glsl

问题 I'm using the compute shader bound with a SSAO. And I use the following structure in the compute shader: struct Particle { vec4 pAnds; vec3 velocity; float lifespan; float age; }; layout (std430, binding = 0) buffer members_in { Particle particle[]; } input_data; yet it seems that the memory block allocated for each of these data structure is not equal to (4 + 3 + 1 + 1) * 4. And I also tried another one: struct Particle { vec4 pAnds; vec3 velocity; float lifespan; }; This time it worked fine

问题 I'm making a simple WebGL demo. I have a simple vertex shader that takes two attributes and some uniforms. Here is the code: attribute vec3 v_position; attribute vec3 v_normal; uniform mat4 mvMatrix; uniform mat4 pMatrix; uniform mat3 normalMatrix; uniform vec3 lightPosition; // Color to fragment program varying vec3 transformedNormal; varying vec3 lightDir; void main(void) { // Get surface normal in eye coordinates transformedNormal = normalMatrix * v_normal; // Get vertex position in eye

问题 I drawing a set of quads. For each quad I have a defined color in a vertex of it. E.g. now my set of quads looks like: I achive such result in rather primitive way just passing into vertex shader as attribute color of each vertex of an quad. My shaders are pretty simple: Vertex shader #version 150 core in vec3 in_Position; in vec3 in_Color; out vec3 pass_Color; uniform mat4 projectionMatrix; uniform mat4 viewMatrix; uniform mat4 modelMatrix; void main(void) { gl_Position = projectionMatrix *

问题 For Luminace histogram calculation I have used the code from the project GPU image ios by Brad Larson. He has used blending for Histogram calculation. Attaching the Vertex and Fragment shader Vertex shader #version 300 es in vec4 position; out vec3 colorFactor; const vec3 W = vec3(0.299, 0.587, 0.114); void main() { float luminance = dot(position.xyz, W); colorFactor = vec3(1.0, 1.0, 1.0); gl_Position = vec4(-1.0 + (luminance * 0.00784313725), 0.0, 0.0, 1.0); gl_PointSize = 1.0; } ; Fragment

问题 I'm beginning to understand how to implement a fragment shader to do a 1D LUT but I am struggling to find any good resources that tell you how to make the 1D LUT in C++ and then texture it. So for a simple example given the following 1D lut below: Would I make an array with the following data? int colorLUT[255] = {255, 254, 253, ..., ..., ..., 3, 2, 1, 0}; or unsigned char I guess since I'm going to be texturing it. If this is how to create the LUT, then how would I convert it to a texture?

问题 i'm trying to learn the basics of OpenGL, but i have a Problem with setting up the transformation matrices. I made the model, view and projection matrices, but i have a problem sending them to my vertex shader. Here is the code: //Set up MVP glm::mat4 model = glm::mat4(); GLint uniModel = glGetUniformLocation(program, "model"); glUniformMatrix4fv(uniModel, 1, GL_FALSE, glm::value_ptr(model)); glm::mat4 view = glm::lookAt( glm::vec3(2.5f, 2.5f, 2.0f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0

问题 In my open source project I have setup a deferred rendering pipeline using Qt3D. So far so good, but now I'd like to move forward by adding spotlights projection volume. (e.g. as if there is smoke in the scene) Like this: The fragment shader I'm using is at the end of the question. I've read that for each fragment I should do ray marching from the light position and find the intersections with a cone, but I have no idea how to translate this into GLSL. I can easily add a uniform with the

问题 I was reading this tutorial on MSAA in deferred shading, from 28byteslater.com. It says that in explicit multisampling we can access a particular sample. Could not we do the same from a regular texture that was bound to GL_TEXTURE_2D_MULTISAMPLE for instance? This was the shader code that I used to use earlier for accessing individual samples (without using explict multisampling): uniform sampler2DMS Diffuse; ivec2 Texcoord = ivec2(textureSize(Diffuse) * In.Texcoord); vec4 colorFirstSample =

问题 I'm trying to write a shader that uses many bit operations. In fact they are supported since glsl 1.30, but I'm only on OpenGL 2.1. Is there any way to use bit operations with my OpenGL version? 回答1: All SM3 compatible (~OpenGL 2.1) hardware supports limited integer functionality. This is usually done by emulating integers with floats and does not include bit operations. For bit operations, you need either GLSL 1.3 or EXT_gpu_shader4. If the reason that you have only OpenGL 2.1 is that your

问题 I have a very simple program that maps a dummy red texture to a quad. Here is the texture definition in C++: struct DummyRGB8Texture2d { uint8_t data[3*4]; int width; int height; }; DummyRGB8Texture2d myTexture { { 255,0,0, 255,0,0, 255,0,0, 255,0,0 }, 2u, 2u }; This is how I setup the texture: void SetupTexture() { // allocate a texture on the default texture unit (GL_TEXTURE0): GL_CHECK(glCreateTextures(GL_TEXTURE_2D, 1, &m_texture)); // allocate texture: GL_CHECK(glTextureStorage2D(m