A programming language for OpenGL shaders.

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9
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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
509 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
385 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
570 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
539 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
508 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 ...
0
votes
0answers
303 views

Making shaders work for both ATI and NVIDIA in Blender Game Engine [on hold]

Unfortunately coding OpenGL shaders is more strict for ATI cards. I am trying to get this code from this thread http://blenderartists.org/forum/showthread.php?245954-preethams-sky-impementation-HDR to ...
2
votes
0answers
257 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
379 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
377 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
654 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
183 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
464 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 ...
7
votes
1answer
1k views

Not getting desired results with SSAO implementation

After having implemented deferred rendering, I tried my luck with a SSAO implementation using this Tutorial. Unfortunately, I'm not getting anything that looks like SSAO, you can see my result below. ...
4
votes
1answer
586 views

My GLSL shader isn't compiling even though it should. What should I investigate?

I'm porting an iOS game to Android. One of the shaders I'm using wouldn't compile until I reduced the number of uniform variables. Here are the uniform definitions: uniform highp mat4 ...
2
votes
1answer
2k views

How to detect GLSL warnings?

After compiling a shader with glCompileShader, I can call glGetShaderiv with GL_COMPILE_STATUS to check if the shader compiled successfully. I can also call glGetShaderInfoLog to get information about ...
0
votes
1answer
957 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 ...
2
votes
1answer
1k views

GLSL compile error when accessing an array with compile-time constant index

I have this shader that works well on my computer (using an ATI HD 5700). I have a loop iterating between two constant values, which is, afaik, acceptable in a glsl shader. I write stuff in two arrays ...
11
votes
1answer
7k views

in/out keywords in GLSL

I don't really understand how to use the in / out keywords in GLSL, and google is being uncharacteristically unhelpful. What exactly do they do? How would I use them if, for example, I want to pass a ...
6
votes
1answer
2k views

How to invert background pixel's color

I'm writing a game and map editor using Java and jMonkeyEngine. In the map editor, I've got a brush done by wireframed sphere. My problem is: I want to make it visible everywhere, so I want to invert ...
1
vote
3answers
630 views

GLSL mesh discard command?

Is there a GLSL command similar to the discard, but it discards the whole mesh and not just a fragment?
0
votes
2answers
786 views

Can't render to FBO using a shader

I've added functionality so that I can render to a framebuffer (for post-processing and stuff). I can successfully render to my framebuffer and then render that framebuffer, but anything with a ...
1
vote
1answer
333 views

How to calculate the viewing cone radius at a distance in raymarching?

I'm "raymarching distance fields" (proper lingo: sphere-tracing) in GLSL. To implement cone-marching atop of it (and also to minimize the number of raymarching steps regardless of whether ...
0
votes
2answers
765 views

GLSL shader compilation

When i'm compiling a shader does it have to be complete? Can i use glCompileShader on a shader without a main() function? The OpenGL reference documentation has a nice writeup on program linking ...
1
vote
1answer
279 views

Steps to take before trying to implement screen space ambient occlusion

I very recently started learning modern OpenGL. I have implemented a wavefront file loader and a basic ADS shading model. At some point I'd like to implement screen space ambient occlusion. I tried ...
0
votes
1answer
754 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 ...
0
votes
4answers
1k views

Render 3D torus shape entirely in GLSL

I was wondering, is it possible to render a (3D) torus shape entirely in GLSL, i.e. without using vertex/index arrays? Suggestions are welcome, thanks.
5
votes
1answer
416 views

Raymarching artifacts

I was playing with raymarching using distance fields in GLSL sandbox and got stuck with a strange problem with artifacts. Click here and take a look at the spheres generated in corners, they have ...
2
votes
1answer
1k views

GLSL Shader Solution for Ambient Occlusion?

For the iOS app I am writing I want to incorporate some aspects of ambient occlusion for photo manipulation. Can someone suggest a GLSL approach that will work. Realtime performance is not super ...
2
votes
0answers
2k views

How to implement fisheye effect with a GLSL fragment shader [duplicate]

I would like to render my scene with a wide FOV and then apply a fisheye distortion via fragment shader. How would this shader best be implemented? Update I try to reproduce a fisheye effect similar ...
2
votes
2answers
922 views

Optimizing gaussian blur with linear filtering

There's a few (here, and here) gaussian blur tutorials out there suggesting that you can essentially cut the number of texture lookups in a gaussian blur shader in half by exploiting the GPU's ...
5
votes
3answers
4k views

how to add water effect to an image

This is what I am trying to achieve: A given image would occupy say 3/4th height of the screen. The remaining 1/4th area would be a reflection of it with some waves (water effect) on it. I'm not sure ...
2
votes
3answers
1k views

Passing POD arrays to shader?

How do I pass to my vertex shader an array of N elements? From what I see I can only pass float arrays of 3|4 elements, vectors 2|3d and matrices, but I want to pass a POD array and use it like this: ...
8
votes
2answers
482 views

Sharing functions across multiple shaders

Simple question: In GLSL, is there a way to share functions across multiple shaders, or do I have to define all functions in every shader that needs them?
6
votes
1answer
565 views

GLSL subroutine not being used

I'm using a gaussian blur fragment shader. In it, I thought it would be concise to include 2 subroutines: one for selecting the horizontal texture coordinate offsets, and another for the vertical ...
1
vote
2answers
903 views

How to achieve this particular screen filter with GLSL?

I know this may be a "short" question, but still here it goes. I would like to know how to achieve a post rendering effect, that looks like the following image from walking dead series: I will ...
37
votes
2answers
3k views

How to render realistic ice?

I am trying to write an ice shader in Unity that looks good and at least semi-realistic. If the following shot (found on Google) was CG, what would its shader include? (the foreground cave). I might ...
4
votes
1answer
2k views

Proper way to do texture mapping in modern OpenGL?

I'm trying to do texture mapping using OpenGL 3.3 and GLSL 150. The problem is the texture shows but has this weird flicker I can show a video here. My texcords are in a vertex array. I have my ...
1
vote
0answers
356 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 ...
1
vote
1answer
1k views

Why doesn't my texture display with this GLSL shader?

I am trying to display a DXT1 compressed texture on a quad using a VBO and shaders, but I have been unable to get it working. All I get is a black square. I know my texture is uploaded properly ...
3
votes
4answers
5k views

How do multipass shaders work in OpenGL?

In Direct3D, multipass shaders are simple to use because you can literally define passes within a program. In OpenGL, it seems a bit more complex because it is possible to give a shader program as ...
2
votes
1answer
323 views

Update single entry in GLSL array

I have an array in my vertex shader like this: uniform mat4 MeshTransforms[20]; At the moment I'm just updating the entire array of matrices like so: int meshTransforms = ...
4
votes
1answer
584 views

Can I use the default depth buffer when drawing to FBO?

How to attach default depth buffer to FBO? How to use depth renderbuffer buffer attached to FBO (after drawing to it) as a default depth buffer? Basically I want to use the same depth buffer for both ...