A programming language for OpenGL shaders.

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3
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75 views

How do 2D volumetric lights work?

Context So in my current project (written in Java using LWJGL / OpenGL, so GLSL for shaders) I added lighting quite a few months ago, which was already an interesting challenge, having never done ...
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87 views

Raymarching tangents

I've recently started to experiment with raymarching over on shadertoy.com. It seems common to find the normal for a distance field like so: vec3 scene_normal(vec3 p) { vec3 e = vec3(0.001, 0.0, ...
3
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99 views

OpenGL Planet Generation - Simple Matrix Issue (Planet “Spins” With Mouse)

I originally asked this question on StackOverflow & was directed here by a commenter. Im currently working on a OpenGL planet rendering. I'm using the Tessellation pipeline. So far things are ...
3
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0answers
201 views

How much is atomicAdd slower than an atomic counter?

I am considering replacing an atomic counter in my shader code with a SSBO an atomicAdd operation. What I need to know is the difference in performance of these two. I know the atomic counter executes ...
3
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406 views

Ashikhmin-Shirley model implementation: ugly result

I am trying to implement the Ashikhmin-Shirley model using these formulas: This is the GLSL 1.2 fragment shader code: uniform vec4 materialAmbient, materialDiffuse, materialSpecular; uniform ...
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48 views

Texture coordinates for custom geometry in SceneKit ios9

I am trying to texture the a custom plane shape I created in scenekit on iOS9. I need the texture to spread out and stretch over the entire surface. I have a vertex and fragment shader on an ...
2
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39 views

Virtual infinite plane in shadow map

I have a WebGL deferred rendering pipeline, where I'm rendering shadow map with VSM technique. The goal is that the scene, or model, is hovering in space, and in addition to casting shadow on itself, ...
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40 views

Understanding webgl min/mag filter texture artifacts in orthographic projection?

Summary Flickering and shimmering of image plotted on a geometry where the viewport exceeds the size of the screen. I am using an orthographic projection for the camera. In this case, it is tied to ...
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170 views

Texturing Objects in OpenGL

Using OpenGL tutorials found here, I constructed an .obj file loader as well as a texture file loader using SOIL. I have an issue with drawing a textured object. (Shown here) Assuming I created the ...
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328 views

iPhone GLSL shader dynamic branching issue

I am trying to pass an array of vec3 as uniform and then iterate through them on each pixel. The size of array varies on situations so I can't make the loop with constant number of iterations. ...
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525 views

Per fragment lighting with OpenGL 4.x tessellated model

I'm experienced with OpenGL 3+. I'm dabbling with tessellation shaders and have now got to a point where I have a nicely tessellated teapot/plane demo (quick look here) As can be seen from the ...
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315 views

Kinect User Silhouette Shader

I have this usermap from kinect's depth data (size is 320x280) and i want to display it on my game. The problem, of course it's ugly (first image) and i want to have beautiful effect like in the ...
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20 views

Best way to find line segment intersection

I am working with an OpenGL ES 2.0 shader and need to find the point of intersection between two line segments in 2D space. I receive them in terms of both coordinates of both lines. Because they are ...
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92 views

dFdx and dFdy implementation details

I've been trying to understand the details of dFdx and dFdy since I'm trying to implement MSAA on a compute shader. The best description I've found is here: dFdx and dFdy on the cpu //T is any ...
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41 views

Consistent Shadow Map Filtering

I want to filter my shadow map generated by PSSM, but the problem is that I have a inconsistent filter size. The problem is that the shadow map sources rotate to find the best fit for the camera ...
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53 views

Converting glsl shaders

I need to convert these shaders from #version 400 core to #version 130 successfully but for some reason when I do it my models are not rendering properly when I load more then one type and I cant find ...
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54 views

Set Render Target usage

I am using Unity and I have some difficulties about understanding the way Set Render Target works and how it can behave with the shaders. Is it possible to render a shader pass in multiple render ...
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36 views

glsl specular not working

ok, i'm a complete noob regarding shaders and all this, so i must be doing something really stupid, but i cannot get specular lighting to work. I've read a whole lot of different shaders on the ...
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153 views

Confused About My Code Suggesting The Normal Matrix Is Equivalent To The ModelView Matrix

I'm learning environment mapping in OpenGL by following this page. In his vertex shader, the author calculates the vertex normal in eye space with the following code: nEye = vec3(viewMatrix * ...
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142 views

glGetUniformLocation returns 23724032

as the title says, I have a problem using glGetUniformLocation call that returns, for the following code, the value 23724032. I'm writing a little engine and the draw function of my models is: void ...
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306 views

Uniform Buffer Binding-points

I believe Uniform Buffers/Blocks has been the hardest thing to grasp in OpenGL. Hopefully this will be my final issue regarding this. I have created a uniform buffer that contain data of Light ...
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114 views

Blending Lightmaps and Dynamic Texture Shadows in HLSL/GLSL

I'm using Gile[s] as my lightmapper and my engine can execute GLSL/HLSL scripts. I would like to accomplish something like this for performance reasons. I was told that this technique can only be ...
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547 views

Is it reasonable to use a 2D texture as a lookup table in GLSL

I need a lookup table in a shader. The input values would be color values and the output other color values. Something like: uniform float lut[256]; color = vec3(lut[int(color.r*255.)], ...
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501 views

implementing shadows into my 2D GLSL-based lighting system

I'm writing a lighting system in OPENGL using GLSL shaders, and I'm pretty happy with the light casting I have so far, but I'm totally stuck on casting shadows. Everything I've found online on this ...
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351 views

How to shade hair (line segments) correctly in GLSL

I render my hair geometry in line segments. The problem I have is with the correct shading of the hair. From what I've read I understood that I need the direction of the line segment and the ...
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227 views

Different way to pass uniforms to seperate draws in glMultiDrawElementsIndirect

Given OpenGL version 4.3 and GLSL 430, what would be the best way to pass a matrix to each model in a draw call to glMultiDrawElementsIndirect? I am thinking of going the way of a TBO and indexing it ...
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108 views

Texture not visible on particles

This is the first time I am working with particles (GL_POINTS) I am using kinematic equations and controlling their movement in vertex shader. I am following an example given in OpenGL 4.0 Cookbook ...
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300 views

Full screen shader causes performance hit

I basically want to have a shader run that can do something like toon shading, or grayscale the whole screen, or radial lighting. To do this, I create a new bitmap each time the display resizes that ...
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462 views

How to setup my texture cordinates correctly in GLSL 150 and OpenGL 3.3?

I'm trying to do texture mapping in GLSL 150 and OpenGL 3.3 Here are my shaders I've tried my best to get this correct as possible hopefully this is :) I'm guessing you want to know what the ...
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65 views

Modern OpenGL and SpriteBatching

I tried to find tutorials regarding SpriteBatch done in Modern OpenGL 3.0+, but failed to find any good resources so far. So can anybody please provide me a good resource/tutorial to achieve ...
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29 views

Issue with Use SSBO OpenGL

Students that use OpenGL. Do not speak English well. So please understand. There is currently a problem C++ Code Setup() : glGenBuffers(1, &ssboHandle); GLuint ssbo_binding_point_index = 0; ...
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24 views

LWJGL 3 GLSL normal problem

I have a pretty strange problem today. I started to make a 2d game yesterday, and everything was right until now. I wanted to make a lighting system, wich required me to send the vertexnormal from ...
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46 views

Unity - _LightMatrix0 and Directional Light

I am trying to access the _LightMatrix0 in a forward base pass to calculate some light point of view coordinate but it seems that the _LightMatrix0 is empty with directional light. Any idea how can I ...
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36 views

Invalid GLSL on some machines

I'm writing a game engine using OpenGL 4.3 using gcc 5, mainly to teach myself graphics programming. Initial development was on my Surface Pro 3 using mingw-w64 and worked like a charm. I've decided ...
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65 views

Color bleed ZX Speccy style

When having fun writing an imitation shader of attribute clashing on the ZX Speccy in OpenGL 3 and some fancy shaders, but I can't seem to think of an eficcient way for creating the attribute block ...
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27 views

Pass custom data rather than vertices/indices to GPU?

(For reference, I'm using OpenGL 3.3, core profile.) I'm attempting to render a decent number of 2D quads on the screen. Each quad is different, and a GLSL shader does all of the work of rendering ...
0
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0answers
22 views

Opengl - atomicMin/atomicMax issues

I have my compute shader and it compiles fine, but when linking I get an error stating "too many uniforms are used in this shader". Weirdly enough when i remove two lines of the code the shader ...
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40 views

Pass uniforms to Filter's shader

I wanna implement this shader (https://www.shadertoy.com/view/MslGWN#) in PhaserJS state. So i transformed the shader to WebGL style. I overload Phaser.Filter's update function to pass iChannel ...
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64 views

Image speeds up while moving and or rotating instead of constant speed

I'm having a problem with rotating/moving an image. I've set one of my images to rotate on it's z-axis buy updating the angle, but when I run my game, the image starts slowly starts to rotate from a ...
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0answers
38 views

OpenGL, glDrawElementsInstanced behaving differently on NVIDIA GPU than AMD

I have an AMD GPU on my desktop, AMD HD 5770. I am working on a project on my desktop for over a year. In the scene, I have instanced grass and instanced trees. Everything is working fine on desktop, ...
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46 views

ETC1 texture opacity

I'm using the cocos2d-x engine and want to support etc1 on android devices for my game. For ETC1 i'm using the mali compression tool, and GLSL. Everything is working, but I can't change the opacity ...
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38 views

GLSL lighting shader with model scale

Basically, i'm just trying to find out where to insert the model scale into the lighting calculations. Ive searched the web, but amazingly, couldn't find anything dealing with scale + GLSL. This is ...
0
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0answers
61 views

Slick2d - apply shader

I have a problem. I'm trying to apply a shader to the whole screen. Since I haven't used shaders before I don't know how to pass the texture to the shader. Everything else works... So here are the ...
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0answers
196 views

Transparency in GLSurfaceView

I'm new in game development. I have a view using GLSurfaceview and call in MainActivity. i want to make transparent that view. i have tried setZOrderOnTop() method in MainActivity and glClearColor() ...
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0answers
58 views

Shader - Simple SSS lighting issue

I am trying to create a simple subsurface scattering effect using a shader but I am facing a small issue. Look at those screenshots. The three images represents three lighting states (above surface, ...
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0answers
82 views

Shader to mask image with polygon

I'm new to graphics programming and GLSL in particular. I'm working on a 2D game and the setup is as follows: There is an image on the screen (a sprite in the game engine [Cocos2d-x if it matters]) ...
0
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113 views

Is Phong shading supposed to be so camera-angle dependent?

I'm not sure if I have a bug in my code or not. It seems like it's a bug, or at least a major shortfall. Here's two images of the same model at slightly different angles (by moving the camera): As ...
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105 views

Textured/Vertex Colored Shader fallback

I have this simple ShaderLab shader that I use for particles, among other things (it's more complicated than this but I have omitted the unnecessary bits). When I do not specify a texture, it falls ...
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32 views

converting HSLS gives error

I'm using the following parser: https://github.com/unknownworlds/hlslparser I also have the following code: /* * Bo Sun, Columbia University, All rights reserved * ...
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0answers
117 views

Invalid operation (1282) in GLSL vertex shader

My GLSL vertex shader works fine, but you if put a for loop inside or rename the uniform xxx to something else, it says the follwoing: Exception in thread "main" org.lwjgl.opengl.OpenGLException: ...