vbo

问题 Is there a max size for vertex buffer objects binded to GL_ARRAY_BUFFER or GL_ELEMENT_ARRAY_BUFFER??? Originally, I was drawing a mesh composed of 16 submeshes. For each submesh, I created a vertex buffer and during the rendering phase, I called glDrawElements. This worked fine on the iOS simulator, but when I tried to render to my device, the screen flashes constantly and the meshes aren't displayed. I then did some reading and found that you shouldn't call glDrawElements too many times

问题 Is it possible to store different vertex attributes in different vertex buffers? All the examples I've seen so far do something like this float data[] = { //position v1x, v1y, v1z, v2x, v2y, v2z, ... vnx, vny, vnz, //color c1r, c1g, c1b, c2r, c2g, c2b, ... cnr, cng, cnb, }; GLuint buffname; glGenBuffers(1, &buffname); glBindBuffer(GL_ARRAY_BUFFER, buffname); glBufferData(GL_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW); And the drawing is done something like this: glBindBuffer(GL_ARRAY

问题 The title says everything, but just to be clear I'll add some extra words. In this case, resize means: getting more storage space at the end of the old vbo saving the old data at the front (hopefully not copying, but at least not on CPU side, meaning the driver should handle this) EDIT As to explain some more details and justify my question: I will store data of (in forehand) unknown size to the VBO but I only know an upper limit that is a very rough estimation (10 - 100x as much or even more

问题 I've been trying to convert an OBJ parser that I wrote previously that used display lists to use VBOs instead, and have attempted to see if I could figure out the issue myself without any outside help, but now I think I have been looking at the code too long and am unable to find any errors. This is an Android App, through OpenGLES 2.0, and I end up with some triangles up on the screen, but not in the correct places at all. I have a feeling that my attempt to get all of the elements of each

问题 I am trying to create a VBO for a simple rectangle. The GL is set up to use the core profile (GL: 3.2, GLSL: 1.5, inside an NSView in Cocoa). I spent hours trying to figure out how to draw a simple rectangle in OpenGL. It seems really hard to find any decent tutorials on the core profile. The best I could find was this tutorial. I adapted it to my needs and came up with the following code: GLfloat vertices[] = { 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0 }; glGenBuffers

问题 I'm trying to convert a program using draw lists, which are deprecated in OpenGL 3.0+, to use either vertex arrays or VBOs, but I'm not finding any examples of how to do the conversion. What's in the program now is this (happens to be Python, but really what I'm interested in is the appropriate OpenGL calls---it could just as well be C++, for example): dl = glGenLists(1) glNewList(dl, GL_COMPILE) glBindTexture(GL_TEXTURE_2D, texture) glBegin(GL_QUADS) glTexCoord2f(0, 0) glVertex2f(0, 0)

问题 When should i call glDeleteBuffersARB ? Should I do it when application ends? Can I somehow automatize the process of deletion vertex buffer object? For instance something like smart_ptr does. 回答1: Never. You should never call glDeleteBuffersARB . Buffer objects have been core GL functionality for upwards of a decade now; if you're still using the ARB-suffixed extensions functions, STOP . If you're follow a tutorial that uses them, again STOP ; it's clearly too old to be useful. Now, when

问题 I have a terrain mesh stored in a VBO. The mesh is a grid composed of right triangles. In other words, it looks like a rectilinear grid with diagonals. The width and height of the mesh are known, so it's easy to calculate the vertex indices for a given XY or vice-versa. The terrain mesh will be editable. My question concerns rebuffering the vertex data when the terrain is edited. I will be able to determine the rectangular region of vertices that are dirtied by any edit operation, so

问题 I am trying to use VBOs to draw my model in in C# using OpenTK. In my online research I read in many places that it is good practice to make the size of the interleaved data structure an exact multiple of 32 bytes, so I coded up the following: [Serializable] [StructLayout(LayoutKind.Sequential)] public struct Byte4 { public byte R, G, B, A; public Byte4(byte[] input) { R = input[0]; G = input[1]; B = input[2]; A = input[3]; } public uint ToUInt32() { byte[] temp = new byte[] { this.R, this.G,

问题 I am currently working on a small 2D game with LWJGL. I use line strips to draw randomly generated grass. Each of the blades consists of 6 points and has a random green color. The problem I face: To fill the ground with a gapless layer of grass, I need approx. 400 line strips... In addition, every line strip has to be shifted, when the player moves around and should (optionally) wave in the wind. Therefore I need to change the data of 400 vbos every frame. Is there any way to accelerate these