vbo

问题 I have just started learning about vertex buffer objects in C++. I am reading a book about OpenGL that says that VBO rendering is more efficient than other forms of rendering because the data is stored on the GPU instead of on the heap. However, I am confused how this could be if you still have to load an array of data from the heap to the GPU. Every few seconds, I update the vertex data of my program, which means that I must then use glBufferData() to refresh the data to update to the new

问题 I'm trying to write a game that deals with many circles (well, Triangle Fans, but you get the idea). Each circle will have an x position, a y position, and a mass property. Every circle's mass property will be different. Also, I want to color some groups of circles different, while keeping a transparent circle center, and fading to opaque along the perimeter of the circles. I was told to use VBOs, and have been Googling all day. I would like a full example on how I would draw these circles

问题 I'm trying to display a texture with height-field (think kinect here). What I got gives an 0x501 error, no idea why. So the questions are: why am I getting this 0x501 error? And the rest of the code: should this work? // void EC(void) is an inline function that checks for OpenGL errors and shows them // url_width / url_height: dimensions of the frame and by that the dimensions of the texture/height field // texture_id: id for the coordinates of each point in the texture // vector_id: id for

问题 I´m trying to make a dynamic point cloud visualizer. The points are updated every frame with Kinect Sensor. To grab the frames I´m using OpenCV and GLUT to display. The OpenCV API returns a 640 x 480 (float *), for the points xyz position , and a 640 x 480 (int *) for the rgb color data. To get the maximum performance, I´m trying to use Vertex Buffer Object in stream mode instead of a simple Vertex Array. I´m being able to render it with Vertex Array, but nothing is being rendered with my VBO

问题 Is there any way to use differently sized buffers for glDrawElements? I somehow want to map vertices to texture coordinates, so that the texture coordinate buffer is able to be actually smaller than the vertex buffer. Example: vertex buffer has 16 vertices and the texture coordinate buffer has 6 vertices. vertex_buffer[0] -> texture_coordinates_buffer[0] vertex_buffer[1] -> texture_coordinates_buffer[1] vertex_buffer[2] -> texture_coordinates_buffer[2] vertex_buffer[3] -> texture_coordinates

问题 I'm trying to get a super simple GLFW and VBO example running, but I'm stuck. I've used glBegin and glEnd for other projects, but I'm trying to update my code to work with OpenGL ES 2, but for now I just want to be as forward compatible as possible. From some examples online, I've come up with the following code: #include <stdlib.h> #include <GL/glfw3.h> #include <stdio.h> #define bool int #define true 1 #define false 0 const int width = 800; const int height = 600; bool opened = true; GLuint

问题 I started to follow a tutorial about modern OpenGL rendering and altered the c++ code from a VBO lesson to work with LWJGL. I initialized the VBO with the following code: int vbo = GL15.glGenBuffers(); GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo); GL15.glBufferData(GL15.GL_ARRAY_BUFFER, buffer, GL15.GL_STATIC_DRAW); "buffer" is initialized as FloatBuffer buffer = BufferUtils.createFloatBuffer(9); and then filled with {-0.5f, -0.5f, 0, 0.5f, -0.5f, 0, 0, 0.5f, 0} via buffer.put(val) My game

问题 I'm stuck with my program rendering all the particles, but only updating 1 particle on 3. Here's what I've done to test it. I made a vbo with 10 of my particles, put them all aligned veticaly and set the compute shader to modify their x position every update (pos.x+=0.1). Here's the result after about 1-2 seconds (image is 1:5 scale) : I use local_size_x = 1, local_size_y = 1 and local_size_z = 1, then DispatchCompute(10,1,1) . Am I doing something wrong with the invocation ids? Update

问题 I've got a training app written in winapi So, I've got GL initialized there and I've got node-based system, that can be described by couple of classes class mesh { GLuint vbo_index; //this is for having unique vbo float *vertex_array; float *normal_array; unsigned int vertex_count; etc.. //all those mesh things. .... } class node { bool is_mesh; //the node may or may not represent a mesh mesh * mesh_ptr; //if it does then this pointer is a valid address } I've also got 2 global variables for

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 8 years ago . I've setup a Vertex Buffer Object (VBO) with vertex and index data. I've also created a GLprogram to use custom shaders, so I call glUseProgram within my code. My vertex data changes every frame, so I've supplied