A programming language for OpenGL shaders.

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Shaders are recompiled on every uniform change

In my game I'm using shaders to change the color of objects depending on their health. I'm passing floats from my jME3 project to the shaders by using material.setFloat("UniformName", uniformValue). ...
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3 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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122 views

Skeletal animation in OpenGL

I'm using Assimp to do skeletal animation in my OpenGL application. I used Blender to export this one-boned model to a COLLADA file: The model has only one bone, called arm bone, that controls the ...
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1answer
57 views

How to only render fragments with Z from 0 to 1 in OpenGL?

I have been using OpenGL for a year now, but I just recently found out that OpenGL only clips vertices when the absolute value of the x,y or z coordinate is less than the absolute value of w ...
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1answer
41 views

how change branching logic to math equivalent glsl? [closed]

im totally newbie and this just for fun afaik lot of best practice suggest to minimize usage of branching. can you help me optimize below glsl especially on branch part? ( target 120 ) the bgcolor ...
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39 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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1answer
27 views

Can glsl main() have params or return a value?

I haven't ever seen anyone declare main as anything but void main() or void main(void) but I'm curious, is it possible to have a parameter or return value?
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1answer
91 views

Shader - Color blending

I would like to know how to blend colors in a specific way. Let's imagine that I have a color (A) and an other color (B). I would like to blend them in such a way that if I choose white for the (B) ...
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1answer
37 views

Modern OpenGL Texture Displaying Incorrectly [closed]

I've been working with this code and have simplified it to the most basic form possible, and even then I cannot get a texture to display properly at all. Here is the code: ...
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1answer
52 views

Shader - Convert vector into scalar

I am trying to convert a half3 as a simple half but I am facing an issue. As for an example half3(1, 0, 0) give me white but half3(0, 1, 0) gives me black. How can I convert properly a half3 to a ...
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60 views

How to handle the birth and death of particle without reading from the buffer

I've implemented a simple particle system where each particle has a position, velocity, age and lifespan stored in different SSBOs. Most of the data including all the position, velocity and age is ...
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28 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]) ...
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1answer
72 views

2D Hidden Object Silhouette Shader

Right now I am not using any depth information in my engine, but I just found out that it would be neat to be able to render the silhouette of important game objects that are "behind" something with a ...
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2answers
63 views

Problems with Rotation Matrices on Certain Axes

Here is what my rotation matrix looks like: public Matrix4f initRotation(float x, float y, float z) { Matrix4f rx = new Matrix4f(); Matrix4f ry = new Matrix4f(); Matrix4f rz = new ...
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58 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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2answers
46 views

Rectangular area light illuminance - colour banding

I'm currently working on an implementation of rectangular area lights but I am having some issues with the illuminance calculation, which gives me serious colour banding across the entire lit area. ...
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43 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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2answers
105 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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24 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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1answer
114 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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76 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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31 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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37 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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1answer
125 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
85 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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23 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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67 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
127 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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36 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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28 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
165 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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59 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
94 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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90 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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48 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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3answers
134 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
68 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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41 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
123 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); ...
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1answer
121 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
71 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
73 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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38 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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44 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
90 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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87 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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77 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
59 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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69 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
124 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 ...