A program that runs on the GPU to determine output colors for pixels. Also known as a fragment shader.

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17
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2answers
4k views

Do I lose/gain performance for discarding pixels even if I don't use depth testing?

When I first searched for discard instruction, I've found experts saying using discard will result in performance drain. They said discarding pixels will break GPU's ability to use zBuffer properly ...
3
votes
1answer
460 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 ...
6
votes
1answer
2k views

2D Line drawing with Pixel Shaders

Recently I asked a question, what is the fastest way to render 2D lines using DirectX, and one of the answers mentioned this paper on Fast Prefiltered Lines which uses Pixel Shaders to accomplish ...
5
votes
2answers
3k views

How to implement color changing fragment shader?

I have a background of a given size and filled with a given color. I want to change it with an animation effect, starting from the center and spread out until it extends the whole background. The new ...
2
votes
1answer
633 views

How to use Pixel Bender (pbj) in ActionScript3 on large Vectors to make fast calculations?

Remember my old question: 2d game view camera zoom, rotation & offset using 'Filter' / 'Shader' processing? I figured I could use a Pixel Bender Shader to do the computation for ...
4
votes
1answer
1k views

How do I achieve supersampling / anti-aliasing in pixel shaders?

I am trying to write a couple pixel shaders to apply to images similar to Photoshop effects. For example this effect: But I noticed there is aliasing in my resulting image (the above image is a ...
4
votes
3answers
4k views

OpenGL additive blending not working as expected

I am trying to achieve additive blending with point sprites. When the sprites overlap, all I get is solid red, when I expect to get a smooth blend from red->yellow->white. My sprite texture has all ...
2
votes
2answers
887 views

How to set multiple times, in a single spritebatch, the same pixel shader parameter

I make a test with Effect class in XNA and I want to set multiple times the same parameters (MyParameter in below code). My code is : [...] //In Engine class Effect ShaderEffect = GameEngine....
3
votes
1answer
350 views

How to access the nth element in a 2d texture from a pixel shader in XNA

How can I access the nth element in a texture2d from a pixel shader? For example if I wanted to get the 5th vector4 from 10 x 10 texture2d
3
votes
1answer
110 views

Getting rid of texture bleeding

Edit: I figured out what problem I was facing, it's called Texture/Pixel bleeding, which I was not aware of yet. I posted an answer below consisting of a small description of the problem and a link to ...
1
vote
1answer
558 views

Color grading, shaders and 3d textures

I'm trying to implement color correction with the 3d lookup table. The lookup table is actually just a 2d texture 256x16 and consists of 16 squares which one is 16x16. When it comes to rendering, I ...
1
vote
2answers
916 views

Ward model implementation: specular component too weak

I'm trying to implement the Ward shading model, the anisotropic, computationally efficient version: This is how I made it: float alphaX=0.5, alphaY=0.5; // asinotropic roughness float ...
1
vote
1answer
381 views

DirectX11 pixel shader in pipeline is missing

I'm writing a program which displays a MS3D model using DirectX, and unfortunately, the result shows nothing on the screen. When I use the Graphics Debugger from Visual Studio 13, I notice that the ...
0
votes
1answer
305 views

How does OpenGL determine different outputs with shaders?

Lets say I have this GLSL code: #version 330 out vec4 outputColor; void main() { float lerpValue = gl_FragCoord.y / 500.0f; outputColor = mix(vec4(1.0f, 1.0f, 1.0f, 1.0f), vec4(0....