glsl

My understanding is that you can convert gl_FragCoord to a point in world coordinates in the fragment shader if you have the inverse of the view projection matrix, the screen width, and the screen height. First, you convert gl_FragCoord.x and gl_FragCoord.y from screen space to normalized device coordinates by dividing by the width and height respectively, then scaling and offsetting them into the range [-1, 1]. Next you transform by the inverse view projection matrix to get a world space point that you can use only if you divide by the w component. Below is the fragment shader code I have

The effect I want to achieve is vertex color with sharp contours. So inside the triangle the fragment shader should use the color of whatever vertex is closest to that fragment. Now when thinking about it, the only solution I can come up with is assigning tex coords 1,0,0 0,1,0 and 0,0,1 to the three vertices and have 2 (reoordered) duplicates of the vertex color array and then choose from the color aray of which the corresponding tex coord is highest. This method would at least add 9 more floats to each vertex. Which will slow down the application as my meshes are changing quit often and

I'm just a noob to GLSL and don't know how to do this in GLSL. What I trying to do is making alpha value to 1 on center of sphere and drop gradually on outer. So I made a prototype using Blender node editor and that's how I did. Now I am trying to do this in glsl. Maybe i can use gl_Normal to replace "normal on Geometry" on Blender. (Though it's removed after version 140, my final goal is just "make" it, so ignore that.) And there are also dot function to calculate "dot product on vector math" on glsl. Now i need is "View vector of camera data" and "ColorRamp". I think "ColorRamp" can be done

Using below code I can display an image in openGL control. Which is in rectangular shape. Now I want to project top and bottom area of this rectangular to a cylindrical shape.I mean need to perform a rectangular to cylidrical projection on openGL. How can I achieve this? private void CreateShaders() { /***********Vert Shader********************/ vertShader = GL.CreateShader(ShaderType.VertexShader); GL.ShaderSource(vertShader, @"attribute vec3 a_position; varying vec2 vTexCoord; void main() { vTexCoord = (a_position.xy + 1) / 2; gl_Position = vec4(a_position, 1); }"); GL.CompileShader

I was wondering if there was a way to tell if a vertex attribute is enabled from within a vertex shader? I know that if the vertex attribute is disabled all the values will be treated as 0.0, so I could do a test like the following: if (attribute == 0) { // Do something different to normal. } else { // Use the attribute. } But this has the obvious problem for the case that the attribute is enabled and the value is just set to 0 (it will be treated as if it's disabled)! The other solution would be to just use a uniform variable that states whether or not to use the attribute, but I wondered if

I know that iPhone uses OpenGL ES 2.0, but I don't know the version of the underlying language GLSL. Is it 1.3, 1.4, 2.0, or other? Ok, I found it myself, thanks to the _____VERSION_____ predefined macro. The GLSL ES specification used is the 1.0, which is based on the GLSL version 1.20. The OpengGL ES 2.0 and GLSL ES 1.0 specifications are available for download at http://www.khronos.org/registry/gles/ . Angus Forbes printf("GLSL Version = %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION)); printf("GL Version = %s\n", glGetString(GL_VERSION)); On IOS 5.1, this prints out: GL Version = OpenGL ES

I am trying to find information or examples that I can use to create a smudge/liquify effect that continuously animates back to the original state. Initially I was looking at using three.js or pixi.js to render some text and then use mouse events and ray casting to drag the mesh out of position, the closest thing I have found is this. https://codepen.io/shshaw/pen/qqVgbg let renderer = PIXI.autoDetectRenderer(window.innerWidth, window.innerHeight, { transparent: true }); I think that ideally I would render the text as an image and then the smudge effect would be applied to the pixels and they

...because the floats seem to be coming out fine, but there's something wrong with the ints. Essentially I have a struct called "BlockInstance" which holds a vec3 and an int . I've got an array of these BlockInstances which I buffer like so (translating from C# to C for clarity): glBindBuffer(GL_ARRAY_BUFFER, bufferHandle); glBufferData(GL_ARRAY_BUFFER, sizeof(BlockInstance)*numBlocks, blockData, GL_DYNAMIC_DRAW); glVertexAttribPointer(3,3,GL_FLOAT,false,16,0); glVertexAttribPointer(4,1,GL_INT,false,16,12); glVertexAttribDivisor(3,1); glVertexAttribDivisor(4,1); And my vertex shader looks like