glsl

问题 In OpenGL you can linearize a depth value like so: float linearize_depth(float d,float zNear,float zFar) { float z_n = 2.0 * d - 1.0; return 2.0 * zNear * zFar / (zFar + zNear - z_n * (zFar - zNear)); } (Source: https://stackoverflow.com/a/6657284/10011415) However, Vulkan handles depth values somewhat differently (https://matthewwellings.com/blog/the-new-vulkan-coordinate-system/). I don't quite understand the math behind it, what changes would I have to make to the function to linearize a

问题 I've been searching the web for a while now and did not find the correct answer yet. I found the list of uniform types THREE.js uses, and I think the following code should be correct. At the last line I define an uniform array of Vector2. uniforms: { "center": { type: "v2", value: new THREE.Vector2( 0.5, 0.5 ) }, "aspectRatio": { type: "f", value: null }, "radius": { type: "f", value: 0.1 }, "pointList": { type: "v2v", value: [] }, }, In my js script I pass this array as follows. This should

问题 I am trying to implement Blur effect in my game on mobile devices using GLSL shader. I don't have any former experience with writing shaders. And I don't understand if my shader is enough good. Actually I have copyied the GLSL code from a tutorial and I don't know it this tutorial is for vivid demo or also can be used in practice. Here is the code of two pass blur shader that uses Gaussian weights (http://www.cocos2d-x.org/wiki/User_Tutorial-RenderTexture_Plus_Blur): #ifdef GL_ES precision

问题 If I create a double-precision vertex buffer, for example: GLuint vertBuffer, spanBuffer, spanCount, patchSize, program; // already setup glUseProgram (program); glEnableClientState (GL_VERTEX_ARRAY); glBindBuffer (GL_ARRAY_BUFFER, vertBuffer); glVertexPointer (3, GL_DOUBLE, 0, 0); glPatchParameteri (GL_PATCH_VERTICES, patchSize); glBindBuffer (GL_ELEMENT_ARRAY_BUFFER, spanBuffer); glDrawElements (GL_PATCHES, spanCount * patchSize, GL_UNSIGNED_INT, 0); How do I access the double precision

问题 I defined a struct for light parameters which contains two vectors. The struct is defined in both C++ and GLSL in an analogous way (note: QVector3D encapsulates 3 float s, not double s): C++ host program: struct LightParameters { QVector3D pos; QVector3D intensity; }; Fragment Shader: struct LightParameters { vec3 pos; vec3 intensity; }; In the fragment shader, I also define the following uniforms. The numbers of lights is limited to 8, so the uniform array has a constant size (but only

问题 I have written code to render my scene objects to a cubemap texture of format GL_DEPTH_COMPONENT and then use this texture in a shader to determine whether a fragment is being directly lit or not, for shadowing purposes. However, my cubemap appears to come out as black. I suppose I am not setting up my FBO or rendering context sufficiently, but fail to see what is missing. Using GL 3.3 in compatibility profile. This is my code for creating the FBO and cubemap texture: glGenFramebuffers(1,

问题 Is it possible to achieve an transparency effect where fragments with alpha lower than 0.5 are discarded and fragments with alpha higher than 0.5 are rendered rendered opaque? From what I've read, glEnable(GL_ALPHA_TEST); glAlphaFunc(GL_GREATER, 0.5); would be what I'm looking for but unfortunately, AlphaFunction is not defined in WebGL. Is there a workaround? My problem is, that transparent fragments write into the depth buffer and thus prevent farther fragments from beeing rendered: alpha

问题 I have implemented CPU code that copies a projected texture to a larger texture on a 3d object, 'decal baking' if you will, but now I need to implement it on the GPU. To do this I hope to use compute shader as its quite difficult to add an FBO in my current setup. Example image from my current implementation This question is more about how to use Compute shaders but for anyone interested, the idea is based on an answer I got from user jozxyqk, seen here: https://stackoverflow.com/a/27124029

问题 I'm trying to create a grid of points by calculating vertex positions dynamically, based on their index in the array of vertices sent to the shader. Is there an equivalent of the gl_VertexID variable that I can call from within my shader? Or another way of accessing their position in the array without having to send more data to the GPU? Thank, Josh. Here's my vertex shader: attribute vec4 vertexPosition; uniform mat4 modelViewProjectionMatrix; vec4 temp; uniform float width; void main() {

问题 I'm trying to create a grid of points by calculating vertex positions dynamically, based on their index in the array of vertices sent to the shader. Is there an equivalent of the gl_VertexID variable that I can call from within my shader? Or another way of accessing their position in the array without having to send more data to the GPU? Thank, Josh. Here's my vertex shader: attribute vec4 vertexPosition; uniform mat4 modelViewProjectionMatrix; vec4 temp; uniform float width; void main() {