vbo

问题 I'm trying to render multiple objects in OpenGL using multiple VAO's and VBO's. To render multiple objects using the same vertices I've done it, but what I want to do is to use different vertices for each object, for example to draw a square and a circle. For a square I only need 6 vertices but for circle I need 360. I have error with reading or creating the shaders. Here is the Vertex Shader: #version 330 core layout (location = 0) in vec4 position; uniform mat4 model; uniform mat4 view;

问题 I have my VBO using single buffer at the moment, it has vertex, texcoord and color elements. Now, is it possible to update efficiently only the texcoords without updating the vertex/color as well? It should be the same efficiency as having separate buffers updated. 回答1: You can map a specific range of your VBO into user memory using glMapBufferRange. Of course, if your vertex, color and texcoord data are interleaved, it will be equivalent to a glMapBuffer. EDIT: If your VBO is: [XYZ XYZ XYZ

问题 I'm currently using glDrawElements to render using multiple VBOs (vertex, color, texture, and index). I've found that very few vertices are shared, so I'd like to switch to glDrawArrays, and a single interleaved VBO. I've been unable to find a clear example of 1) creating an interleaved VBO and adding a quad or tri to it (vert, color, texture), and 2) doing whatever is needed to draw it using glDrawArrays. What is the code for these two steps? 回答1: Off the top of my head: //init glBindBuffer

问题 In OpenGL 4.4 there was a nice extension added: ARB_buffer_storage How does persistent buffers work (or might work) - using MAP_COHERENT_BIT and MAP_PERSISTENT_BIT set ? Is there some special intermediate buffer? Why it can be usually faster than normal mapped buffers? 来源： https://stackoverflow.com/questions/27777368/how-does-persistent-mapped-buffers-work-in-opengl

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed last year . I have a model designed in Blender that i am going to render, in my game engine built using opengl, after exporting it to collada. The model in blender is divided into groups. These groups contains vertices normals and textures with there own index. is it a good thing to do if i

问题 I have recently migrated from a 32bit environment to a 64bit one, and it has gone smoothly apart from one problem: glMultiDrawElements uses some arrays that do not work without some tweaking under a 64bit OS. glMultiDrawElements( GL_LINE_LOOP, fCount_, GL_UNSIGNED_INT, reinterpret_cast< const GLvoid** >( iOffset_ ), mesh().faces().size() ); I am using VBOs for both the vertices and vertex indices. fCount_ and iOffset_ are arrays of GLsizei . Since a buffer is bound to GL_ELEMENT_ARRAY_BUFFER

问题 So I've been trying to teach myself to use VBOs, in order to boost the performance of my OpenGL project and learn more advanced stuff than fixed-function rendering. But I haven't found much in the way of a decent tutorial; the best ones I've found so far are Songho's tutorials and the stuff at OpenGL.org, but I seem to be missing some kind of background knowledge to fully understand what's going on, though I can't tell exactly what it is I'm not getting, save the usage of a few parameters. In

问题 So I've been trying to teach myself to use VBOs, in order to boost the performance of my OpenGL project and learn more advanced stuff than fixed-function rendering. But I haven't found much in the way of a decent tutorial; the best ones I've found so far are Songho's tutorials and the stuff at OpenGL.org, but I seem to be missing some kind of background knowledge to fully understand what's going on, though I can't tell exactly what it is I'm not getting, save the usage of a few parameters. In

问题 I'm creating a CAD-like app (Qt-based), it will be a multiple document interface and each document will contain about 5 viewports (derived from QGLWidget). As such I need my flat shader to be shared across the entire application, and then the 3D assets (models stored as VBOs) to be shared across each document i.e. the 5 viewports. I thought as long as I shared around the shader program and VBO GLuint addresses all will automagickly work - it doesn't. I think because each viewport/context has

问题 I am a desktop GL developer, and I am starting to explore the mobile world. To avoid misunderstandings, or welcome-but-trivial replies, I can humbly say that I am pretty well aware of the GL and GL|ES machinery. The short question is: if we are using GL|ES 2.0 in a shared memory architecture, what's the point behind using VBOs against client-side arrays? More in detail: Vertex buffers are raw chunks of memory, the driver cannot in any way optimize anything because the access pattern depends