A programming language for OpenGL shaders.

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3
votes
2answers
192 views

Shader - Calculate depth relative to Object

I am trying to calculate depth relative to the object.Here is a good solution to retrieve depth relative to camera : Depth as distance to camera plane in GLSL varying float distToCamera; void main() ...
1
vote
1answer
1k views

What is the relationship between glVertexAttribPointer index and GLSL location?

I've been getting some strange results when trying to implement a normals buffer for the purpose of rendering lighting. It seems to be related to the indexes for glEnableVertexAttribArray, ...
3
votes
1answer
187 views

How to share values between different shader programs?

I am using Unity but this might concerns all type of shaders. I would like to know if this is possible to share values between different shader pass.Let's imagine that I am computing something in the ...
0
votes
3answers
82 views

Arbitrary number of VBO to Vertex Shader

I am currently using standard modern OpenGL way to render a mesh via VBO and attributes glEnableVertexAttribArray(aVertexPosition); glBindBuffer(GL_ARRAY_BUFFER, VBO); ...
1
vote
1answer
263 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() { ...
0
votes
0answers
181 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 ...
2
votes
1answer
215 views

OpenTK GL.DrawElements is never called

I found this C++ code here. It draws simple rectangle. Works great. #define GLEW_STATIC #include <iostream> #include <glew.h> #include <freeglut.h> const GLchar* vertexSource = ...
0
votes
0answers
135 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 ...
0
votes
1answer
280 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, ...
6
votes
1answer
2k views

Exponential Variance Shadow Mapping - implementation

I use a variance shadow mapping with a "standard" light bleeding fix in my graphics engine which is based on deferred rendering.. I have a single shadow map for a directional light beacause a test ...
2
votes
1answer
61 views

How to know when graphics driver or card changes

I'm about to start work on implementing GLSL binary shader compilation and I was curious how to handle the cases when the shaders need to be recompiled, such as when the driver (or perhaps even the ...
0
votes
1answer
117 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 ...
1
vote
1answer
48 views

Only affect pixels in buffer with alpha 0

I'm working on a transition effect where I have a texture and simply draw that as a pattern to my buffer. Here is a demo, use "e" to start the effect again. This looks fine but it won't work if the ...
1
vote
0answers
362 views

Is it reasonable to use a 2D texture as a lookup table in GLSL

I need a lookup table in a shader. The input values would be color values and the output other color values. Something like: uniform float lut[256]; color = vec3(lut[int(color.r*255.)], ...
0
votes
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 ...
1
vote
1answer
195 views

Vertex shader in OpenGL/GLSL - transformation of the interior of a textured quad

I have a LWJGL project and ran into a problem with a vertex shader I wrote. In my scene I am rendering a map whose ground consists of rectangular tiles. On top of that there are other objects (I used ...
0
votes
1answer
98 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 ...
0
votes
2answers
101 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 ...
0
votes
0answers
56 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 ...
5
votes
1answer
668 views

How can glass breaking effect from Smash Hit be achieved? [duplicate]

I saw Smash Hit the other day and was amazed by the physics of the game, specially the shattered glass effect: I've read other posts about this subject but I still feel that they don't share enough ...
2
votes
2answers
304 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 ...
1
vote
1answer
120 views

Unity, shader, vertexID

I'm writing a shader and I just wanna ask if it's possible to get the ID of the vertex that is currently being manipulated. I read something about gl_vertexID, but I couldn't find out if that is ...
18
votes
1answer
8k views

How do Raymarch shaders work?

I have been looking at shaders found here shadertoy.com and most of the cool ones have noise and raymarch in common. I do not understand the source code at all but I really want to. How do these ...
1
vote
2answers
214 views

GLSL to Cg: why is the effect different?

With reference to this question, where I was trying to make the shader compile, I am now trying to make an effect appear. The effect can be shown here, through a GLSL shader: But when I use the ...
1
vote
0answers
361 views

implementing shadows into my 2D GLSL-based lighting system

I'm writing a lighting system in OPENGL using GLSL shaders, and I'm pretty happy with the light casting I have so far, but I'm totally stuck on casting shadows. Everything I've found online on this ...
1
vote
1answer
149 views

GLSL Processed Image to OpenGL

I've tried wording and rewording this question in various forms of search and can't seem to find an answer to it. If I'm wording it wrong and/or just not finding the right information, feel free to ...
4
votes
2answers
1k views

Per-pixel displacement mapping GLSL

Im trying to implement a per-pixel displacement shader in GLSL. I read through several papers and "tutorials" I found and ended up with trying to implement the approach NVIDIA used in their Cascade ...
3
votes
2answers
344 views

Render with multiple lights (one pass per light)

I have already a system that at the moment handle multiple lights just passing an array of light struct and loop through it. I had been told to switch to a multipass rendering approach. How should I ...
19
votes
1answer
3k views

Why does this geometry shader slow down my program so much?

I have an OpenGL program, and I'm rendering a terrain mesh. I displace the vertices in the vertex buffer and don't really color them in the fragment shader yet. I'm adding a geometry shader one part ...
10
votes
2answers
15k 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): ...
0
votes
2answers
284 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 ...
2
votes
2answers
428 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 ...
0
votes
1answer
224 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 ...
0
votes
0answers
173 views

Problem when using two different shaders

I have created a simple shader for drawing my scene in OpenGL. When another shader was introduced, a problem appeared. I use the first shader and draw few objects in the scene. Then I use the second ...
3
votes
1answer
241 views

what happens with missing vertices in geometry shader

I am relatively new to GLSL shader programming, and the documentation I found is unfortunately often inscrutable. I am having trouble understanding a few things with how geometry shaders fit into the ...
0
votes
1answer
285 views

What coordinates are we passing to pixel shader from vertex shader?

I have read articles about shader programing and understood the very basic knowledge of shader programing. One thing I always get confused is about the texture mapping. What I pass(output) from VS to ...
1
vote
0answers
261 views

How to shade hair (line segments) correctly in GLSL

I render my hair geometry in line segments. The problem I have is with the correct shading of the hair. From what I've read I understood that I need the direction of the line segment and the ...
0
votes
1answer
379 views

More than 8 lights without deferred shading / lighting [closed]

I want to know if there is any technique (efficient) to use more than 8 lights in a scene made ​​with OpenGL and GLSL. Without making use of deferred shading / lighting. I have not implementadon ...
1
vote
2answers
144 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 ...
3
votes
2answers
2k views

2D Outline shader in GLSL

I have a simple prototype with 2D worms-like destructible terrain. I use a trivial shader to discard pixels based on a mask. varying vec2 v_texCoords; uniform sampler2D u_texture; uniform sampler2D ...
3
votes
1answer
366 views

Handling multiple lights of different types in GLSL

I want to be able to support multiple lights of different types (point, spot & directional). Note that I also want to be able to render transparent/translucent objects, which rules out deferred ...
2
votes
3answers
2k views

GLSL Sphere from Vertex

I am working on a particle simulation where we have a lot of spheres which can have different radii. Using this tutorial http://mmmovania.blogspot.de/2011/01/point-sprites-as-spheres-in-opengl33.html ...
1
vote
1answer
218 views

Blinn, Normal maps & Fresnel?

So something came up today when I was going over my Blinn shader. As I've been taught, the half-angle vector is calculated in the fragment shader, and is equal to normalize(lightDir + viewDir). This ...
1
vote
1answer
226 views

Normal Mapping space confusion

I've been reading today about normal mapping. Up to now, the only normal mapping I encountered was with maps already in world space so I just extracted the info from the texture and transformed them ...
9
votes
1answer
410 views

How can I reliably implement GPU skinning in Android?

I'm trying to get character skinning working on Android. The idea is quite vanilla: I have my skinning matrices, and along with each vertex, I send up to four matrix indices and four corresponding ...
1
vote
1answer
125 views

Component-wise GLSL vector branching

I'm aware that it usually is a BAD idea to operate separately on GLSL vec's components separately. For example: //use instrinsic functions, they do the calculation on 4 components at a time. float ...
-1
votes
2answers
81 views

GLSL Normals not transforming propertly

I've been stuck on this problem for two days. I've read many articles about transforming normals, but I'm just totaly stuck. I understand choping off W component for "turning off" translation, and ...
1
vote
0answers
67 views

Normal map lighting bug in bottom right quadrant [closed]

I am currently working on getting normal maps working in my project, and have run into a problem with lighting. As you can see, the normals in the bottom right quadrant of the lighting isn't ...
2
votes
1answer
72 views

Why do the order of uniforms gets changed by the compiler?

I have the following shader, everything works fine when setting the value of one of the matrices but I've discovered that getting a value back is incorrect for View and Projection, they are in reverse ...
2
votes
2answers
646 views

Colorize with a given color a texture

I have a texture and I want to "colorize" it with a given color, lets say cyan (#00ffff) or purple (#800080). What I want to do, is get all the pixel values from the texture, and remove the color and ...