A programming language for OpenGL shaders.

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2answers
459 views

How can I optimize these GLSL bitwise operations?

I need the following part of my vertex shader simplified. Sb=Sb|((gl_VertexID&(128+1))<<9); Sb=Sb|((gl_VertexID&(512+4))<<6); Sb=Sb|((gl_VertexID&(2048+16))<<3); ...
3
votes
1answer
139 views

If-clause in GLSL

I read a few thing about, that in GLSL both sides of the if-clause is executed, so do you have any idea for a workaround for this one: uniform int uses_bones; uniform mat4[] bone_transformations; ...
1
vote
1answer
270 views

OpenGL/GLSL/LWJGL return value from shader

I'm trying to do some bone animation. I don't want the whole skeleton to be loaded to the GLSL shader every time, even tough it's not needed, because one vertex is parented to one bone, not more. My ...
1
vote
1answer
196 views

Can drawing to an FBO be done purely with a depth input texture, or do I also need a color attachment?

I am trying to implement Exponential Shadow Maps and I've got it almost working. The part I am stuck on is the "optional" separable Gaussian blur of the depth map to give soft-looking shadows. I am ...
0
votes
0answers
62 views

Trying to get the fragment shader to output a list

I am trying to figure out a way to get the Fragment Shader to output a list of gl_VertexID-s. I want to use the GPU to get a list of vertices in the viewing frustum. Is there any way I can get a ...
1
vote
1answer
147 views

Averaging normals, or tangents

I am using a library to load an obj but it doest compute the tangets for each vertex, which I need for normal mapping and pom. I computed my tangets, and bitangents, everything appears to be fine, but ...
0
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0answers
174 views

2D GLSL Lighting and Sprites

I'm trying to make a 2D game engine, and I really want to support ambient light as well as multiple point lights that you can define the color, intensity, radius, etc from uniforms in glsl shaders. ...
1
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0answers
181 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 ...
2
votes
1answer
84 views

What will happen if the argument of mix() or clamp() is above 1 or below 0?

There's two magnificent intrisincs: mix() in GLSL and clamp() in HLSL, which are used to implement linear interpolation. Let's say we have a variable: float v = ?; // where ? can be [-FLOAT_MAX, ...
0
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0answers
190 views

What limits the number of vertices the GPU can process per clock cycle?

I am currently experimenting with OpenGL to make my own game. I wrote some test code to see what are the limits of my GPU. I own a Geforce 840m. This essentially consists of a draw command ...
0
votes
1answer
248 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 ...
0
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1answer
1k 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 ...
0
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0answers
61 views

SFML - Rendering a torch with a fire animation [duplicate]

I have coded a 3D maze simulator in SFML using raycasting. However, I want to add a torch to the screen, so that the lighting seems more realistic. From my understanding, I would have to use ...
1
vote
1answer
377 views

How does an energy-conservative Blinn-Phong-Fresnel model work?

What is a plausible, basic equation/pseudo-code for energy-conservative Blinn-Phong shading, including Fresnel with a coloured light-source? The net gives so many alternatives that it's hard to ...
1
vote
1answer
297 views

How can I make this shader background more efficient?

I want to use a shader as a background for a mobile game. I'm using libgdx for my project. I've never written glsl before, but here's my attempt so far: http://glslsandbox.com/e#22332.13 On desktop ...
0
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0answers
268 views

C++ - SFML - OpenGL - GLSL - smooth waving texture

I have this shaders: Fragment: uniform float time; uniform sampler2D texture; void main() { float t = time; vec2 aux = gl_TexCoord[0].xy; // This would also make waving/deform the ...
1
vote
1answer
557 views

GLSL: Incompatible Types at Initialisation (and no available implicit conversion)

I'm recieving the following error when compiling my GLSL shader: Incompatible types in initialization (and no available implicit conversion) It occurs on line 94: int shadowMap = ...
1
vote
2answers
255 views

Optimized linear to sRGB GLSL

I'm currently using a simple implementation of linear to sRGB transform: float sRGB(float x) { if (x <= 0.00031308) return 12.92 * x; else return 1.055*pow(x,(1.0 / 2.4) ) ...
2
votes
0answers
337 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 ...
-1
votes
1answer
156 views

Encoding Float to RG/RGBA and Blending

Encoding a float value inside a RG or RGBA texture is very interesting and useful but it is also become quite useless when you use blending as the result and the values might be altered because of ...
0
votes
1answer
220 views

Render model with meshes with materials and/or textures

I'm making a model class that is using Assimp in the background. I want my models' meshes to be able to have a material and an optional texture on top of that. Right now I'm doing it like this: for ...
7
votes
1answer
3k views

How to implement this kind of ripples with a GLSL fragment shader?

So I have already implemented the reflection part: uniform sampler2D texture; uniform vec2 resolution; uniform vec3 overlayColor; void main() { vec2 uv = gl_FragCoord.xy / resolution.xy; if (uv.y ...
0
votes
1answer
131 views

Cubemap faces rotation in GS shader

I Can't get correct rotations for cubemap faces. Thats should come to geometry shader, from camera "view" matrix I want make 6 faces for my cubemap, but seems I can't get it correctly... My first ...
1
vote
0answers
130 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 ...
2
votes
1answer
310 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(); ...
1
vote
1answer
274 views

How to calculate reflection vector from point sprite sphere?

So far I achieved building a cube map following this tutorial. Then I drew three points using glDrawArrays(GL_POINTS,0,3) and calculate the normals based on a sphere. To compute the incoming light ...
0
votes
1answer
266 views

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 ...
2
votes
1answer
145 views

Failing to move exponential depth term to depth shader in exponential shadow mapping

I'm playing around in my little toy project to see if I can understand how exponential shadow mapping works. To begin, I have the following two fragment shaders: Light depth texture shader ...
-1
votes
1answer
161 views

how to turn (or solidify) water or fuild into solid material (Renderring Effect)

i want to implement an effect like this. for example, let's assume the clay are made of particles. liquids of clay flows for a while, then it becomes dry and rest.finally those particles becomes only ...
4
votes
1answer
1k views

C++ OpenGL ShadowMap Issue/Artifacts

I am currently implementing basic shadow mapping in my C++ Custom Engine using GLSL 4.10. It is currently working with basic PCF anti-aliasing and very minimal reduction for unwanted artifacts. Here ...
0
votes
1answer
83 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 ...
-1
votes
1answer
244 views

How to optimize my lighting shader?

I want to create a lighting effect on a gray-scaled world using cocos2d-x. What I've done is creating a layer which runs a shader program that receives light positions and radiuses as input and ...
0
votes
2answers
69 views

Overload how an object instance of a class is treated when used

So I've made this struct that encapsulates a glm::vec4. This is because vec3s are treated as 16-byte in GLSL, but I don't want to assign a vec4 if I only really need 3 components. Anyway, my question ...
0
votes
1answer
210 views

Ray casting problem using JOGL

I'm trying to port an old perfectly functioning ray casting implementation from my lwjgl project (FF pipeline) to a new project using JOGL and shaders. My problem is that my ray no longer intersects ...
0
votes
0answers
199 views

Artifacts rendering high-poly procedural meshes with OpenGL

I am having some issues when rendering some procedural generated meshes. There are some really wierd artifacts when rendering high-poly count meshes (not that much actualy). I have been able to ...
3
votes
1answer
546 views

I want to render some surfaces in GLSL with normal maps, and some without

I have normal mapping working in my game, but I want to only use normal mapping for some surfaces, and not others. Right now, as far as I can tell, my shader is applying an incorrect normal of (0, 0, ...
0
votes
0answers
180 views

Dynamic VBO update possibly corrupting data?

I want to draw a line between two vertices. On a mouseclick the vertex data will change and I want to update the line to use the new values. I am using a VBO for this and it looks like the update ...
1
vote
1answer
307 views

How do I convert from rectangular to spherical coordinates?

This seems like a fairly basic and common problem. Is there a builtin way to achieve it or do I have to write the algorithm on my own? If I do, how should it work?
0
votes
3answers
539 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 ...
1
vote
1answer
80 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.
1
vote
1answer
632 views

Is it possible to use unnormalized texture coordinates from a GLES2 GLSL fragment shader?

I want to look up a texel from my GLES2 GLSL fragment shader using un-normalized texture coordinates (0-w, 0-h instead of 0-1, 0-1). The reason is that this texture is used as a look up table and I ...
0
votes
1answer
459 views

Uniform Block solve padding/alignment for vec3 in CPU struct

I have a struct on the CPU which I'm sending to a uniform block in my shader. After a bit frustration I finally got it to work. The problem I had was that vec3s are actually treated as 16-bytes, or in ...
1
vote
1answer
132 views

What is the fastest way to know if the current coordinate in screen-space is odd or even in GLSL/GLES2 frag shader?

I want to make a post-effect where every second column of pixels is colored differently, and I want to implement this as a GLSL fragment shader on GLES2. The question is what is the most effective way ...
1
vote
1answer
473 views

Basic terrain shader without using external texture

I have this: (Right now I have the height map in a x*x size 2D array and a 1D vector too.) What I am trying to achieve is something like this: Without using any textures, only plain colors. So ...
0
votes
0answers
29 views

Artefact in VSM as if GL_DEPTH_TEST disabled

I am trying to implement VSM and I incurred in a strange issue. I render them as follow: glUseProgram(shadowMapProgramID); glEnableVertexAttribArray(0); glBindFramebuffer(GL_FRAMEBUFFER, ...
1
vote
2answers
1k views

How can I pass a std::vector<Vector3f> to my shader?

I have a Vector3f type which has x, y, and z properties. I have a std::vector of these vertices which describe my terrain. I would like to pass these values to a vertex shader through a uniform ...
3
votes
1answer
233 views

Shader - Transmittance or Absorption

I am trying to create a transmittance or absorption shader (glsl, hlsl, cg, etc...) in realtime but I don't find any good tutorial or white paper about this subject. I only find offline rendering ...
2
votes
1answer
328 views

Is it possible to calculate the TBN matrix in the fragment shader?

Just from model position, model normal and texture uv?
0
votes
1answer
612 views

How to load and render PhysX 3.3 heightfield

I'm trying to load a PhysX 3.3 heightmap and render it with OpenGL using glm and glfw, but so far it doesn't seem to be working. I'm basing my code on the PhysX samples, and am also using FreeImage to ...
0
votes
1answer
148 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 ...