A programming language for OpenGL shaders.

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104 views

Why does my vertex shader produce no output until I add some arbitrary value to the position attribute?

I want to draw a textured quad but there is nothing drawn and the setup should be right. This is my vertex shader: #version 330 in vec2 position; in vec2 texel; out vec2 texCoord; void main() { ...
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1answer
199 views

3D position of an arbitrary UV coordinate

I have a UV map for a 3D mesh that encodes "links" between pairs of UV coordinates. I have previously defined this links (or pairs), one to one. The links are enconded using the function rgb_color(u1, ...
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1answer
98 views

Blurring part of the screen - optimisation

I develop 3d menu and sometimes I need to blur only part of the screen. I use a forward rendering. I create a frame buffer object with 3 color attachments. Rendering looks like this: bind fbo ...
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1answer
78 views

Proper way to encapsulate a Shader into different modules

I am planning to build a Shader system which can be accessed through different components/modules in C++. Each component has its own functionality like transform-relevated stuff (handle the MVP ...
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1answer
155 views

GLSL to Cg fragment shader

I have found very useful resource on the Swiftless website on OpenGL. Unfortunately, I cannot manage to adapt a GLSL fragment shader to my project, which uses Cg. Here it is: uniform sampler2D ...
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1answer
336 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
306 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
135 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
179 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
359 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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2answers
448 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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1answer
241 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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1answer
390 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: Image1 in this image is a plane ...
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1answer
257 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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1answer
231 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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1answer
338 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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1answer
238 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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1answer
393 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
846 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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1answer
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
867 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
698 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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27 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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32 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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24 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
41 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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0answers
25 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
27 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
37 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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0answers
52 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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52 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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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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71 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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0answers
26 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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1answer
40 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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0answers
47 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
64 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 ...
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1answer
96 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(); ...
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1answer
89 views

Grayscale and 2D lighting using cocos-2dx

I want to create a lighting effect on a gray-scaled world using cocos2d-x. What I've done is creating a layer which runs a shader program that receives light positions and radiuses as input and ...
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0answers
76 views

Artifacts rendering high-poly procedural meshes with OpenGL

I am having some issues when rendering some procedural generated meshes. There are some really wierd artifacts when rendering high-poly count meshes (not that much actualy). I have been able to ...
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0answers
53 views

Dynamic VBO update possibly corrupting data?

I want to draw a line between two vertices. On a mouseclick the vertex data will change and I want to update the line to use the new values. I am using a VBO for this and it looks like the update ...
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0answers
71 views

Tessellation shader pass-through : Nothing displayed

I am trying to set a pass-through tessellation shader and then build on top of that while learning. From what I found/read I need to do in the TE shader everything that was done in the vertex shader ...
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0answers
22 views

Artefact in VSM as if GL_DEPTH_TEST disabled

I am trying to implement VSM and I incurred in a strange issue. I render them as follow: glUseProgram(shadowMapProgramID); glEnableVertexAttribArray(0); glBindFramebuffer(GL_FRAMEBUFFER, ...
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0answers
20 views

Transform screenquad around object's view space boundaries (GLSL)

Im not sure how to ask this, but essentially I am looking for a way to optimize rendering screen quad lights per object. I have a deferred renderer that draws directional lights onto a screen quad. ...
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1answer
101 views

How to load and render PhysX 3.3 heightfield

I'm trying to load a PhysX 3.3 heightmap and render it with OpenGL using glm and glfw, but so far it doesn't seem to be working. I'm basing my code on the PhysX samples, and am also using FreeImage to ...
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143 views

Problems texturing a sphere using a cubemap

I have a single problem which I've attempted two methods to resolve. Neither is giving me 100% results. I've read about 100 tutorials and looked at code but it's just not working out for me; I believe ...
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0answers
77 views

Is it possible to loop over an array of samplerCube/samplerCubeShadow using OpenGL/GLSL?

I try to manage a scene with several point lights. For the moment my program works perfectly with just one point light. So I have in my fragment shader the following uniform declaration: uniform ...
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0answers
21 views

Shader | Special Effect - Unit selection [duplicate]

I would like to know how the shaders used to show which unit is selected are made. Here is an image to illustrate. How the merge effect of the blue circles can be achieved ? I didn't found any ...
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0answers
44 views

GLSL 150 (or upper) per pixel lighting base code

I'm looking for a working example of smooth per pixel shading for one directional light I've seen this example http://www.opengl.org/sdk/docs/tutorials/ClockworkCoders/lighting.php but its old GLSL ...
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2answers
168 views

Passing variables down the pipeline glsl

I am sorry to post a question that may be easily tested, but I don't have an OGL4+ hardware at the moment and I have to make some design decision beforehand so I wanted a clear scenario. Looking at ...