwindow* window;   // Include GLM #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> using namespace glm;   #include <common/shader.hpp>   int main( void ) { // Initialise GLFW if( !glfwInit() ) { fprintf( stderr, "Failed to initialize GLFW\n" ); getchar(); return -1; }   glfwWindowHint(GLFW_SAMPLES, 4); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); //We don't want the old OpenGL   // Open a window and create its OpenGL context window = glfwCreateWindow( 1024, 768, "Tutorial 03 - Matrices test", NULL, NULL); if( window == NULL ){ fprintf( stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n" ); getchar(); glfwTerminate(); return -1; } glfwMakeContextCurrent(window);   // Initialize GLEW glewExperimental = true; // Needed for core profile if (glewInit() != GLEW_OK) { fprintf(stderr, "Failed to initialize GLEW\n"); getchar(); glfwTerminate(); return -1; }   // Ensure we can capture the escape key being pressed below glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);   // Dark blue background glClearColor(0.0f, 0.0f, 0.4f, 0.0f);   GLuint VertexArrayCube; glGenVertexArrays(1, &VertexArrayCube); glBindVertexArray(VertexArrayCube);   GLuint VertexArrayTriangle; glGenVertexArrays(1, &VertexArrayTriangle); glBindVertexArray(VertexArrayTriangle);   // Create and compile our GLSL program from the shaders GLuint programID = LoadShaders( "SimpleTransform.vertexshader", "SingleColor.fragmentshader" );   // Get a handle for our "MVP" uniform GLuint MatrixID = glGetUniformLocation(programID, "MVP");   GLuint MatrixID2 = glGetUniformLocation(programID, "MVPTriangle");   // Projection matrix : 45° Field of View, 4:3 ratio, display range : 0.1 unit <-> 100 units glm::mat4 Projection = glm::perspective(glm::radians(45.0f), 4.0f / 3.0f, 0.1f, 100.0f); // Or, for an ortho camera : //glm::mat4 Projection = glm::ortho(-10.0f,10.0f,-10.0f,10.0f,0.0f,100.0f); // In world coordinates   //Translation matrix     // Camera matrix glm::mat4 View = glm::lookAt( glm::vec3(4,3,-3), // Camera is at (4,3,3), in World Space glm::vec3(0,0,0), // and looks at the origin glm::vec3(0,1,0) // Head is up (set to 0,-1,0 to look upside-down) ); // Model matrix : an identity matrix (model will be at the origin) glm::mat4 Model = glm::mat4(1.0f); // Our ModelViewProjection : multiplication of our 3 matrices glm::mat4 MVP = Projection * View * Model; // Remember, matrix multiplication is the other way around   glm::mat4 Translation = glm::translate(Translation, glm::vec3(-50.0f,-5.0f,0.0f));   //glm::mat4 ModelTriangle = glm::mat4(1.0f); glm::mat4 MVPTriangle = Translation * MVP ; // Remember, matrix multiplication is the other way around // static const GLfloat g_vertex_buffer_data[] = { // -1.0f, -1.0f, 0.0f, // 1.0f, -1.0f, 0.0f, // 0.0f, 1.0f, 0.0f, // };   // Our vertices. Three consecutive floats give a 3D vertex; Three consecutive vertices give a triangle. // A cube has 6 faces with 2 triangles each, so this makes 6*2=12 triangles, and 12*3 vertices static const GLfloat g_vertex_buffer_data[] = { -1.0f,-1.0f,-1.0f, // triangle 1 : begin -1.0f,-1.0f, 1.0f, -1.0f, 1.0f, 1.0f, // triangle 1 : end 1.0f, 1.0f,-1.0f, // triangle 2 : begin -1.0f,-1.0f,-1.0f, -1.0f, 1.0f,-1.0f, // triangle 2 : end 1.0f,-1.0f, 1.0f, -1.0f,-1.0f,-1.0f, 1.0f,-1.0f,-1.0f, 1.0f, 1.0f,-1.0f, 1.0f,-1.0f,-1.0f, -1.0f,-1.0f,-1.0f, -1.0f,-1.0f,-1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f,-1.0f, 1.0f,-1.0f, 1.0f, -1.0f,-1.0f, 1.0f, -1.0f,-1.0f,-1.0f, -1.0f, 1.0f, 1.0f, -1.0f,-1.0f, 1.0f, 1.0f,-1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,-1.0f,-1.0f, 1.0f, 1.0f,-1.0f, 1.0f,-1.0f,-1.0f, 1.0f, 1.0f, 1.0f, 1.0f,-1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,-1.0f, -1.0f, 1.0f,-1.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f,-1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 1.0f,-1.0f, 1.0f };   // One color for each vertex. They were generated randomly. static const GLfloat g_color_buffer_data[] = { 0.583f, 0.771f, 0.014f, 0.609f, 0.115f, 0.436f, 0.327f, 0.483f, 0.844f, 0.822f, 0.569f, 0.201f, 0.435f, 0.602f, 0.223f, 0.310f, 0.747f, 0.185f, 0.597f, 0.770f, 0.761f, 0.559f, 0.436f, 0.730f, 0.359f, 0.583f, 0.152f, 0.483f, 0.596f, 0.789f, 0.559f, 0.861f, 0.639f, 0.195f, 0.548f, 0.859f, 0.014f, 0.184f, 0.576f, 0.771f, 0.328f, 0.970f, 0.406f, 0.615f, 0.116f, 0.676f, 0.977f, 0.133f, 0.971f, 0.572f, 0.833f, 0.140f, 0.616f, 0.489f, 0.997f, 0.513f, 0.064f, 0.945f, 0.719f, 0.592f, 0.543f, 0.021f, 0.978f, 0.279f, 0.317f, 0.505f, 0.167f, 0.620f, 0.077f, 0.347f, 0.857f, 0.137f, 0.055f, 0.953f, 0.042f, 0.714f, 0.505f, 0.345f, 0.783f, 0.290f, 0.734f, 0.722f, 0.645f, 0.174f, 0.302f, 0.455f, 0.848f, 0.225f, 0.587f, 0.040f, 0.517f, 0.713f, 0.338f, 0.053f, 0.959f, 0.120f, 0.393f, 0.621f, 0.362f, 0.673f, 0.211f, 0.457f, 0.820f, 0.883f, 0.371f, 0.982f, 0.099f, 0.879f };   static const GLfloat g_color_buffer_data_triangle[] = { 0.673f, 0.211f, 0.457f, 0.820f, 0.883f, 0.371f, 0.982f, 0.099f, 0.879f };   static const GLfloat g_vertex_buffer_data_triangle[] = { -5.0f, -5.0f, 0.0f, 2.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f };   GLuint vertexbuffer; glGenBuffers(1, &vertexbuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);   GLuint colorbuffer; glGenBuffers(1, &colorbuffer); glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(g_color_buffer_data), g_color_buffer_data, GL_STATIC_DRAW);   GLuint vertexbufferTriangle; glGenBuffers(1, &vertexbufferTriangle); glBindBuffer(GL_ARRAY_BUFFER, vertexbufferTriangle); glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data_triangle), g_vertex_buffer_data_triangle, GL_STATIC_DRAW);   GLuint colorbufferTriangle; glGenBuffers(1, &colorbufferTriangle); glBindBuffer(GL_ARRAY_BUFFER, colorbufferTriangle); glBufferData(GL_ARRAY_BUFFER, sizeof(g_color_buffer_data_triangle), g_color_buffer_data_triangle, GL_STATIC_DRAW);   // Enable depth test glEnable(GL_DEPTH_TEST); // Accept fragment if it closer to the camera than the former one glDepthFunc(GL_LESS); do{   // Clear the screen glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);   // Clear the screen //glClear( GL_COLOR_BUFFER_BIT );   // Use our shader glUseProgram(programID);   // Send our transformation to the currently bound shader, // in the "MVP" uniform glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]);   //Cube // 1rst attribute buffer : vertices glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glVertexAttribPointer( 0, // attribute. No particular reason for 0, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );       // 2nd attribute buffer : colors glEnableVertexAttribArray(1); glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glVertexAttribPointer( 1, // attribute. No particular reason for 1, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );       glDrawArrays(GL_TRIANGLES, 0, 12*3); // 3 indices starting at 0 -> 1 triangle   // glDisableVertexAttribArray(0); // glDisableVertexAttribArray(1);   // Send our transformation to the currently bound shader, // in the "MVP" uniform glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]);   // Triangle // 1rst attribute buffer : triangle glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexbufferTriangle); glVertexAttribPointer( 0, // attribute. No particular reason for 0, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );   // 2nd attribute buffer : colors glEnableVertexAttribArray(1); glBindBuffer(GL_ARRAY_BUFFER, colorbufferTriangle); glVertexAttribPointer( 1, // attribute. No particular reason for 1, but must match the layout in the shader. 3, // size GL_FLOAT, // type GL_FALSE, // normalized? 0, // stride (void*)0 // array buffer offset );   glUniformMatrix4fv(MatrixID2, 1, GL_FALSE, &MVPTriangle[0][0]); // Draw the triangle ! glDrawArrays(GL_TRIANGLES, 1, 3); // 3 indices starting at 0 -> 1 triangle   glDisableVertexAttribArray(0); glDisableVertexAttribArray(1);     // Swap buffers glfwSwapBuffers(window); glfwPollEvents();   } // Check if the ESC key was pressed or the window was closed while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS && glfwWindowShouldClose(window) == 0 );   // Cleanup VBO and shader glDeleteBuffers(1, &vertexbuffer); glDeleteBuffers(1, &colorbuffer); glDeleteBuffers(1, &vertexbufferTriangle); glDeleteBuffers(1, &colorbufferTriangle); glDeleteProgram(programID); glDeleteVertexArrays(1, &VertexArrayCube); glDeleteVertexArrays(2, &VertexArrayTriangle);   // Close OpenGL window and terminate GLFW glfwTerminate();   return 0; }

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Ordre des transformations :
1/ Model Matrix:

1. scale
2. rotation
3. translation

2/ View Matrix (la View Matrix est l'inverse de la model matrix de la camera)
3/ Projection Matrix

Ce qui donne :
model = translation * rotation * scale

Donc :
mvp = projection * view * model <=> mvp = projection * view * translation * rotation * scale

Tu calcules translation * projection * view, c'est pas bon. Tu dois revoir plus attentivement le tuto3 sur le site que tu utilises. Le shader quant à lui est très bien comme il est.

(Ça compilait vraiment ceci?

Code:

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glm::mat4 Translation = glm::translate(Translation, glm::vec3(-50.0f,-5.0f,0.0f));

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)

En résumé, fais quelque chose comme ça:

Code:

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1 2 3 4 5 6 7 8 9 10 11 12 13 14

glm::mat4 projection = ... glm::mat4 view = ... glm::mat4 viewProjection = projection * view;   // MVP Cube glm::mat4 modelCube = glm::mat4(1.0f); glm::mat4 mvpCube = viewProjection * modelCube; // on aurait pu écrire directement mvpCube = viewProjection, puisque modelCube est la matrice identité   // MVP Triangle glm::mat4 modelTriangle = glm::translate(glm::mat4(1.0f), glm::vec3(-50.0f,-5.0f,0.0f)); glm::mat4 mvpTriangle= viewProjection * modelTriangle;   // On peut aussi faire comme ceci: // glm::mat4 mvpTriangle = glm::translate(viewProjection, glm::vec3(-50.0f,-5.0f,0.0f)); // C'est equivalent à glm::mat4 mvpTriangle = viewProjection * glm::translate(glm::mat4(1.0f), glm::vec3(-50.0f,-5.0f,0.0f))

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Tony 310, je veux vous remercier pour toutes ces explications qui m'ont bien aidé.

Je mets en pause actuellement la programmation 3D à cause d'autres sujets d'étude prioritaires. Mais vraiment merci pour tout. Je pourrai y revenir efficacement plus tard.
J'ai déjà obtenu des résultats satisfaisants suite à votre aide !

Merci.

A bientôt !

Cordialement.

Stéphane