2
votes
1answer
80 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 ...
3
votes
2answers
146 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() ...
0
votes
1answer
42 views

GLSL: Vertex attribute to int

I'm trying to write a shader which renders a multitextured geometry wihout rerendering the geometry with each texture. In my test I'm not using textures, I just convert the texture index to a color ...
0
votes
0answers
24 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
115 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, ...
0
votes
1answer
62 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 ...
2
votes
2answers
148 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 ...
0
votes
0answers
20 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
51 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 ...
1
vote
2answers
132 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 ...
0
votes
1answer
74 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
2answers
98 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 ...
1
vote
1answer
67 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 ...
-2
votes
1answer
71 views

List of GLSL ES built-in variables

I am writing an article on WebGL and three.js, I'm trying to search all the built-in variables available in the vertex and fragment shader. I've found many sites mentioning some, for example: ...
0
votes
1answer
195 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 : ...
1
vote
1answer
110 views

Gamma Space and Linear Space with Shader

I am using Unity and I can choose between two color space mode in the settings: Gamma or Linear Space. I am trying to build a Custom Lighting Surface shader but I am facing some problems with those ...
1
vote
1answer
280 views

gl_VertexID values when calling glDrawElements

I am struggling a bit to understand the values that gl_VertexID primitive contains when the vertex shader is executed. I have the standard modern rendering pipeline, in which after setting up ...
-1
votes
1answer
103 views

Unity's pack 4 floats

Linked to: GLSL pack floats into an RGBA texture I found EncodeFloatRGBA/DecodeFloatRGBA shader functions in Unity https://gist.github.com/hecomi/9580605 Now I try to figure out how they work. So I ...
0
votes
2answers
516 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 ...
1
vote
1answer
140 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 ...
2
votes
1answer
349 views

Alpha Blending: use the pixel with the smallest alpha

I'm writing a transparency shader where I need any intersecting textures to, wherever they overlap, take the texture pixel with the smallest alpha value and render only that, discarding the other ...
10
votes
2answers
980 views

Refractive glass shader

I have an infinite hexagonal floor, generated by tessellating a point grid in a tessellation shader pair: Note that this is a flat wireframe - the "shadows" are a lighting trick: Now, I'd like ...
2
votes
2answers
190 views

Does GLSL copy function arguments by value?

My question is about passing variables to GLSL shader. I'm not sure how that works and what are the performance implications. Say I got a function that accepts a "vec4" variable. The question is - is ...
1
vote
0answers
350 views

Normal mapping does not work correctly using GLSL and OpenGL [closed]

Hello I wrote a simple OpenGl program using GLSL to render a simple uv mapped plane using the normal mapping technics. Here's the display with a simple phong shading (without normal mapping) : Now ...
2
votes
1answer
145 views

How to work with smaller intermediate textures in OpenGL and GLSL?

I'm working on a project rendering water simulated through smoothed-particle hydrodynamics (SPH) with a non-photorealistic look to use in games. In the actual stage of the project everything about ...
0
votes
2answers
185 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: ...
9
votes
3answers
762 views

How can I create a glitter effect?

I am trying to create a glittering effect for my realtime shader but I don't know how. Here is one example, and another example. What technique can I use to implement this?
12
votes
1answer
2k 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
votes
1answer
214 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 ...
0
votes
0answers
31 views

Strauss model : no specular component [duplicate]

I implemented the Strauss model with the metalness, transparency and smoothness parameters, taking the formulas from the book "Programming vertex geometry and pixel shaders", this is how I implemented ...
0
votes
1answer
90 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: ...
1
vote
1answer
154 views

Separate shader programs or branch in shader? [duplicate]

I have a bunch of point lights and directional lights. Instead of checking the light type in the fragment shader and then branch for either point light calculation or directional light calculation, is ...
0
votes
0answers
131 views

How can I compute spotlight attenuation when I only have a spotlight cutoff angle?

I am trying to compute the spot light attenuation, though I don't have a spotCosCutoff (cosine of the spotlight cutoff angle) predefined variable in the shader so I have to compute it myself. This is ...
2
votes
0answers
253 views

Ashikhmin-Shirley model implementation: ugly result

I am trying to implement the Ashikhmin-Shirley model using these formulas: This is the GLSL 1.2 fragment shader code: uniform vec4 materialAmbient, materialDiffuse, materialSpecular; uniform ...
3
votes
2answers
394 views

When is the Z coordinate normalized in GLSL?

I thought that whenever you transform an object to world space, then view space and finally screen space, the last matrix you apply(the projection matrix) normalizes the z values between 0 and 1. ...
2
votes
1answer
313 views

Is this GLSL equivalent to this HLSL?

I was wondering if the both shader codes are equivalent. So the question is, is this GLSL vNormal = mat3(FUSEE_ITMV[0].xyz, FUSEE_ITMV[1].xyz, FUSEE_ITMV[2].xyz) * fuNormal; Equivalent to this ...
1
vote
1answer
174 views

Fragment shader seems to floor() imprecisely

I'm trying to interpolate coordinates in my fragment shader. Unfortunately if close to the upper edge the interpolated value of fVertexInteger seems to be rounded up instead of beeing floored. This ...
1
vote
0answers
203 views

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

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 ...
1
vote
1answer
690 views

GLSL 2d Per Pixel Lighting

First time writing shaders, and having a bit of an issue getting per-pixel lighting to work. The problem is pretty simple, but I'm afraid am doing something wrong here. Vertex Shader: #version 150 ...
1
vote
1answer
224 views

Bump mapping Problem GLSL

I am having a slight problem with my Bump Mapping project. Although everything works OK (at least from what I know) there is a slight mistake somewhere and I get incorrect shading on the brick wall ...
4
votes
1answer
785 views

Shadow mapping does not work correctly using GLSL shaders

I'm a beginner in shadow mapping. I have in my scene two meshes : a cube and a floor. The scene is lighted by a single point light. Here's for the following display the light properties : ...
0
votes
2answers
332 views

HLSL's Tex2D for GLSL?

I am trying to port a HLSL shader to GLSL. I'm just not quite sure how to convert this line: outA += Input.Color.a * tex2D(s, Input.TexCoord.xy + float2(-4.0 * pxSz.x * blurSize,0)).a * 0.05; ...
0
votes
2answers
955 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 ...
3
votes
0answers
412 views

Jet engine exhaust shader [closed]

How would I create a jet engine exhaust effect, as shown in the image from Fzero GX below. GLSL and OpenGL examples/solutions are prefered, though other resources are also welcome. Requirements ...
3
votes
2answers
72 views

Local shape color blending

I am trying to implement this in Unity 4 Pro. But I am stuck in the blending part. I don't understand how you could blend multiples textures/colors using multiples volumes on an object. How could you ...
0
votes
1answer
211 views

Creating a fragment shader to darken a white texture over time - OpenGL GLSL

So as a part of learning OpenGL, I've now decided to try and be a bit more creative with shaders, as part of a practice game I'm making using C/OpenGL. I'm completely new when it comes to working ...
3
votes
1answer
264 views

Directional light shader not behaving as expected

I coded my first glsl shader which manage diffuse and specular effects of a directional light. This is the fragment shader. #version 120 //matrix uniform mat4 model_matrix; //directional light ...
7
votes
2answers
5k views

GLSL Shader - Change Hue/Saturation/Brightness

I'm trying to change the hue of an image using a GLSL fragment shader. I want to achieve something similar to Photoshop's Hue/Saturation Adjustment layer. In the following image you can see what I've ...
1
vote
0answers
136 views

Matrix array doesn't seem to get populated

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# ...
0
votes
1answer
76 views

Vertex and Fragment Shader worldNormal

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