A programming language for OpenGL shaders.

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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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1answer
32 views

Blending vs Texture Sampling

I don't think this question has been asked before as I couldn't find any information about this on the internet. Lets say I want to blend two textures together: A texture containing the result of ...
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42 views

WebGL Multiplayer Game - Direction Needed (Shaders) [on hold]

I've started looking into making a multiplayer game for web browsers. I started with a book "WebGL Up and Running" and it has lead me to be more curious about more detailed aspects of OpenGL. In ...
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9 views

change position/orientation of a bone using assimp

I have been using assimp to import rigged models and animations. I followed this tutorial for skeletal animation and I have got it done properly. The part that I am trying to do now is to orient a ...
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45 views

How to generate a RGB * a texture for a glow effect in GLSL?

I would like to create a glow effect in GLSL, there is a tutorial that explains how we multiply RGB * a : I have some questions : is it an operation that is in a fragment shader, where RGBa is ...
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46 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 ...
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14 views

Can i use shaders in allegro without opengl?

I'm currently learning opengl but it seems quite complicated so i considered using some library like sdl or allegro. I noticed that allegro has some built in functions to create and attach shaders. ...
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20 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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39 views

OpenGL Shader Storage Buffer Objects array length problem

Ok guys, I think I have a very strange problem. I have an old laptop, but its HD 6370M currently supports opengl 4.4, so i decided to learn how to use some new features of this platform, so after ...
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1answer
55 views

How to use a buffer in GLSL to do a LUT-lookup?

I am currently on a medical application which needs different kinds (up to totally individual) lookup tables (LUT) for image display. And this done with 10bit finish. So it is most of the time ...
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15 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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1answer
59 views

Calling Shader Functions Inside Other Shaders

I'm new to OpenGL and GLSL, and bit confused about calling conventions of shader functions. I'm trying to implement various procedural noise algorithms in GLSL. I'd like to have separate files for ...
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1answer
85 views

Dot based light mask with shader on sprites

So I have a scene, completely based on 2D sprites. I want to render "light sources" into a seperate frame buffer (so mostly dots around, for example, the centre of a flame) and then render that frame ...
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18 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: ...
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27 views

Strange result, when changing variable name

I have no idea, what is going on. The mat4 xxx is the cause. Renaming it to "bones"/"bone_transfromations" etc. won't work it gives me an error. Renaming it to "test" works perfectly fine... This is ...
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1answer
126 views

What are the advantages of tangent space shading/lighting, and what about attenuation?

In several topics here it was suggested by people that doing lighting in tangent space is better than doing it in world space. Right now I am doing it in camera space, but it's really similar to world ...
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39 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 ...
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2answers
58 views

glsl uniform int as index of const array

I have a const array that define a few materials for directionnal light. I'd like to change the material using an uniform int as index of that array. Doing that leads to severe framerate drop. I know ...
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57 views

loading a model, which has multiple meshes using assimp

I have been using Open Asset Import library(assimp) along with OpenGL API to load and render 3D models. I followed some tutorials and have got the output as expected. But, I have failed to understand ...
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36 views

Achieve SSAO with deferred rendering,GLSL

I'm trying to add SSAO effect to my engine and it doesn't look as it should. To achieve this effect I based on this article. I'm using also deferred renderer so I entered some modifications: ...
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2answers
69 views

Passing array to uniform in glsl error

Here is my attemps to pass array to uniform array: struct Vector{ float x,y,z; } float threshold[2] = { 0.5, 0.25 }; Vector *kernel = new Vector[_kernel_size]; // _kernel_size==16 // fill kernel ...
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1answer
57 views

OpenGL Post Processing Introducing Artifacts on Certain Systems

Playing around with God-Rays in my framework, I was greeted with the following artifacts on my laptop: The artifacts themselves act almost like noise, flickering around the image rapidly. They also ...
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32 views

Motion Blur (as per GPU gems article) only considers camera rotation, not translation

I am following this article and have implemented it exactly as described: http://http.developer.nvidia.com/GPUGems3/gpugems3_ch27.html The problem is that things are only blurred when the camera is ...
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2answers
99 views

How can I optimize these GLSL bitwise operations?

I need the following part of my vertex shader simplified. Sb=Sb|((gl_VertexID&(128+1))<<9); Sb=Sb|((gl_VertexID&(512+4))<<6); Sb=Sb|((gl_VertexID&(2048+16))<<3); ...
3
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1answer
117 views

If-clause in GLSL

I read a few thing about, that in GLSL both sides of the if-clause is executed, so do you have any idea for a workaround for this one: uniform int uses_bones; uniform mat4[] bone_transformations; ...
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1answer
43 views

OpenGL/GLSL/LWJGL return value from shader

I'm trying to do some bone animation. I don't want the whole skeleton to be loaded to the GLSL shader every time, even tough it's not needed, because one vertex is parented to one bone, not more. My ...
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1answer
57 views

Can drawing to an FBO be done purely with a depth input texture, or do I also need a color attachment?

I am trying to implement Exponential Shadow Maps and I've got it almost working. The part I am stuck on is the "optional" separable Gaussian blur of the depth map to give soft-looking shadows. I am ...
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32 views

GLSL billboarding

I want to make billboarding using GLSL. For what I've got so far it works, but not exactly the way I want. My vertex shader looks like this: #version 120 uniform float partSize; varying vec2 ...
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39 views

Trying to get the fragment shader to output a list

I am trying to figure out a way to get the Fragment Shader to output a list of gl_VertexID-s. I want to use the GPU to get a list of vertices in the viewing frustum. Is there any way I can get a ...
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1answer
79 views

Averaging normals, or tangents

I am using a library to load an obj but it doest compute the tangets for each vertex, which I need for normal mapping and pom. I computed my tangets, and bitangents, everything appears to be fine, but ...
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61 views

2D GLSL Lighting and Sprites

I'm trying to make a 2D game engine, and I really want to support ambient light as well as multiple point lights that you can define the color, intensity, radius, etc from uniforms in glsl shaders. ...
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72 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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1answer
57 views

What will happen if the argument of mix() or clamp() is above 1 or below 0?

There's two magnificent intrisincs: mix() in GLSL and clamp() in HLSL, which are used to implement linear interpolation. Let's say we have a variable: float v = ?; // where ? can be [-FLOAT_MAX, ...
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59 views

What limits the number of vertices the GPU can process per clock cycle?

I am currently experimenting with OpenGL to make my own game. I wrote some test code to see what are the limits of my GPU. I own a Geforce 840m. This essentially consists of a draw command ...
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1answer
96 views

Java, Crashing with a Shader on Intel HD Graphics

I just got a new computer (Acer Aspire ES1-311) which has an integrated Intel HD Graphics card, and I noticed that this fisheye shader crashes my game (LibGDX game, VM Crash): varying vec2 ...
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1answer
60 views

Getting the real fragment depth in GLSL

I am trying to write a simple GLSL shader that just renders the real (not normalized) depth of a fragment as a floating point value. So far, I've figured out how to get the depth of a vertex, and ...
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57 views

SFML - Rendering a torch with a fire animation [duplicate]

I have coded a 3D maze simulator in SFML using raycasting. However, I want to add a torch to the screen, so that the lighting seems more realistic. From my understanding, I would have to use ...
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1answer
88 views

How does an energy-conservative Blinn-Phong-Fresnel model work?

What is a plausible, basic equation/pseudo-code for energy-conservative Blinn-Phong shading, including Fresnel with a coloured light-source? The net gives so many alternatives that it's hard to ...
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1answer
82 views

How can I make this shader background more efficient?

I want to use a shader as a background for a mobile game. I'm using libgdx for my project. I've never written glsl before, but here's my attempt so far: http://glslsandbox.com/e#22332.13 On desktop ...
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87 views

C++ - SFML - OpenGL - GLSL - smooth waving texture

I have this shaders: Fragment: uniform float time; uniform sampler2D texture; void main() { float t = time; vec2 aux = gl_TexCoord[0].xy; // This would also make waving/deform the ...
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1answer
57 views

GLSL: Incompatible Types at Initialisation (and no available implicit conversion)

I'm recieving the following error when compiling my GLSL shader: Incompatible types in initialization (and no available implicit conversion) It occurs on line 94: int shadowMap = ...
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1answer
38 views

Opimized lineral to sRGB glsl code

Currently I use simple and ugly implementation of lineral -> sRGB transfrom float sRGB(float x) { if ( x <= 0.00031308) return 12.92*x; else return 1.055*pow(x,(1/2.4) ) - 0.055; } vec3 ...
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28 views

Encoding Floats to RGBA and Blending causing artifacts

I am using float packing to encode a float value inside a RGBA texture because I don't have access to float texture unfortunately. Here are the function I am using for encoding and decoding. inline ...
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69 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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1answer
54 views

Encoding Float to RG/RGBA and Blending

Encoding a float value inside a RG or RGBA texture is very interesting and useful but it is also become quite useless when you use blending as the result and the values might be altered because of ...
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60 views

Assimp - generate tangents and bitangents

I have started using Assmip 3.1.1 in my OpenGL application. Let's consider a simple example. Here is obj triangle model: mtllib triangle.mtl v -5.0 0.0 0.0 v 0.0 0.0 0.0 v 0.0 5.0 0.0 vn 0.0 0.0 ...
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1answer
71 views

Render model with meshes with materials and/or textures

I'm making a model class that is using Assimp in the background. I want my models' meshes to be able to have a material and an optional texture on top of that. Right now I'm doing it like this: for ...
7
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1answer
581 views

How to implement this kind of ripples with a GLSL fragment shader?

So I have already implemented the reflection part: uniform sampler2D texture; uniform vec2 resolution; uniform vec3 overlayColor; void main() { vec2 uv = gl_FragCoord.xy / resolution.xy; if (uv.y ...
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1answer
61 views

Cubemap faces rotation in GS shader

I Can't get correct rotations for cubemap faces. Thats should come to geometry shader, from camera "view" matrix I want make 6 faces for my cubemap, but seems I can't get it correctly... My first ...
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1answer
127 views

Trying to implement Camera

I'm trying to implement a Camera class in order to walk and look on the world as follow: #ifndef _CAMERA_H_ #define _CAMERA_H_ #include <glm\glm.hpp> class Camera { public: Camera(); ...