A programming language for OpenGL shaders.

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791 views

Transforming normal vector in GLSL

I'm looking at a basic diffuse light shader here http://en.wikibooks.org/wiki/GLSL_Programming/Unity/Diffuse_Reflection. Diffuse light needs the normal vector in eye-space, so that it can dot it with ...
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1answer
445 views

(WebGL) Point light per-fragment issue

I'm using an FPS-like camera, this is the code: CAMERA mat4.identity(mat.mvMatrix); mat4.rotate(mat.mvMatrix,degToRad(-camera.pitch),[1,0,0]); ...
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1answer
230 views

Combine framebuffer-textures to default framebuffer

I know frame-buffers are not textures themselves, but they do contain a texture, given they are set up correctly, which I believe mine are, as: (status == GL_FRAMEBUFFER_COMPLETE) returns true. ...
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1answer
245 views

Why do the ALPHA channel in TGA is not visible?

Good morning GDSE, I am loading a TGA using loadTGA function found in superbible 4th edition source code. Here is how the image looks in Gimp You can see I have enabled alpha channel in Gimp, I ...
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1answer
475 views

fragment shader directional light positioning with camera

Im trying to set up directional lighting in the fragment shader. So the direction of my light moves with the camera position. #version 150 core uniform sampler2D diffuseTex; ...
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693 views

HLSL's Tex2D for GLSL?

I am trying to port a HLSL shader to GLSL. I'm just not quite sure how to convert this line: outA += Input.Color.a * tex2D(s, Input.TexCoord.xy + float2(-4.0 * pxSz.x * blurSize,0)).a * 0.05; ...
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311 views

Creating a fragment shader to darken a white texture over time - OpenGL GLSL

So as a part of learning OpenGL, I've now decided to try and be a bit more creative with shaders, as part of a practice game I'm making using C/OpenGL. I'm completely new when it comes to working ...
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471 views

GLSL: Strange light reflections

According to this tutorial I'm trying to make a normal mapping using GLSL, but something is wrong and I can't find the solution. The output render is in this image: in this image is a plane with ...
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313 views

Get world-position in Vertex shader

I'm wondering how I can get the final position of a vertex. I use glTranslate in my render code, and I'm not getting the world-coordinates correct. My world is devided in chunks and my position get's ...
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254 views

bump mapping with 2 normal maps

I was wondering if its actually possible to do bump mapping with 2 normal maps... I have tried doing it this way however I get a function overload on max and dot. uniform sampler2D n_mapTex; uniform ...
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449 views

texture won't move OpenGL ES 2.0

I want be able to move my texture in GLSL I have set my texture to wrap S and wrap T but not sure why it wont move my fragment shader looks like this at the moment uniform sampler2D n_mapTex; ...
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304 views

How do I pass textures into a fragment shader in Slick?

I've written a shader that uses three different textures, tex0, tex1, and tex2. I can load it into Slick and successfully display it, but I can't figure out how to set the three different textures. ...
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430 views

OpenGL ES 2. How do I Create a Basic Fading Streak Effect?

For the iPad app I am writing using OpenGL ES 2 I have a single quad - shaded using GLSL - that is dragged around the screen. Very basic. This works fine. But is rather boring. I want to increase ...
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1answer
974 views

How to convert Maya shaders and Renderman shaders to GLSL?

I know this 2 products but i have never used them for production, since I have a bunch of cool shaders i would like to use them under OpenGL with GLSL but i don't know where to start. If it's not ...
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1k views

Making a surface transparent from blackness of texture

I am making a "halo" shader in unity using GLSL. And I've come to a roadblock. What I need to do is take a texture, like the following, and make it transparent according to the darkness of it. And I ...
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1answer
968 views

CG/CGFX to GLSL

So, I'm making the painful move from my beloved XNA to OpenTK, and I'm stuck: Since I've got a LOT of existing shaders written in HLSL, NVidia's CG compiler seems like a natural way to minimize the ...
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1answer
731 views

Help understand GLSL directional light on iOS (left handed coord system)

I now have changed from GLKBaseEffect to a own shader implementation. I have a shader management, which compiles and applies a shader to the right time and does some shader setup like lights. Please ...
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18 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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25 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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15 views

Perspective divide: Why use the w component? [duplicate]

In OpenGL, I have read that a vertex should be represented by (x,y,z,w), where w = z. This is to enable perspective divide, whereby (x,y,z) are divided by w in order to determine their screen position ...
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1answer
16 views

Passing data into a vertex shader for perspective divide

In OpenGL and GLSL, I am just learning about perspective projection and the vertex shader. However, I am a little confused about what data actually needs to be passed to the vertex shader, and what ...
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37 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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18 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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1answer
49 views

Create a “genie” effect in fragment shader GLSL

I have tried a while now to create a genie effect on a scrolling plane to emulate the background/floor from the Mad Hatter fight in Adventures of Batman and Robin (SEGA). Judging the way the 16 bit ...
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33 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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30 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 ...
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2answers
63 views

GLSL Fragment shader lighting lambert term

Just a simple question: Should I or should i not normalize the SurfaceToLight vector to calculate the lambert term on a GLSL lighting shader? I mean, here: vec3 CalculateLights ( void ) { vec3 ...
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1answer
50 views

OpenGL Shaders Ignored

I have been following this tutorial to try and start learning OpenGL. However, upon compiling my code, my triangle turns out to be black. At first I thought that there was something wrong with the ...
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35 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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73 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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1answer
68 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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51 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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58 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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89 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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61 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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54 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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65 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
331 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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28 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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77 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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34 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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127 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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99 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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0answers
49 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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0answers
52 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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118 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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95 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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58 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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145 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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50 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 ...