A programming language for OpenGL shaders.

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4answers
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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.
1
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1answer
352 views

Positioning a texture inside a 3D object with GLSL

I have a 3D object in my scene and a texture that is the same size of the screen (a render to texture). Is there a way to make the object act like a "mask" for the texture(using glsl), so the texture ...
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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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2answers
5k 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 ...
6
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1answer
590 views

Fast and simple attenuation from a flaming torch

I have a single point light-source which is a flaming torch. I compute the distance from the light accurately. I am not trying to have a particularly realistic torch effect, but I will be moving the ...
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1answer
4k views

Why does my GLSL 1.20 shader not work with an OpenGL 4.0 driver?

I'm just starting out with OpenGL on Linux. In order to write future-proof code, I explicitly wrote code for OpenGL 4.0 Core Profile in the first place, thus the shaders are GLSL 4.0. That worked ...
1
vote
1answer
814 views

glsl applying shader

I want to use a shader just for learning purposes. But i have a few questions about it. I have the following code: Vertext shader: const float Eta = 0.66; // Ratio of indices of refraction ...
5
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1answer
426 views

Raymarching artifacts

I was playing with raymarching using distance fields in GLSL sandbox and got stuck with a strange problem with artifacts. Click here and take a look at the spheres generated in corners, they have ...
26
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4answers
21k views

Using multiple shaders

I'm currently studying opengl shaders but I can't figure out something: how to apply different shaders to the objects, for example, a teapot rendered using toon shader and another one in the same ...
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4answers
569 views

What is a right datatype in C++ for OpenGL scene representation with use of GLSL

I am programming in C++ OpenGl with GLSL. Until now I have been using a data structure that is composed of std::vector filled with structures of vertexes and with their parameters (position , normal, ...
10
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1answer
909 views

How do I create good looking plasma explosion effects?

Is this just a billboard quad with a bloom shader?
10
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3answers
2k views

Go pure OpenGL or GLSL? [closed]

I got interested in studying graphic programming so the obvious entry point was to learn OpenGL. But gathering scattered information around forums and sites, it seems that a pure OpenGL implementation ...
8
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1answer
6k views

What do the components of gl_TexCoord[0] mean?

What are the differences between gl_TexCoord[0].s, gl_TexCoord[0].t gl_TexCoord[0].p and gl_TexCoord[0].x, gl_TexCoord[0].y gl_TexCoord[0].z ? I understand that gl_TexCoord[0].x, gl_TexCoord[0].y ...
5
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1answer
2k views

Optional samplers in shaders

I have a scene. Sometimes I draw untextured, coloured, semi-transparent triangles, sometimes I texture them, and I draw a lot of both in a fairly interleaved manner. In a fixed function pipeline the ...
1
vote
1answer
487 views

Setting the values of a struct array from JS to GLSL

I've been trying to make a structure that will contain all the lights of my WebGL app, and I'm having troubles setting up it's values from JS. The structure is as follows: struct Light { vec4 ...
2
votes
1answer
3k views

How can I write only to the stencil buffer in OpenGL ES 2.0?

I'd like to write to the stencil buffer without incurring the cost of my expensive shaders. As I understand it, I write to the stencil buffer as a 'side effect' of rendering something. In this first ...
3
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1answer
1k views

Renderbuffer to GLSL shader?

I have a software that performs volume rendering through a raycasting approach. The actual raycasting shader writes the raycasted volume depth into a framebuffer object, through gl_FragDepth, that I ...
1
vote
1answer
368 views

Why am I seeing streak artifacts on the cube map I'm rendering?

I'm getting strange streaks on my cube map when rendering to it. He is my code that is being called each frame: void drawCubeMap(void) { int face; glClear(GL_COLOR_BUFFER_BIT | ...
9
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1answer
8k views

OpenGL/GLSL: Render to cube map?

I'm trying to figure out how to render my scene to a cube map. I've been stuck on this for a bit and figured I would ask you guys for some help. I'm new to OpenGL and this is the first time I'm using ...
4
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2answers
507 views

OpenGL, Offset and Camera Space

I was reading chapter 4 of the Arcsyntesis OpenGL tutorial when I came across this line in the GLSL shader. vec4 cameraPos = position + vec4(offset.x, offset.y, 0.0, 0.0); About it, the tutorial ...
5
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1answer
1k views

How does one get adjacency information in a geometry shader?

If you use triangle_adjacency as the input type of a geometry shader, do you need to do something on the client side besides make the primitive mode triangle_adjacency? Basically what I'm asking do ...
3
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1answer
1k views

GLSL Core Functionality Geometry Shader examples

I'm doing some research on geometry shaders and am having problems finding code examples/tutorials that does not use one of the extensions introduced before it was core functionality of OpenGL 3.2. ...
2
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1answer
1k views

Pygame water ripple effect

I have Googled for it but there are no ready scripts - as opposed to the same effect on Flash. I have checked the algorithm on The Water Effect Explained and also tested an implementation of the ...
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2answers
3k views

GLSL Shader Editors for Linux

Are there any good IDE's for linux that lets us edit GLSL shaders and visualize their effect? Note : Shader Designer By Typhoon Labs is a good option but I am looking for alternatives as this ...
11
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2answers
8k views

How can I create an efficient bloom shader with GLSL?

I have searched the net for resources related to rendering a bloom effect using GLSL, but haven't found anything. Although the tutorial at Philip Rideout's website is a good one, it performs very ...
4
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1answer
642 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 ...
6
votes
3answers
517 views

shadowing billboards

I have a lot of billboarded 3D spheres (they have a heightmap so work properly with depth and penetration; although each is made of just a quad (with slight distortion), they look and feel and are ...
6
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2answers
3k views

Using a GLSL fragment shader to draw a texture in the middle of a quad

I'm not sure how possible this is, but I'm trying to use a fragment shader to draw a portion of a texture in the middle of a quad. This is all 2D. The quads consist of four vertices from (0, 0) to ...
3
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1answer
544 views

moving glDepthMask into a shader

Can a fragment shader make per-fragment decisions on whether the fragment updates the depth buffer or not, even if the fragment is not discarded and the color is written?
2
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4answers
1k views

Multiplatform GLSL shader validator?

Im working on a multiplatform (Pc,Mac,Linux) game that uses shaders quite extensively. Since we do not have any funding, it is pretty hard to test our game on all possible hardware configurations. ...
2
votes
1answer
386 views

Learning GLSL: What's a good intermediate project to work on?

I know the basics of OpenGL and I'm starting to love computer graphics more and more. I have a computer science background and have been programming for 5 years. I've been reading the orange book and ...
3
votes
2answers
3k views

computing gl_FragDepth

I am trying to draw spheres using a billboard, so I have a normal map with a z component that I am sampling in my fragment shader. I just need to add this z component to the depth of my fragment to ...
6
votes
1answer
4k views

GLSL - Rewriting shaders from #330 to #130

I recently created a game (LD21) that uses a geometry shader to convert points into textured triangles/culling. Since I was under the impression that the support for #330 was widespread I only wrote ...
1
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1answer
752 views

GLSL woes involving texturing

I'm a beginner to OpenGL and GLSL especially, and I'm having a lot of trouble getting textures to display via shaders. My shader code compiles without any warnings or errors, but I seem completely ...
22
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4answers
7k views

Why is programmable pipeline( GLSL ) faster than fixed pipeline?

So I'm teaching myself GLSL and am trying to figure out why it's suppose to be faster than the fixed function pipeline. The reason I am having a problem is that from my understanding , the shaders ...
37
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1answer
4k views

How can I reduce aliasing in my outline glow effect?

I'm trying to replicate the glowing outline effect in the Left 4 Dead game. The effect causes an objects outline to glow, even when the object is occluded. Here is a screenshot of the effect: I'm ...
5
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2answers
846 views

How'd they do it: sphere effects in Osmos

I'm curious how the sphere effects were done in Osmos from Hemisphere Games. Any ideas how the resolution independent zoom in was achieved? Edit, more specifics on questions: How do you render the ...
3
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0answers
958 views

Sampling from depth texture causes shader to stop working [closed]

I'm currently having issues with depth textures. When I sample from a depth texture it causes my other samplers to fail. For example, when I set gl_FragColor manually the depth buffer is correct. I ...
4
votes
2answers
516 views

Phone complains that identical GLSL struct definition differs in vert/frag programs

When I provide the following struct definition in linked frag and vert shaders, my phone (Samsung Vibrant / Android 2.2) complains that the definition differs. struct Light { mediump vec3 ...
6
votes
4answers
1k views

Spell Effects/Shaders

I want to be able to achieve spell effects that cause a fragmenting/discoloring effect on the sprite. The first couple seconds of this video http://www.youtube.com/watch?v=HNCFh7mkvuc shows what I ...
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2answers
914 views

How does OpenGL-ES 2 assemble primitives?

Two things I'm quite confused about. 1) OpenGL ES 2.0 creates primitives before the vertex shader is invoked. Why, then, does it not automatically provide the vertex shader the position of the ...
1
vote
1answer
503 views

Questions before I revamp my rendering engine to use shaders (GLSL)

I've written a fairly robust rendering engine using OpenGL ES 1.1 (fixed-function.) I've been looking into revamping the engine to use OpenGL ES 2.0, which necessitates that I use shaders. I've been ...
5
votes
1answer
304 views

How can I test shaders for nVidia on an ATi system?

I and our other devs have ATi graphics cards. However we have encountered that some shaders that compile without warnings on ATi don't compile at all on nVidia. The problems are trivial to fix, but ...
4
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3answers
3k views

How can I draw the depth value in GLSL?

I want to draw the depth buffer in the fragment shader, I do this: Vertex shader: varying vec4 position_; gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; position_ = ...
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vote
3answers
1k views

Is it possible to batch draw sprites that use different textures without using an atlas?

I've implemented a sprite batch class that uses a sampler array so that I can select a texture to use based on the gl_PrimitiveID. The idea was to be able to draw sprites that use different textures ...
6
votes
2answers
933 views

Casting a shadow over a whole scene with GLSL in 2D?

I'm making a (non-isometric) side scrolling 2D game and I want each fragment that I draw to cast a small drop shadow when it is near another object. What sort of algorithms are used in fragment ...
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2answers
6k views

OpenGL ES 2.0: Controlling Transparency in Fragment Shader

The following is the OpenGL ES 2.0 simple GLSL Fragment Shader, I use to place textures on polygons, to render 2D sprites. varying mediump vec2 TextureCoordOut; uniform sampler2D Sampler; void ...
1
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1answer
243 views

Can you have shader variables that vary per primitive?

A shader normally has values that vary per-vertex and values that vary per-fragment. Can you have values that vary only per primitive, such as per-triangle or per-quad?
11
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6answers
12k views

OpenGL ES 2.0: Repository of Quality Shaders

Could I kindly ask, to suggest me a repository of high quality OpenGL (OpenGL ES 2.0) vertex and fragment shaders, please? I am looking for pixel based ligting shaders (such as phong) and simmilar. ...
2
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1answer
528 views

Model in Blender GLSL to XNA HLSL

Is it possible to make model in Blender, with enabled GLSL, add multiple textures, etc, and then just load it in XNA, where's own HLSL? Will it work?