A programming language for OpenGL shaders.

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2answers
187 views

How to wrap textures inside shader GLSL

I'm trying out GLSL and one of the problems I'm facing is wrapping a random texture sampler in the shader. Searching for answers on the web first, this leads me to using these commands: ...
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1answer
120 views

Can glsl main() have params or return a value?

I haven't ever seen anyone declare main as anything but void main() or void main(void) but I'm curious, is it possible to have a parameter or return value?
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1answer
125 views

Shader - Color blending

I would like to know how to blend colors in a specific way. Let's imagine that I have a color (A) and an other color (B). I would like to blend them in such a way that if I choose white for the (B) ...
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1answer
82 views

Reconstruct shader vertices in OpenGL

I'm not sure if 'reconstruct' is the correct term for this but essentially what I am trying to do is calculate vertex positions (that are already calculated via shader) on the CPU for the purpose of ...
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2answers
353 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: ...
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1answer
43 views

OpenGL is box blur this slow?

I've never tried blur until recently, and by that i've noticed fps drop when doing box blur. My fps will go down from 4000-5000 fps to 1000-1500 fps. Currently rendering at 853x480 frame buffer and ...
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1answer
75 views

Projection Matrix Breaks My Rectangle

This is my vertex shader, shown below. #version 330 core in vec3 a_position; in vec4 a_colour; // FOV = 70, near plane = 0.1, far plane = 1000 const mat4 u_projection = mat4( 1.428148, 0.0, ...
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2answers
126 views

Why does rotating my quad appear to move it farther away?

I have created a 3x3 matrix class which is then passed over to OpenGL Vertex Shader for transform my Quad. I have been trying to rotate my Quad around Z-Axis. Rotation is working but the Quad getting ...
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2answers
73 views

Shader value remap - Blend Falloff

I would like to know if there's a way to remap a value that goes from 0 to 1 constantly like this. Into those values (those are examples). This might be some function transformation but I can't ...
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3answers
87 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); ...
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1answer
365 views

is instanced rendering faster? [closed]

Is instanced rendering used in GLSL faster than doing something like this.. for(int i=0; i<10; i++) { glDrawArrays(GL_POINTS, 0, 3000); } Suppose I want to render 'grass', which is the best ...
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1answer
117 views

How can I avoid applying textures to a fragment in a shader when the surface normal is (0, 1, 0)?

I have a small GLSL shader with a vertex shader and a fragment shader. I want to avoid applying textures to faces that have a normal equal to (0, 1, 0). Is this possible? These are my shaders: ...
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1answer
367 views

VBO in a class doesn't draw when The class has a destructor

I am making this class QuadTemplate class QuadTemplate { public: QuadTemplate() { vbo=0; uvbuffer=0; vao=0; TextureID=0; vboType=0; ...
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1answer
155 views

deferred rendering and a few shading functions

How to use a few shading functions together with deferred rendering (for example some objects are shaded based on a lighting equation, other get a fixed color) ? I draw a full screen quad when ...
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3answers
1k 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 ...
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1answer
18 views

GLSL uniform array with size set by another uniform

Will the follwing GLSL code work? #version 330 uniform int size; uniform float[size]; void main() { //do something }
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2answers
57 views

How to optimize this branching instruction?

I have an outline shader, which samples my texture 8 times to compute the outline. The problem is, that there's transitional alpha values between picture and background. To cut them off I'm using the ...
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1answer
353 views

Terrain shader from heightmap opengl GLSL

I generated a terrain from a heightmap and now I'd like to apply shader on it which can contain different textures, based on height but I can't adapt any online code to my project. This is the ...
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1answer
243 views

Java, Crashing with a Shader on Intel HD Graphics

I just got a new computer (Acer Aspire ES1-311) which has an integrated Intel HD Graphics card, and I noticed that this fisheye shader crashes my game (LibGDX game, VM Crash): varying vec2 ...
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1answer
935 views

Getting the real fragment depth in GLSL

I am trying to write a simple GLSL shader that just renders the real (not normalized) depth of a fragment as a floating point value. So far, I've figured out how to get the depth of a vertex, and ...
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2answers
155 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
446 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 ...
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1answer
486 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 ...
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1answer
93 views

Way to avoid excessively bright objects with specular lighting?

I have a typical Phong shading with specular light. I have all the parameters tuned so to give appropriate highlights from a point light source. Now the problem I have is a new object that has a large ...
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1answer
480 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
283 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. ...
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1answer
256 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
214 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 ...
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1answer
193 views

Why are some of my normals facing away from the camera?

I'm trying to use WebGL to render some simple models, and I'm running into issues where pixels near the edge of my model are passing normals to my fragment shader that point away from the camera. This ...
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1answer
111 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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1answer
1k views

GLSL billboard move center of rotation

I have successfully set up a billboard shader that works, it can take in a quad and rotate it so it always points toward the screen. I am using this vertex-shader: void main(){ vec4 tmpPos = (MVP * ...
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2answers
2k views

Draw wireframe overlay of model in GLSL

I have a 3D model that has a GLSL script, and I want to draw a line on each border of its polygons in the fragment shader. What should I do? Note: I am using Ogre3D, so I can't use OpenGL's ...
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1answer
110 views

Vertex and Fragment Shader worldNormal

How to access/calculate worldNormal in a Vertex and Fragment shader ? Thanks a lot !
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1answer
388 views

GLSL Shaders-> How to manage?

As your game get's bigger and bigger, you will use more and more different shader effects. Let's take an easy example: I have clouds in my voxel-based world, and I want to give it a blue-ish tint ...
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1answer
232 views

texture movement stutters

Hey I at the moment I have got my texture to move however it stutters as I increment by 0.001 every second. My animation is done via FPS if that make sense and here is some code FrameCount++; ...
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2answers
446 views

LWJGL Game crashes on some other machines [closed]

I just tried running my game on a friend's laptop, but for some reason it crashes. The exported .jar runs fine on my machine, and some others too. I can see that is has something to do with the ...
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1answer
1k views

vec4 for vec3 multiplication while calculating the specular value

I'm following this tutorial to calculate the specular color of a vertex. I use OpenGL 2.1 with GLSL version 120. This is the formula that I apply: spec= (R*eye)^s * Ls * Lm With: ...
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1answer
317 views

OpenGL RTT FrameBuffer question and Rendering to texture while sampling it

What i need to do: Blur the selected texture and pass the texture to another effect for postprocessing. Notice that i want one texture passed all over. How do i want to do this: Bind the FBO ( ...
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2answers
778 views

GLSL light coloring blocked surfaces

I have created a very simple lighting shader. It currently only supports point lights, but it lights up surfaces that are completely blocked from the light. I know why, but I want to know how I can ...
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1answer
37 views

Making a GUI shader in GLSL c++/opengl/freeglut

How do you make a shader that will draw ontop of everything else? Im using an approach where I draw square faces in 3d space to simulate a 2d box, but when I make a 3d object, it will clip over the 2d ...
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1answer
44 views

Solution for Shipping Optimized and Minified GLSL?

I've tried to find a reputable optimizing compiler for GLSL that takes source shaders, performs what optimizations it can statically assume, and outputs a minified GLSL file with optimizations, ...
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1answer
62 views

Black Screen when using High-Performance NVIDIA Processor

I have an issue where my program renders a black screen on other computers. I narrowed it down to when a different graphics card is being used. When I run the program using Integrated Graphics ...
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1answer
50 views

GLSL Shader not compiling (Android & LibGDX) and no log available

I'm trying to get a "ripple"-shader working for OpenGL ES 2.0+ (using LibGDX). However, I can't get it to compile, and for some reason ShaderProgram.getLog() returns an empty string even though the ...
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1answer
45 views

OpenGL: strange thing with depth and text rendering

TL;DR I render a scene with M,V,P matrices as always. Than I render something (in this case - text) without any matrices and using separate shaders pair on coordinates with Z = -1. Somehow it's ...
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1answer
186 views

Help me understand this vbo/rotation, and how its done opengl c++

Im pretty new to opengl, and I just cant figure out how to rotate this vbo/vao in 2d space. This is how I bind my coordinates: float points[] = { 0.0f, 0.10f, 0.0f, -0.10f, -0.10f, 0.0f, ...
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1answer
108 views

Draw cube in glsl shader

I am working on a voxel engine. Currently my cubes are rendered as vbos. I thought, it may be better to load only the cooridinates of voxels to the shader and make it draw a cube itself. Can someone ...
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1answer
103 views

Processing through multiple shaders (LWJGL/Java/OpenGL)

Very simple question: Is it possible to process a vbo through different shaders? If so, how? What I want is sth like this: reflectionShader.bind(); //starts shader reflectionShader.load(some_values); ...
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2answers
101 views

Passing data into a vertex shader for perspective divide

In OpenGL and GLSL, I am just learning about perspective projection and the vertex shader. However, I am a little confused about what data actually needs to be passed to the vertex shader, and what ...
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2answers
114 views

How do I start and stop a GLSL shader?

Is there a way to start and stop a shader?. I want to use this shader to sweep once over my texture and then stop. Does anybody know how to do that? void mainImage( out vec4 fragColor, in vec2 ...
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2answers
109 views

Problems with Rotation Matrices on Certain Axes

Here is what my rotation matrix looks like: public Matrix4f initRotation(float x, float y, float z) { Matrix4f rx = new Matrix4f(); Matrix4f ry = new Matrix4f(); Matrix4f rz = new ...