A programming language for OpenGL shaders.

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195 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 ...
0
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1answer
238 views

Optimizations using GLSL shaders

I have written a simple OpenGL application using GLSL shaders. Actually, my program just displays a simple cube with a phong lighting effect like below : Here's a peace of the client code : ...
2
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1answer
244 views

How does GL_INT_2_10_10_10_REV work for color data?

Can anybody tell me how exactly to use GL_INT_2_10_10_10_REV as type parameter in glVertexAttribPointer()? I am trying to pass color values using this type. What is the significance of "REV" suffix ...
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1answer
159 views

GPU skinning algorithm incorrectly distorts mesh

I've been trying to implement a GPU-based matrix palette skinning algorithm with WebGL, but the rendering appears incorrect even though I can't find evident conceptual problems in the underlying ...
5
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1answer
190 views

How can I implement real-time mutual object reflection?

So, given a scene like this (cubemap skybox with "real" spheres) Everything looks great, except for the fact that the spheres don't reflect each other. What's a good way to go about this? The ...
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1answer
148 views

Gamma Space and Linear Space with Shader

I am using Unity and I can choose between two color space mode in the settings: Gamma or Linear Space. I am trying to build a Custom Lighting Surface shader but I am facing some problems with those ...
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1answer
410 views

gl_VertexID values when calling glDrawElements

I am struggling a bit to understand the values that gl_VertexID primitive contains when the vertex shader is executed. I have the standard modern rendering pipeline, in which after setting up ...
-1
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1answer
122 views

Unity's pack 4 floats

Linked to: GLSL pack floats into an RGBA texture I found EncodeFloatRGBA/DecodeFloatRGBA shader functions in Unity https://gist.github.com/hecomi/9580605 Now I try to figure out how they work. So I ...
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1answer
101 views

How can I animate a portion of the textures on a model?

I have a model to which I have attached multiple textures. Both textures are currently static, but if I want to move (or slide) the texture which is on the top (in UV space), is that possible? Maybe ...
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2answers
792 views

GLSL: can i use matrix transformation functions in vertex shader?

I have a working OpenGL code where i render a terrain with some trees. I am doing all the matrix mathematics on the client side. Because of which the frame rate of my app is very low, around 25-30 ...
0
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1answer
96 views

Providing texture coordinates and using indexed drawing at the same time

Please consider the following vertex structure struct vertex { vec3 posL, normalL; }; Using this vertex layout, we can provide the vertex data in an interleaved way, i.e. ...
2
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1answer
257 views

How can I repeat / scroll a tile which is part of an texture atlas?

I would like to scroll a tile which is part of a texture atlas like it can be done with a single quad and texture wrap mode set to repeat. Can this be done? I hope it's clear what I would like to ...
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1answer
91 views

Why aren't subsequent glDrawArrays showing up?

I am attempting to redraw with the same arrays using glDrawArrays in a GLKView on iOS. When I comment out any two of these calls, the other draw call draws as I expect. My last hunch was that I was ...
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0answers
95 views

Using multiple uniform blocks in OpenGL

I'm using OpenGL with JOGL and want to use two unfirorm blocks in my vertex and pixel shaders. The following GLSL-Code shows the definitions:- uniform perObject { Material uMaterial; mat4 ...
5
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1answer
2k views

GLSL pack floats into an RGBA texture

I want to compose conventional triangle-based models and particles with a ray-traced scene at a reasonable frame-rate. webGL does not let you write the gl_FragDepth in the fragment shader. You ...
2
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1answer
424 views

Alpha Blending: use the pixel with the smallest alpha

I'm writing a transparency shader where I need any intersecting textures to, wherever they overlap, take the texture pixel with the smallest alpha value and render only that, discarding the other ...
2
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2answers
252 views

Does GLSL copy function arguments by value?

My question is about passing variables to GLSL shader. I'm not sure how that works and what are the performance implications. Say I got a function that accepts a "vec4" variable. The question is - is ...
2
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1answer
91 views

How to store an array into a texture and sampler the texture in vertex shader correctly?

I'm a new learner about OpenGL and GLSL. I'm coding a program in which i wanna store a group of datas in a texture and get the data by sampling the texture in vertex shader. Then i want to set the ...
2
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0answers
1k views

2D water shader in SFML

I want to implement the algorithm for a 2D water surface described here and here. Before somebody finds out, beats me up and deletes this, I'm gonna say it myself. I posted this question over at ...
4
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1answer
909 views

Shadow mapping does not work correctly using GLSL shaders

I'm a beginner in shadow mapping. I have in my scene two meshes : a cube and a floor. The scene is lighted by a single point light. Here's for the following display the light properties : ...
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2answers
4k views

FBO Depth Buffer not working

I'm trying to get the depth buffer for my 2D game working by offsetting the z value of the rectangles. For some reason, my depth buffer is coming back empty. The value is always 0. I'm assuiming there ...
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1answer
45 views

Having trouble setting color in fragment shader

For some reason, the color isn't applying to the object. Here's my fragment shader code. There's probably something obvious wrong with it that i'm not seeing. #version 330 core out vec3 Color; ...
0
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1answer
105 views

How does OpenGL determine different outputs with shaders?

Lets say I have this GLSL code: #version 330 out vec4 outputColor; void main() { float lerpValue = gl_FragCoord.y / 500.0f; outputColor = mix(vec4(1.0f, 1.0f, 1.0f, 1.0f), ...
3
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1answer
132 views

Applying a noise texture to distort edges

I asked this question over on StackOverflow but then found this site, and it's probably better suited to here. I'm trying to implement Sketchy Drawings. I'm at the part of the process which calls ...
1
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1answer
235 views

Why is the light following my camera around?

I have implemented a simple Phong shader without specular highlights for now (just ambient + diffuse components) The problem however, is that the calculations seem to be done in camera space; as I ...
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1answer
71 views

How do I follow this glsl1.2 + lights + shadows tutorial?

I am following this great tutorial but I have many questions. Let's see if I understand the basic idea. 1. I must create the same number of FBOs that lights (maximum 8). 2. I must create the same ...
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2answers
170 views

GLSL: sampler2D fallback to constant color?

So I have the following situation: I'm sharing a blinn shader accross many meshes. Some meshes have specular & normal maps, others do not. I'd like to, without making the shader code too ...
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2answers
465 views

3D position to UV coordinates in fragment shader

I am interested in converting an arbitrary 3D position computed at run time in the fragment shader to its corresponding UV coordinates. Notice that the 3D position I am interested in is NOT a 3D ...
0
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1answer
255 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
105 views

In glsl, how do indices work?

I have made a vertex shader and fragment shader and kind of know how they work, and I know that you specify what index you want your vertices to be in inside the shader program. So if the vertex was ...
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2answers
1k views

Refractive glass shader

I have an infinite hexagonal floor, generated by tessellating a point grid in a tessellation shader pair: Note that this is a flat wireframe - the "shadows" are a lighting trick: Now, I'd like ...
1
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1answer
429 views

GLSL - std140 uniform block - fields(vec, float, mat4) always 0.0

Ok, First of all, if just use uniforms everthing works like it should. Switching to uniform blocks nothing goes, as all values look like 0.0. I tested this with various if-then-else stuff within the ...
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0answers
158 views

glsl fragment shader work diffrently on different devices

i'm making a 2d android game where i have a mechanics that allow the player to move the camera away from the main character, and to not allow him to explore the hole world, a have create a Fog shader, ...
5
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1answer
2k views

GLSL Light (Attenuation, Color and intensity) formula

I'm implementing point lights in my Voxel engine, and I'm really struggling to get a good flow of light, from 100% near the light source to 0% at the light radius. I have 5 arguments for the ...
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1answer
137 views

GLSL associating multiple uniform samplerBuffers

At the moment I'm not sure how my VBO and TBO associate with a specific uniform samplerBuffer in my shader, I have not linked them using the location or the vbo/tbo together. It seems to still work ...
2
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0answers
538 views

Normal mapping does not work correctly using GLSL and OpenGL [closed]

Hello I wrote a simple OpenGl program using GLSL to render a simple uv mapped plane using the normal mapping technics. Here's the display with a simple phong shading (without normal mapping) : Now ...
0
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1answer
105 views

GLSL/SFML - Only make portion of texture alpha

I'm trying to take a portion of the current texture and turn it to 50% transparent. I send in four values, signifying the rectangle I want to make transparent. It seems every time, however, that ...
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2answers
205 views

How to mix pixel colors in Shader?

I have a pixel that have a colour RGB. This color is calculated by the shader and can be anything. How can I override this color by a colour I choose. If my pixel is white it's simple, I can do this: ...
1
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1answer
619 views

View to normal calculation in GLSL

Sorry for the terrible title, but I really cant think of anything better.. Suggestions welcome. I am trying to do something like showcased in this video: http://www.youtube.com/watch?v=CaTI2d0tQME ...
6
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1answer
413 views

Weird problem with advect program in fluid simulator

I implemented 2d fluid simulator. Solver runs entirely on GPU. All works fine... on my work PC. But on home PC I have some awful glitches, and I can`t understand how to fix them. Empirically I ...
5
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1answer
1k views

What is the recommended way to output values to FBO targets? (OpenGL 3.3 + GLSL 330)

I'll begin by apologizing for any dumb assumptions you might find in the code below since I'm still pretty much green when it comes to OpenGL programming. I'm currently trying to implement deferred ...
2
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1answer
175 views

How to work with smaller intermediate textures in OpenGL and GLSL?

I'm working on a project rendering water simulated through smoothed-particle hydrodynamics (SPH) with a non-photorealistic look to use in games. In the actual stage of the project everything about ...
1
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1answer
529 views

SSAO looks wrong

I'm trying to implement SSAO based on this tutorial. My setup: OpenGL 3.2 Forward renderer View-space depth and normal in a single 16-bit floating point texture. The result I get is this: The ...
16
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2answers
8k views

Is there a successor to RenderMonkey? [closed]

I'm starting with GLSL shader programming and have been looking into RenderMonkey. Sadly, AMD no longer supports it. Why? Is there a successor to it?
0
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1answer
116 views

why is my OpenGL texture transparent?

I have a terrain in OpenGL, and two textures which I am combining using GLSL mix() function. Here are the textures I am using. Now I am able to combine and mix these two textures, but for some ...
0
votes
1answer
114 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. ...
1
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1answer
669 views

How to achieve anisotropic filtering

I am loading a texture and using glGenerateMipmap() on it to achieve some level of mipmaping. I get different result on nVidia gt 555m, and on Intel HD 3000. The texture rendered by nVidia is not ...
9
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3answers
867 views

How can I create a glitter effect?

I am trying to create a glittering effect for my realtime shader but I don't know how. Here is one example, and another example. What technique can I use to implement this?
2
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1answer
269 views

Linear filter problem with diagonal lines on adjecent tiles

I am quite new at using OpenGL/GLSL. Basically, the project I am working on is my first 'real' experience with it. I do not know whether this is relevant, but I use libgdx for my project. Currently, ...
4
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1answer
635 views

Why are my texture coordinates always (0,0) in this shader?

What I'm trying to do is add my depth buffers values to my scene, ie. I'm trying to make objects closer to the camera darker and objects further away lighter. Which should be easy: just render the ...