A programming language for OpenGL shaders.

learn more… | top users | synonyms

5
votes
1answer
2k views

Morph a sphere to a cube and a cube to a sphere with GLSL

I'm getting started with GLSL with quartz composer. I have a patch with a particle system in which each particle is mapped into a sphere with a blend value. With blend=0 particles are in random ...
0
votes
1answer
368 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 ...
0
votes
1answer
479 views

OpenGLES GLSL Shader attributes always bound to 0

So I have a very simple vertex shader as follows #version 120 attribute vec3 position; attribute vec3 inColor; uniform mat4 mvp; varying vec3 fragColor; void main(void){ fragColor = inColor; ...
1
vote
2answers
3k views

Passing multiple Vertex Attributes in GLSL 130

(note this question is closely related to this one however I didn't fully understand the accepted answer) To support videocards in laptops I have to rewrite my GLSL 330 shaders to GLSL 130. I'm ...
4
votes
3answers
183 views

How to read BC4 texture in GLSL?

I'm supposed to receive a texture in BC4 format. In OpenGL, i guess this format is called GL_COMPRESSED_RED_RGTC1. The texture is not really a "texture", more like a data to handle at fragment ...
0
votes
1answer
772 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 ...
1
vote
1answer
567 views

samplerCubeShadow and texture offset

I use sampler2DShadow when accessing a single shadow map. I create PCF in this way: result += textureProjOffset(ShadowSampler, ShadowCoord, ivec2(-1,-1)); result += textureProjOffset(ShadowSampler, ...
2
votes
1answer
424 views

Billboarding restricted to an axis (cylindrical)

I have succesfully created a GLSL shader for a billboarding effect. I want to tweak this to restrict the billboarding to an arbitrary axis, i.e. a billboarded quad only rotates itself about the ...
3
votes
2answers
1k views

Learning OpenGL GLSL - VAO buffer problems?

I've just started digging through OpenGL and GLSL, and now stumbled on something I can't get my head around this one!? I've stepped back to loading a simple cube and using a simple shader on it, but ...
4
votes
2answers
593 views

How Do I Raycast for a Spherical Harmonic Shader Using the iOS GPU?

I am beginning an Spherical Harmonics shader project for an iOS app I am writing. I have begun by reading this excellent in-depth paper on the subject (PDF) - http://bit.ly/aQmax3. The paper ...
2
votes
2answers
617 views

Is this a reliable method of parsing glGetShaderInfoLog()?

I want to get a list of errors and their line numbers so I can display the error information differently from how it's formatted in the error string and also to show the line in the output. It looks ...
5
votes
2answers
819 views

Geometry shader for multiple primitives

How can I create a geometry shader that can handle multiple primitives? For example when creating a geometry shader for triangles, I define a layout like so: layout(triangles) in; ...
2
votes
1answer
133 views

Uniform not being applied to proper mesh [closed]

Ok, I got some code, and you select blocks on a grid. The selection works. I can modify the blocks to be raised when selected and the correct one shows. I set a color which I use in the shader. ...
1
vote
2answers
274 views

Depth buffer values reset on change shader?

I have 2 different shaders, and when I change the shader (glUseProgram), it seems that the depth information is lost, because everything drawn with the 2nd shader appears completely on top of anything ...
3
votes
2answers
725 views

OpenGL sprites and point size limitation

I'm developing a simple particle system that should be able to perform on mobile devices (iOS, Andorid). My plan was to use GL_POINT_SPRITE/GL_PROGRAM_POINT_SIZE method because of it's efficiency ...
2
votes
4answers
530 views

What is a right datatype in C++ for OpenGL scene representation with use of GLSL

I am programming in C++ OpenGl with GLSL. Until now I have been using a data structure that is composed of std::vector filled with structures of vertexes and with their parameters (position , normal, ...
9
votes
2answers
2k views

Sorting objects before rendering

I'm trying to implement a scene graph and in all the articles i've come across there is talk about object sorting. So you'd sort your objects by "material" for example. Now untill i sat down and ...
9
votes
1answer
2k views

GLSL, all in one or many shader programs?

I am doing some 3D demos using OpenGL and I noticed that GLSL is somewhat "limited" (or is it just me?). Anyway I have many different types of materials. Some materials have ambient and diffuse color, ...
1
vote
1answer
134 views

running GL ES 2.0 code under Linux ( no Android no iOS )

I need to code OpenGL ES 2.0 bits and i would like to do this and run the programs on my desktop for practical reasons. Now, i already have tried the official GLES SDK from ATI for my videocard but ...
2
votes
2answers
853 views

Simple OpenGL program major slow down at high resolution

I have created a small OpenGL 3.3 (Core) program using freeglut. The whole geometry is two boxes and one plane with some textures. I can move around like in an FPS and that's it. The problem is I face ...
2
votes
0answers
408 views

GLSL Bokeh using Quads and Textures [closed]

I'm trying to create a depth of field effect with bokeh sprites in GLSL. Specifically, what i would like to do is, for each pixel: See if the pixel is out of the focal range If it is, draw a quad ...
11
votes
6answers
12k views

OpenGL ES 2.0: Repository of Quality Shaders

Could I kindly ask, to suggest me a repository of high quality OpenGL (OpenGL ES 2.0) vertex and fragment shaders, please? I am looking for pixel based ligting shaders (such as phong) and simmilar. ...
0
votes
1answer
313 views

What are the steps taken by this GLSL code?

1 void main(void) 2 { 3 vec2 pos = mod(gl_FragCoord.xy, vec2(50.0)) - vec2(25.0); 4 float dist_squared = dot(pos, pos); 5 6 gl_FragColor = (dist_squared < 400.0) 7 ? ...
0
votes
1answer
460 views

Correct Rotation and Translation with a 4x4 matrix

I am using a 4x4 matrix to transform verts in a shader. I multiply an identity matrix by a rotation matrix by a translation matrix. I am trying to first rotate the verts and then translate them, ...
6
votes
1answer
263 views

GLSL vertex shaders with movements vs vertex off the screen

If i have a vertex shader that manage some movements and variations about the position of some vertex in my OpenGL context, OpenGL is smart enough to just run this shader on only the vertex visible on ...
13
votes
1answer
2k views

Should I distribute shaders in a compiled form or in plain text?

Having an application that uses shaders that have been wrote in GLSL, what is the best strategy for the distribution in the real world and for the desktop and mobile? I'm aiming to distribute this in ...
6
votes
4answers
922 views

Impact of variable-length loops on GPU shaders

Its popular to render procedural content inside the GPU e.g. in the demoscene (drawing a single quad to fill the screen and letting the GPU compute the pixels). Ray marching is popular: This means ...
1
vote
3answers
1k views

iOS - pass UIImage to shader as texture

I am trying to pass UIImage to GLSL shader. The fragment shader is: varying highp vec2 textureCoordinate; uniform sampler2D inputImageTexture; uniform sampler2D inputImageTexture2; void main() { ...
5
votes
3answers
658 views

Finding out what pixel on the screen the fragment falls on

In my 2D game, I render tiles. I want to do lighting without needing an extra buffer the size of the screen. Either in glsl or hlsl, what could I feed to the shader each time I render a bitmap so ...
1
vote
0answers
255 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 ...
3
votes
1answer
2k views

Deferred Rendering and Normal Mapping

I'm working on a deferred renderer and need a bit of help getting normal maps working. What I've been doing with them so far is just multiplying the normal texture with the object normals ...
9
votes
4answers
4k views

Debugging Shader Code?

I'm writing a game engine, and when I use a perspective camera I get a black screen. I am not going to ask exactly why this is because there would be a lot of code to share and, frankly, I think ...
2
votes
1answer
2k views

Does Macbook Air 2012 (Intel HD4000) support GLSL 1.3+?

I'm using SDL2 and GLEW on OSX Mountain Lion (2012 Macbook Air) to create an OpenGL context. Querying for the GLSL version, it reports GLSL version 1.2. I'm curious if this is a limitation of the ...
3
votes
1answer
3k views

Sea water shader using only fragment processor

I have a game that runs on mobile devices (OpenGL ES 2.0) and for which I would like to create some sea water using the shaders. Now, the plane on which the sea water texture will be has only 4 ...
1
vote
3answers
590 views

Shaders not linking correctly

I'm writing a rather simple "ShaderManager" which aids me with loading shaders in Open GL, altough I am having a few issues: The shaders don't link correctly The the attributes don't bind Here's ...
1
vote
2answers
394 views

Lights system with shaders in OpenGL?

In more than just 1 occasion, i read about 2 ways of doing a light's system in OpenGL: normal way? i don't know how to call this one with the shaders ( GLSL ) The problem is i don't get the ...
1
vote
1answer
1k views

Shader authoring/editing tools for GLSL ES

Since Render Monkey has been discontinued (perhaps due to the complexity of today's shading languages), there are few successors that can match its functionality. Is there any useful tool for material ...
1
vote
3answers
595 views

Writing a shader once without using CG?

Is there a tool that can convert a fragment shader from hlsl to glsl or glsl to hlsl? I do not want to use cg since it is not able to work on mobile platforms. Is there a tool that can make it so I ...
2
votes
2answers
546 views

Lighting problems with Terrain

I'm in the process of learning Open GL and am having issues with lighting on my Terrian, I don't know if the issue is related to how I calculate my normals or the shader itself (I am using the shader ...
10
votes
1answer
529 views

Special relativity shader in GLSL

I'm trying to implement a GLSL shader which helps understanding special relativity Lorentz Transformation. Let's take two axis-aligned inertial observer O and O' . The observer O' is in motion w.r.t ...
8
votes
2answers
3k views

GLSL Shader Editors for Linux

Are there any good IDE's for linux that lets us edit GLSL shaders and visualize their effect? Note : Shader Designer By Typhoon Labs is a good option but I am looking for alternatives as this ...
1
vote
1answer
2k views

GLSL - rewriting (geometry) shader from #330 to #130 version

I'm having trouble running example from: https://raw.github.com/progschj/OpenGL-Examples/master/07geometry_shader_blending.cpp My graphics card supports only #130 shaders version so I have to rewrite ...
2
votes
0answers
270 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 ...
4
votes
4answers
413 views

Shader compile log depending on hardware

I'm done with the core of my graphics engine and I'm testing it on every platform I can get my hands on. Now, what I noticed is that different drivers return different shader and program compile log ...
0
votes
1answer
390 views

OpenGL Tessellation makes point

A little problem with my tessellation shader. I try to implement a simple tessellation shader but it only makes points. Here's my vertex shader : out vec4 ecPosition; out vec3 ecNormal; void ...
0
votes
1answer
674 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 ...
3
votes
1answer
3k views

GLSL if-else statement unexpected behaviour

This question is related to this other one I asked a few days ago. Because I have finally get to the bottom of the issue, I have rather preferred to open a new question with a more detailed ...
1
vote
1answer
184 views

Blur gets displaced compared to original image

I have implemented a SSAO and I'm using a blur step to smooth it out. The problem is that the blurred texture is slightly displaced compared to the original. I'm blurring using a 4x4 kernel since that ...
2
votes
2answers
2k views

Updating texture memory via shader?

What the title says.Is it possible to update a texture via a glsl shader ? Something like : //Read vec4 Pixel = texture2D(TextureID,gl_TexCoord[TextureIndex].st); //Write to texture memory ? vec4 ...
2
votes
1answer
487 views

Build-time GLSL syntax validation

Is there a way to validate GLSL syntax build-time instead of run-time? My application takes a long time to start and I want to know at the earliest possible stage that my shaders are ok. I'm using ...