A programming language for OpenGL shaders.

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54 views

Set Render Target usage

I am using Unity and I have some difficulties about understanding the way Set Render Target works and how it can behave with the shaders. Is it possible to render a shader pass in multiple render ...
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0answers
36 views

glsl specular not working

ok, i'm a complete noob regarding shaders and all this, so i must be doing something really stupid, but i cannot get specular lighting to work. I've read a whole lot of different shaders on the ...
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1answer
149 views

WebGL half float equivelant?

I'm trying to find a half float for the purposes of doing math in a fragment shader, not trying to have a half float texture. Is there an equivalent of the half float data type in WebGL? I know you ...
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2answers
360 views

2D Hidden Object Silhouette Shader

Right now I am not using any depth information in my engine, but I just found out that it would be neat to be able to render the silhouette of important game objects that are "behind" something with a ...
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0answers
153 views

Confused About My Code Suggesting The Normal Matrix Is Equivalent To The ModelView Matrix

I'm learning environment mapping in OpenGL by following this page. In his vertex shader, the author calculates the vertex normal in eye space with the following code: nEye = vec3(viewMatrix * ...
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0answers
142 views

glGetUniformLocation returns 23724032

as the title says, I have a problem using glGetUniformLocation call that returns, for the following code, the value 23724032. I'm writing a little engine and the draw function of my models is: void ...
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0answers
306 views

Uniform Buffer Binding-points

I believe Uniform Buffers/Blocks has been the hardest thing to grasp in OpenGL. Hopefully this will be my final issue regarding this. I have created a uniform buffer that contain data of Light ...
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0answers
114 views

Blending Lightmaps and Dynamic Texture Shadows in HLSL/GLSL

I'm using Gile[s] as my lightmapper and my engine can execute GLSL/HLSL scripts. I would like to accomplish something like this for performance reasons. I was told that this technique can only be ...
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1answer
253 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
77 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
52 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 ...
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0answers
547 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.)], ...
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501 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 ...
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351 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 ...
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0answers
72 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 ...
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0answers
226 views

Different way to pass uniforms to seperate draws in glMultiDrawElementsIndirect

Given OpenGL version 4.3 and GLSL 430, what would be the best way to pass a matrix to each model in a draw call to glMultiDrawElementsIndirect? I am thinking of going the way of a TBO and indexing it ...
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0answers
108 views

Texture not visible on particles

This is the first time I am working with particles (GL_POINTS) I am using kinematic equations and controlling their movement in vertex shader. I am following an example given in OpenGL 4.0 Cookbook ...
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0answers
369 views

GLSL, Internal error: assembly compile error for fragment shader at offset 513 [closed]

My vertex and fragment shaders link correctly. When I try and link my shader program I get the error: "Internal error: assembly compile error for fragment shader at offset 513". Pastebin of fragment ...
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0answers
159 views

Bad texture on model with different GPU [closed]

I have some kind of distortion on the texture of my 3D model. It works perfectly well on an AMD GPU, but when testing on a integrated Intel HD graphics card it has a weird issue. I don't have a ...
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0answers
219 views

Matrix array doesn't seem to get populated [closed]

I'm trying to stream an array of matrices to a vertex shader, but it seems that only the first matrix works. What could be the problem? I suspect that I upload the matrices in a wrong way. C# ...
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1answer
479 views

How to have qt5 work on desktop like on mobile devices (es2, correct glsl version)?

I am looking for help/information concerning this issue : My work: I have an opengl es2 render engine that works on an iOS app. I almost managed to make it work by calling the same openGL rendering ...
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0answers
601 views

shader-based particle systems [closed]

I have a classic particle system where each particle is represented by a quad and, each time step, I move each particle. My target is webGL which means I don't have instancing, attribute divisors nor ...
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1answer
548 views

Multisampled Texture

i have some doubts with multisampled textures. In fragment shader, how to pass multiple samples? We use glTexImage2DMultisample instead of glTeximage2D. so, how to upload texture data? I want to ...
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1answer
359 views

fragment shader with SNORM textures

I want to apply SNORM texture by using GL_TEXTURE_3D as a target, what will be the fragment shader for the same? Also, what should be the data type of texture data?
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2answers
307 views

Low complexity shader to indicate the sides of a polyline

I have a bunch of polylines that I draw using GL_LINES. They can have thousands of points. They actually represent the separation of land and water on a map. I don't have complete polygons, just the ...
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0answers
300 views

Full screen shader causes performance hit

I basically want to have a shader run that can do something like toon shading, or grayscale the whole screen, or radial lighting. To do this, I create a new bitmap each time the display resizes that ...
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1answer
549 views

OpenGL Tessellation makes point

A little problem with my tessellation shader. I try to implement a simple tessellation shader but it only makes points. Here's my vertex shader : out vec4 ecPosition; out vec3 ecNormal; void ...
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0answers
462 views

How to setup my texture cordinates correctly in GLSL 150 and OpenGL 3.3?

I'm trying to do texture mapping in GLSL 150 and OpenGL 3.3 Here are my shaders I've tried my best to get this correct as possible hopefully this is :) I'm guessing you want to know what the ...
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3answers
1k views

iOS - pass UIImage to shader as texture

I am trying to pass UIImage to GLSL shader. The fragment shader is: varying highp vec2 textureCoordinate; uniform sampler2D inputImageTexture; uniform sampler2D inputImageTexture2; void main() { ...
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1answer
160 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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1answer
5k views

GLSL - Declaring global variables outside of the main function scope

Does it help to declare variables outside of your main function scope in GLSL? Do these variables actually get reused and is it more efficient? Here is the code in question: varying vec2 vposition; ...
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2answers
2k 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 ...
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1answer
205 views

Shader program compiles fine on Ati, fails on other vendors

Got a real annoying problem here. My shader program compiles fine on my Ati Radeon HD card, but on Nvidia and Intel it failes to compile. Vertex shader: #version 120 attribute vec3 in_position; ...
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4answers
2k views

Render 3D torus shape entirely in GLSL

I was wondering, is it possible to render a (3D) torus shape entirely in GLSL, i.e. without using vertex/index arrays? Suggestions are welcome, thanks.
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3answers
488 views

Phong lighting model unrealistic result

I am using OpenGL 2.1 and GLSL 1.20 . I am trying to compute the fragment color applying the Phong lighting model. This is the formula I have (the original formula has a summation, but since the ...
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1answer
134 views

Per vertex diffuse lighting not propogating across entire model

I'm not sure how to describe this problem so I've added a picture. When I add per vertex diffuse lighting to my model (just a field of cubes for simplicity) the lighting effect applies to each ...
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1answer
767 views

Problems when rendering code on Nvidia GPU

I am following OpenGL GLSL cookbook 4.0, I have rendered a tesselated quad, as you see in the screenshot below, and i am moving Y coordinate of every vertex using a time based sin function as given in ...
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1answer
3k views

Reinhard tone mapping and color space [closed]

I found two ways of doing tone mapping (first, second): //Ld - this part of the code is the same for both versions float lum = dot(rgb, vec3(0.2126f, 0.7152f, 0.0722f)); float L = (scale / ...
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3answers
455 views

Combine flat and smooth shading with a single model geometry

I need to be able to switch between smooth and flat shading interactively. Is there a way to do this efficiently with a single geometry? For example, smooth shading does not require duplicate ...
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1answer
126 views

Direction from the camera to the light source

I'm currently writing a game using OpenGL and GLSL. For the shader I need the direction from the current camera to the light source. The lightsource is given by lightSource.position as a uniform as ...
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1answer
351 views

What are the steps taken by this GLSL code?

1 void main(void) 2 { 3 vec2 pos = mod(gl_FragCoord.xy, vec2(50.0)) - vec2(25.0); 4 float dist_squared = dot(pos, pos); 5 6 gl_FragColor = (dist_squared < 400.0) 7 ? ...
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2answers
1k views

GLSL shader compilation

When i'm compiling a shader does it have to be complete? Can i use glCompileShader on a shader without a main() function? The OpenGL reference documentation has a nice writeup on program linking ...
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2answers
133 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
99 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
121 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
299 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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2answers
119 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
52 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
86 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); ...