vbo

问题 i am new to openGL. Iam using apple documentation as my major referens http://developer.apple.com/library/ios/#documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/TechniquesforWorkingwithVertexData/TechniquesforWorkingwithVertexData.html#//apple_ref/doc/uid/TP40008793-CH107-SW6 My problem is that i am using openGL ES 1.1 and not 2 thus functions which are used in Listing 9-3 such as glVertexAttribPointer , glEnableVertexAttribArray are not recognized ... :) I trying to make the

问题 I came from this question: opengl vbo advice I use OpenGL 3.3 and will not to use deprecated features. Im using Assimp to import my blender models. But im a bit confused as to how much i should split them up in terms of VAO's and VBO's. First off a little side question. I use glDrawElements, do that mean i cannot interleave my vertex attributes or can the VAO figure out using the glVertexAttribPointer and the glDrawElements offset to see where my vertex position is? Main question i guess,

问题 I came from this question: opengl vbo advice I use OpenGL 3.3 and will not to use deprecated features. Im using Assimp to import my blender models. But im a bit confused as to how much i should split them up in terms of VAO's and VBO's. First off a little side question. I use glDrawElements, do that mean i cannot interleave my vertex attributes or can the VAO figure out using the glVertexAttribPointer and the glDrawElements offset to see where my vertex position is? Main question i guess,

问题 I'm working on OpenGL program and I must calculate a bounding box . I made the code to do it but I can't get vertexes coordinations from vertex buffer . Someone can explain me an easy way to get data from vertex buffer? I'm using Java for android and OpenGL es 回答1: If you use OpenGL ES 3.0 or later, you can use glMapBufferRange() to access buffer data directly. See the man page for details about the functionality, and the GLES30 documentation for details about the Java bindings in Android. I

问题 My code is working as it should but it might be a coincidence and I don't want to dwell on a bug later so I'm trying to keep it as clean as possible: I do the following for initializing a mesh: Gen and bind VBO and buffer data Gen and bind IBO and buffer data Gen and bind VAO Bind same VBO as before, generated in 1. Enable Vertex Attribute Arrays that I need and set the Vertex Attribute Pointers Bind the IBO again (don't exactly know why) BindVertexArray back to 0 so that I don't mess up the

问题 I'm trying to load an object and use VBO and glDrawArrays() to render it. The problem is that a simple float pointer like float f[]={...} does not work in my case, because I passed the limit of values that this pointer can store. So my solution was to use a vector. And it's not working... Here is my code: unsigned int vbo; vector<float*> vert; ... vert.push_back(new float(i*size)); vert.push_back(new float(height*h)); vert.push_back(new float(j*size)); ... glGenBuffers(1, &vbo); glBindBuffer

问题 I have to draw a buffer that holds a couple thousand vertices. I am using a vbo to store the data. I know I will have to update the VBO many times - but only in small parts at a time. So I am wondering what the best method to doing so is: Split VBO up into smaller VBOs (that hold like 300 verts) and then update individual VBOs with 1 call? One big VBO and use lots of glBufferSubData() calls? Use glMapBuffer() and one big VBO? 回答1: There is another option, which is a bit like option 3 - use

问题 What I want to do is to render a mesh multiple times with the same vbo but with different offset. Example: //Load VBO glGenBuffers(2, &bufferObjects[0]); glBindBuffer(GL_ARRAY_BUFFER, bufferObjects[VERTEX_DATA]); glBufferData(GL_ARRAY_BUFFER, sizeof(float)*size(vertices)*3, &vertices[0], GL_STATIC_DRAW); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bufferObjects[INDEX_DATA]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int)*size(indices), &indices[0], GL_STATIC_DRAW); //Render VBO glBindBuffer(GL

问题 #define GLEW_STATIC #include <GL\glew.h> #include <GLFW\glfw3.h> #include <GL\glew.h> #include <glm.hpp> #include <iostream> #include <fstream> #include <string> #define WIDTH 800 #define HEIGHT 600 #define TITLE "Dynamic" GLFWwindow* window; int vaoID; float vertices[] = {-0.5f, 0.5f, 0, -0.5f, -0.5f, 0, 0.5f, 0.5f, 0, 0.5f, 0.5f, 0, -0.5f, -0.5f, 0, 0.5f, -0.5f, 0}; void loadToVAO(float vertices[]); void update() { loadToVAO(vertices); while (!glfwWindowShouldClose(window)) { glfwPollEvents

问题 After searching and reading about Modern OpenGL in order to upgrade my existing project, I'm a bit confused, since my 3D framework based on OpenGL 2.1. so, as far as I learn... We need to generate our Vertex-Buffer-Objects from vertices, indices, normals, colors, uvs, etc. then we can use GLM for matrix transformation, and we only use VBO to create or manipulate meshes, finally we pass everything into GLSL vertex shader like this... glm::mat4 MVP = projection * view * model;