A program that runs on the GPU to determine output colors for pixels. Also known as a fragment shader.

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Fragment Shader output type error

StackExchange! I've been working with opengl for a bit and I'm trying to finally load the shaders instead of having them inline. I'm having a ton of issues, though. As soon as I solve one, another ...
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103 views

How can I modify my procedural shadows to also show some of the walls?

I'm rendering shadows in Libgdx with the method from this tutorial. I think it's a nice and easy method. I render all my shadows in a framebuffer, then invert it. Before invert: After Invert: ...
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1answer
116 views

2D RGBA texture is gray in GLSL shader

I have a shader to perform LUT coloring of a texture and a c++/c# programs that call it which work perfectly when i use a 1D texture. Since i need to support computers that don't support the 1D ...
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2answers
2k views

cocos2dx - Custom Fragment Shader and CCRenderTexture

I have a CCRenderTexture that is filled with a sprite when the scene is loaded, as follows, canvas = CCRenderTexture::create(this->getContentSize().width, this->getContentSize().height); ...
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1answer
860 views

Two pass blur shader using libgdx tile map renderer

I am trying to apply the following technique: blur effect using two pass shader to my libgdx game using the OrthogonalTiledMapRenderer. The idea is to blur the background wich is also a tilemap but ...
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1answer
47 views

Is it possible to look up a texel from a texture in GLES2 GLSL framgent shader without using sampler?

Is there some way I can directly access texture memory from fragment shader in GLES2 GLSL? I don't need the sampler to be involved since I am just using it as a look-up table.
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1answer
120 views

Shadow mapping. I don't understand what to do after creating the depth texture

I'm taking an intro to computer graphics course, so this is something we haven't touched on. I am reading this tutorial ...
3
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2answers
801 views

Realtime fisheye to cubic or spherical panorama transformations with OpenGL or pixelshaders

I'd like to transform a sequence of circular fisheye-images to cubic or spherical panorama images to be used in a panorama-viewer based on OpenGL. The viewer-part is nemas problemas but the transform ...
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2answers
353 views

How to implement color changing fragment shader?

I have a background of a given size and filled with a given color. I want to change it with an animation effect, starting from the center and spread out until it extends the whole background. The new ...
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1answer
139 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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3answers
1k views

Why is H (blinn) used instead of R (phong) in specular shading?

I can't find a good reason for this anywhere. The reflection vector used in phong has a simple basis in physics. But the half vector used in blinn seemingly has no rational basis, and does not ...
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2answers
65 views

Best way to detect if vec3 is between vec3(x) and vec3(y) in glsl

As titled I am sampling from a texture and if the color is somehow gray [vec3(.8), vec3(.9)] and an uniform is 1 I need to substitute that color with another one I am not a glsl veteran but I am ...
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1answer
573 views

How do I achieve supersampling / anti-aliasing in pixel shaders?

I am trying to write a couple pixel shaders to apply to images similar to Photoshop effects. For example this effect: But I noticed there is aliasing in my resulting image (the above image is a ...
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2answers
194 views

Water silhouette shader using GLSL

I have this problem to solve using Cocos2d-x 3.x: In my game there is water represented by rectangle texture, modified by the code on the go. I also have a character moving around, rotating etc. I ...
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1answer
209 views

Can't sample texture in HLSL using DX11

Environment: Windows 7 x64 Visual Studo 2012 DirextX11 HLSL Shader Model 5 Ogre 1.9 Okay, so I'm trying to sample a texture in my pixel shader but I'm coming across some strange problems. Here's ...
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148 views

OpenGL shading doesn't work with different projection and view matrices?

I found an online (public-domain) code to do marching cubes, and I am trying to adapt this code to work in my own project. The code uses GLUT and "older-style" OpenGL, whereas I am using GLM and ...
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1answer
102 views

How to fix this existing shadow shader/material with alpha textures?

I hope I could get some help here in finally resolving this problem of mine re: shadow casting with alpha textures. Here's a screenshot on what I am hoping for as a result: A friend of mine just ...
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2answers
12k views

GLSL - one-pass gaussian blur

It is possible to implement fragment shader to do one-pass gaussian blur? I have found lot of implementation of two-pass blur (gaussian and box blur): ...
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2answers
229 views

Strange if-else branching behavior in a fragment shader

In my fragment shader I have passed an uniform int uLightType variable, which indicates what type of light is in usage right now. The problem is that if-else branching does not work correctly - the ...
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2answers
458 views

Fast fullscreen quad rendering in Direct3D 11?

For the last few weeks, I've been trying to port a DX9 implementation of HDR rendering (tone mapping, bloom, stars, etc.) over to DX11. I believe I've got all features working but I'm not getting good ...
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1answer
170 views

Manually writing a dx11 tessellation shader

I am looking for resources on what are the steps of manually implementing tessellation (I happen to be using Unity CG, but any help is appreciated). Today it seems that it is all the rage to hide ...
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2answers
111 views

Bad pixels on shader when loading cached binary programs

I have been trying to cache binary shader programs in my game and load them accordingly using "glGetProgramBinaryOES" and "glProgramBinaryOES" respectively. I was successfully able to cache and load ...
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1answer
119 views

Combine Two Shader Program [closed]

For my android application, I want to apply brightness and contrast shader on same image. At present I am using gpuimage plugin. In that I found two separate program for brightness and contrast as ...
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1answer
385 views

How to change pixel color of Texture with Fragment Shader

I want to change the pixel color of a texture. I don't know where to start and what to add. Really need help, I only find useless snippets in the internet. My current Code: public void ...
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1answer
366 views

Fog shader camera problem

I have some difficulties with my vertex-fragment fog shader in Unity. I have a good visual result but the problem is that the gradient is based on the camera's position, it moves as the camera moves. ...
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64 views

Pixel Shader : Backbuffer is 'Black'

After Fiddling around I am pretty sure this is not a Shader issue. Edit 4: The only diference I can see is that BasicEffect calls these methods before drawing: // Make sure that domain, hull and ...
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90 views

Very basic OpenGL ES 2 error

This is an incredibly simple shader, yet I'm having a lot of trouble understanding what's wrong with it. I'm trying to send a float to my fragment shader. Its purpose is to adjust the alpha of the ...
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1answer
52 views

Depth Map resolution shifting

the problem is with shadow mapping as you can see, actually it works fine but in a certain condition that the Depth Map size must be equal to the size of rendering buffer, I use an infinite ...
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1answer
234 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 : ...
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1answer
146 views

Normal Map Issues

I'm experiencing a very strange result in my very simple normal map implementation on iOS 7 - OpenGL ES 2.0. I'm only using the bare parameters necessary and I'm also skipping on all the tangent and ...
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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; ...
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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), ...
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1answer
1k views

2D Line drawing with Pixel Shaders

Recently I asked a question, what is the fastest way to render 2D lines using DirectX, and one of the answers mentioned this paper on Fast Prefiltered Lines which uses Pixel Shaders to accomplish ...
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2answers
464 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 ...
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2answers
264 views

gl_FrontFacing - is there perfomance cost?

If I use gl_FrontFacing in my PS, is there any performance cost during vertex transformation (like cross product from triangle vertices), or is this value computed any time ?
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1answer
78 views

blend skybox runtime

I use soil to load the cubemaps. the fragment shader uses cubeMap2 as the current cube map. However, I want to change the cube Map based upon an event. My problem is how can I change the cube map. ...
0
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1answer
337 views

Incorrect colour blending when using a pixel shader with XNA

I'm using XNA 4.0 to create a 2D game and while implementing a layer tinting pixel shader I noticed that when the texture's alpha value is anything between 1 or 0 the end result is different than ...
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1answer
199 views

DirectX11 pixel shader in pipeline is missing

I'm writing a program which displays a MS3D model using DirectX, and unfortunately, the result shows nothing on the screen. When I use the Graphics Debugger from Visual Studio 13, I notice that the ...
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1answer
320 views

GLSL blur shader algorithm results in a lumpy blur?

I'm writing a Gaussian blur shader and it's coming along pretty well. However, when I run it on a circle, the result is lumpy. I'm using a simple nested for loop to create the blur. Here's the code ...
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0answers
136 views

Best approach to depth streaming via existing codec [closed]

I'm working on a development system (and game) intended for games set mostly in static third-person views. We produce our scenery by CG and photographic techniques. Our background art is rendered ...
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1answer
2k views

Shader which supports vertex colors and pixel lights?

From my question at Unity Answers: Hello everyone, I'm facing a bit of a problem here: I need a shader which has the ability to colour individual vertices and be lit pixel by pixel. Until recently, I ...
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2answers
180 views

Is there a way to optimize this 2D lighting effect shader? [duplicate]

I'm doing a little 2D game in C++ with Direct3D 11. In the game I want to render a sort of shadow that covers part of the screen: To do this I am using this pixel shader: float4 PS_Main( PS_Input ...
0
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1answer
78 views

Why would I lose the D3D device during an HLSL unroll?

I have a pixel shader that downsamples a texture from one size to another. The downsample shader uses a nested 'for' loop to traverse the uv coordinates. When the for loop executes more than four ...
2
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1answer
149 views

Fragments never falling into spot light's cone

I am using GLSL version 1.20 with OpenGL 2.1 . I am trying to compute when a fragment falls into the area of a spot light. I have already set all the light values with glLightfv and glLightf, also ...
4
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1answer
228 views

Premultiplied Alpha And Alpha Testing

I have a shader that is supposed to work with either alpha blending or alpha testing, but the color values being passed in are premultiplied alpha values. Is there an easy/standard way to have it ...
0
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1answer
937 views

problem using glm::lookAt and glm::perspective

I'm trying to change the code from the 22th tutorial at http://ogldev.atspace.co.uk/, using the GLM library, but the result seems wrong. The problem is shown in the below picture: While it should be: ...
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2answers
397 views

Ward model implementation: specular component too weak

I'm trying to implement the Ward shading model, the anisotropic, computationally efficient version: This is how I made it: float alphaX=0.5, alphaY=0.5; // asinotropic roughness float ...
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0answers
99 views

Can't understand the Schlick model formula

I'm trying to implement the Schlick shading model in the fragment shader. I took the formulas from Karsten Schwenk's "a survey of shading models for real-time rendering": First of all I don't ...
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0answers
31 views

Strauss model : no specular component [duplicate]

I implemented the Strauss model with the metalness, transparency and smoothness parameters, taking the formulas from the book "Programming vertex geometry and pixel shaders", this is how I implemented ...
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0answers
167 views

How can I compute spotlight attenuation when I only have a spotlight cutoff angle?

I am trying to compute the spot light attenuation, though I don't have a spotCosCutoff (cosine of the spotlight cutoff angle) predefined variable in the shader so I have to compute it myself. This is ...