vao

I have a problem validating my shader program in LWJGL/OpenGL 3. I read the documentation, but I can't seem to find a reason why a VAO is needed when calling glValidateProgram. int program = glCreateProgram(); int vertexShader = glCreateShader(...); int fragmentShader = glCreateShader(...); // ... vertex and fragment shader loading, compiling, errorchecking ... glAttachShader(program, vertexShader); glAttachShader(program, fragmentShader); glBindAttribLocation(program, 0, "position"); glBindAttribLocation(program, 1, "color"); glLinkProgram(program); glDetachShader(program, shader);

Suppose I set up two VAOs, using the new (as of OpenGL 4.3) glBindVertexBuffer mechanism: glGenVertexArrays(1, &vaoIndex0); glGenVertexArrays(1, &vaoIndex1); ... glBindVertexArray(vaoIndex0) glBindVertexBuffer(bindingIndex0, ...) glEnableVertexAttribArray(0) glVertexAttribFormat(0, ...) glVertexAttribBinding(0, bindingIndex0) ... glBindVertexArray(0) ... glBindVertexArray(vaoIndex1) glBindVertexBuffer(bindingIndex1, ...) glEnableVertexAttribArray(0) glVertexAttribFormat(0, ...) glVertexAttribBinding(0, bindingIndex1) ... glBindVertexArray(0) And suppose the two are independent, except insofar

I have the following code which should simply draw a green triangle to the screen. It is using Vertex Array Objects and index buffers to draw and has the simplest shader I could make. At first I was not using index buffers and was simply making the draw call with glDrawArrays which worked fine but when I change it to use glDrawElements then nothing is drawn to the screen (it is entirely black). from OpenGL.GL import shaders from OpenGL.arrays import vbo from OpenGL.GL import * from OpenGL.raw.GL.ARB.vertex_array_object import glGenVertexArrays, \ glBindVertexArray import pygame import numpy as

When created, do VAOs track just VBO indices (via glBindVertexBuffer ), or also which VBO names are bound to those indices? If I specify a binding index of, say, 0 using glVertexAttribBinding during VAO creation, can I bind a different VBO to index 0 just prior to a draw call and have it use the contents of that VBO, or will it always use whatever VBO was bound to index 0 at the time the VAO was created? I ask because a lot of examples I find precede calls to glVertexAttribFormat and glVertexAttribBinding with a call to glBindVertexBuffer , which should not be necessary if the VAO tracks only

I am writing an OpenGL3+ application and have some confusion about the use of VAOs. Right now I just have one VAO, a normalised quad set around the origin. This single VAO contains 3 VBOs; one for positions, one for surface normals, and one GL_ELEMENT_ARRAY_BUFFER for indexing (so I can store just 4 vertices, rather than 6). I have set up some helper methods to draw objects to the scene, such as drawCube() which takes position and rotation values and follows the procedure; Bind the quad VAO. Per cube face: Create a model matrix that represents this face. Upload the model matrix to the uniform