a computer program that runs on graphics hardware and provides a high degree of control over how scenes are rendered

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3
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1answer
221 views

2D day night mapping

I'm looking for this kind of effect MINUS the lights and snow (Another problem). It needs to change depending on the time of year. Doesn't need snow or city lights. Now I'm pretty new to shaders ...
3
votes
1answer
840 views

How do I draw a circular portion of a texture within LibGDX using an OpenGL ES shader?

What is the simplest way to implement a shader to draw a circular portion of a full screen texture where the circle is dynamically resized as part of an animation using LibGDX? Is a shader even the ...
3
votes
1answer
94 views

Why does my PixelShader ignore color but respond to alpha changes?

I started teaching myself some DirectX a short time ago and found something I'm confused about. For some reason, I can only get the color of the model I'm drawing to vary between black and white, ...
3
votes
1answer
751 views

Compute Shader Memory Sharing

Ok guys I have had some pretty good success on this site but I feel that this is a pretty complex question. I am trying to do tile based deferred lighting using DirectX 11 and the compute shader. ...
3
votes
2answers
119 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 ...
3
votes
1answer
663 views

Using a switch command in one shader vs multiple shaders

If you have multiple shaders, could you instead of switching between shaders all the time just have one shader with a switch and each case will send you along to another shader function which you ...
3
votes
1answer
124 views

Do I need Texture Units when NOT using shaders?

Does calling glActiveTexture() even make sense when not using shaders? I only have to switch the textures before drawing a buffer with glBindTexture(), right?
3
votes
2answers
205 views

Shaders and Performance

I'm coding my first Shader in my little game engine, and I have some questions about it's performance and common approaches. Is the Shader code processed by the video card instead of the PC ...
3
votes
1answer
199 views

Why are some objects not rendering properly?

Here's a button I exported from Blender into a .x format: Now here it is in the game with BasicEffect applied to everything: And now with my custom shader: And there's the problem. While the ...
3
votes
1answer
1k views

Is the series of books “GPU Gems” still good for a modern OpenGL 3.0+ approach?

I noticed that this series of free books from Nvidia is really popular and well know in the devs world, the problem is that is simply old; you would recommend to read those 3 books to a developer that ...
3
votes
1answer
457 views

Complex shading using one single (small) texture

Recently I stumbled upon a demo reel in UDK about how one can attain beautiful results using just one (rather tiny) texture that's being sent to the shader pipeline. The famous link is this one. ...
3
votes
1answer
3k views

How to get the texture coordinate of a neighbouring pixel for a blur shader?

I'm still having some trouble to get my head around fragment shaders and doing some image processing on textures. The context is a 2D sprite: a simple texture painted on a quad. All done with OpenGL ...
3
votes
1answer
50 views

2D deferred lighting calculations not working

I have the following code for my HLSL pixel shader. Modified from another post here on GameDev (Link), but I have a few problems with it: // calculate UV and get texture and normal. float2 UV = ...
3
votes
1answer
94 views

Why can't I sample a texture in a vertex shader?

I'm old in Game Development but very new in shader writing. I just want a shader that transform from 1 texture to another. So I did start learning shader writing and wrote my desired shader. But ...
3
votes
2answers
143 views

How can I draw curves above a mesh surface?

I am making an animation of a deformed sphere that represents some aspects of the wave function in a hydrogen atom. I am starting with an octahedron that i push through a tessellation shader. The ...
3
votes
2answers
206 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() ...
3
votes
1answer
159 views

Desaturate texture using mask in OpenGL 2

I have a very large texture i am using as background and i want to apply a filter to a small part of it, the "small part" is defined by the alpha layer of another texture i have (which is still ...
3
votes
1answer
2k views

How to outline a 3D object with a cartoon style stroke? [duplicate]

How could I draw (stroke) the outline of a 3D object in a cartoon style with GLKit? I'm referring to something like this: However we can start with a simple line around the object and then try to ...
3
votes
1answer
523 views

When are HLSL literals taken as a float and integer?

float2 uv = float2(fX % 1, fY % 1) * 1/16; In the above example 1/16 is treated as a float, multiplying the float2 by 0.0625, but in: float2 uv = float2(fX % 1, fY % 1) * 1/16 + float2(1/16,0); ...
3
votes
2answers
206 views

Opengl shader questions

I'm currently building a shader that takes a 2D texture sampler and uses UV coordinates to map it. This works fine for all textured objects. However, I'm having a bit of a problem as I'm trying to ...
3
votes
1answer
794 views

How do I render a filled and stroked path using OpenGL?

I want to render a 2-dimensional geometric path consisting of Bézier curves and straight lines. Paths can be concave. What is the most efficient way to draw this using modern OpenGL? Can I do this ...
3
votes
1answer
515 views

How do I make a more or less realistic water surface?

I want to make a similar water surface like in this picture: I need the water surface in the same view than in the picture. Is it possible to work without shaders? I want to develop a little game ...
3
votes
2answers
370 views

Which will be faster? Switching shaders or ignore that some cases don't need full code?

I have two types of 2d objects: In first case (for about 70% of objects), I need that code in the shader: float2 texCoord = input.TexCoord + textureCoord.xy But in the second case I have to use: ...
3
votes
1answer
65 views

Do shader compilers typically know not to look up unused texture channels?

I have a texture that's from the color attachment of an FBO in OpenGL ES 2.0, so I have limited control over the number of channels in the image. Suppose I only need the color from the R channel of ...
3
votes
1answer
105 views

Underwater Shader Animation Help

I found an underwater (distort) effect and I got it to work but somehow I cannot make it animate given the offset here: Fragment Shader code: uniform sampler2D fbo_texture; uniform float offset; ...
3
votes
1answer
246 views

Monogame fails to load Effect

I'm currently porting an old XNA game over to MonoGame and everything (including custom shaders) build fine. However when i try to load the xnb file using content.Load<Effect>("BaseDraw"); I ...
3
votes
1answer
859 views

How to generate a RGB * a texture for a glow effect in GLSL?

I would like to create a glow effect in GLSL, there is a tutorial that explains how we multiply RGB * a : I have some questions : is it an operation that is in a fragment shader, where RGBa is ...
3
votes
1answer
492 views

How to read neighbor pixels in GLSL?

I'm using SFML 2.1, it's much more straightforward for me so I can jump directly to learning the shading language. I'm trying to do something similar to conway's game of life. I already learned that ...
3
votes
2answers
481 views

Possible to create transparency shader which doesn't stack alpha values

The image above best demonstrates what I'm trying to achieve. It's a transparent shader for objects, but wherever the objects with this shader intersect they don't add together but simply merge with ...
3
votes
1answer
981 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 ...
3
votes
2answers
1k views

How can I calculate spotlight lighting in Vertex/Fragment shader in Unity?

I've written a vertex/fragment shader for my game. It uses 3 textures and represents a floating water on the wall (so I have 1 texture for water, 1 for geometry and the last one is mask) so it looks ...
3
votes
1answer
376 views

Multiple pixel shader passes

I currently have a pixel shader that calculates the texture and I have another that calculates the light. I want another shader that does both. What I would ideally like to do is instead of creating a ...
3
votes
2answers
137 views

Are buffers in OpenGL associated with GLSL programs?

I have two different shader programs in my OpenGL code. 1- renders simple font using freetype 2- simple shader which draw primitive shapes. I sent both of them some data using buffers, I understood ...
3
votes
1answer
494 views

Odd blending result (semi-transparent 2d quad over 3D scene)

I'm working on a GUI library for my game, and I'm having problems with my blending. I have a 3D scene, which I render with glDrawArrays. In the fragment shader the alpha color is hardcoded 1.0f ...
3
votes
1answer
240 views

Messed up UVs in Unity3D for Android

All of my quads appear correctly textured on the Unity3D editor, a Motorola Xoom Android tablet, and on an iPad 2: But on our Samsung Galaxy Mini 2 smartphone they kinda look like this: I wrote ...
3
votes
1answer
4k views

How are vertex shader outs sent as inputs to the fragment shader?

I'm learning some OpenGL 3.2 way of doing things and I think it's quite great, I'm actually understanding more of shaders and non-fixed pipeline in 1 week rather than those 2 years I tried to learn ...
3
votes
1answer
379 views

cocos2d mask rotation

I've been experimenting with Ray Wenderlich's tutorial about masking sprite using shaders with cocos2D 2.0. It works pretty well but now I'd like to rotate the mask independently of the masked ...
3
votes
1answer
949 views

Monogame/SharpDX - Shader parameters missing

I am currently working on a simple game that I am building in Windows 8 using MonoGame (develop3d). I am using some shader code from a tutorial (made by Charles Humphrey) and having an issue ...
3
votes
1answer
725 views

Shadow-mapping xna

I've been trying to implement shadows in my game and I've been following quite a few tutorials online, mainly Riemers, but I'm always getting the same 2 errors when I'm drawing my models and setting ...
3
votes
2answers
738 views

WebGL geometry calculations

I have a dynamic surface in WebGL, that is animated in vertex shader. I want other objects to interact with this surface (for example, an object riding on dynamic terrain). What's the best way to do ...
3
votes
1answer
910 views

How'd they do it: TF2 payload cart glow?

How did the creators of TF2 make the glow on the payload cart visible through walls? Is it possible to implement this in Unity's shaderlab?
3
votes
1answer
2k views

OpenGL ES Basic Fragment Shader help with transparency

I have just spent my first half hour playing with the shader language. I have modified the basic program I have which renders the texture, to allow me to colour the texture. varying vec2 texCoord; ...
3
votes
1answer
92 views

How to blur entire scene but a specific spot in Unity?

What I want is basically: A way to blur every object/sprite on the scene, but have a "blur-free" circular zone, that can move. And everything that's behind that circular zone won't have the blur ...
3
votes
1answer
31 views

Libgdx - GLSL shader which uses mod doesn't seem to work properly on android

Through trial and error I've managed to come up with a scanline-ish shader I'm satisfied with. On my desktop testbed it looks like this: Basically, every 2nd(vertical) pixel is darkened. However, ...
3
votes
2answers
201 views

How to achieve a dynamic soft see-through hole effect in a wall with shaders?

I'm looking for a way to create a dynamic soft see-through hole effect for room walls. I know a few ways how to do it (for example multitexturing with second layer being the hole mask in screenspace), ...
3
votes
1answer
80 views

Strange depth map projection

I'm trying to implement depth-only SSAO and for that, I render a depth map into a texture and pass it to my SSAO shader which then uses it. The problem is that when I try to output the depth map ...
3
votes
2answers
197 views

Render Occluded pixels to gray color

In 3d space, objects can be occluded by another objects. By depth testing, the occluded faces are skipped rendering. Only the nearest(smallest) depth value pixels are drawn. But, sometime we need to ...
3
votes
1answer
440 views

Shader that draws just vertex points

The game I am developing is in unity and I want to make a shader which can be put on a mesh that only 'draws' color on each vertex point. I am not proficient with shaders, and out of all my searching ...
3
votes
1answer
200 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 ...
3
votes
2answers
92 views

In XNA 4, how can I access SpriteBatch's transformMatrix in my shader?

I would like to use a custom effect with a regular XNA SpriteBatch. I have a 2D camera which computes a transform matrix, so I need my shader to take this into account. I have put a world matrix ...