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

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2
votes
1answer
6k views

Unity custom shaders and z-fighting

I've just readed a chapter of Unity iOS Essential by Robert Wiebe. It shows a solution for handling z-figthing problem occuring while rendering a street on a plane with the same y offset. Basically ...
2
votes
3answers
1k views

Rain effect using DirectX 9 capabilities

Is it possible to achieve something similar to nVidia's rain demo using only shader model 3.0 capabilities? If yes, could you point out a few documents/web resources that are suitable candidates and ...
0
votes
1answer
1k views

How to convert Maya shaders and Renderman shaders to GLSL?

I know this 2 products but i have never used them for production, since I have a bunch of cool shaders i would like to use them under OpenGL with GLSL but i don't know where to start. If it's not ...
2
votes
1answer
282 views

What are the factors that determine the default frequency of a shader call?

After i have been played for some days with various vertex and fragments shaders seems clear to me that this programs are called by the GPU at every and each rendering cycle, the problem is that I ...
13
votes
1answer
3k views

Should I distribute shaders in a compiled form or in plain text?

Having an application that uses shaders that have been wrote in GLSL, what is the best strategy for the distribution in the real world and for the desktop and mobile? I'm aiming to distribute this in ...
1
vote
1answer
149 views

Only apply Advanced Graphics on high FPS Dynamically

I wonder why not prevent lags by only appying advanced optional graphics stuff when the FPS are high at time. So The game could use simpler or even no shaders and skip decorative models some time. It ...
10
votes
1answer
3k views

GLSL, all in one or many shader programs?

I am doing some 3D demos using OpenGL and I noticed that GLSL is somewhat "limited" (or is it just me?). Anyway I have many different types of materials. Some materials have ambient and diffuse color, ...
23
votes
3answers
19k views

outline object effect

How can I achieve an outline effect similar to the ones found in League of Legends or Diablo III? Is it done using a shader? How? I would prefer answers that are not tied up to any particular ...
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 ...
0
votes
1answer
317 views

Dynamically change shader syntax with the help of C++

I'm starting with the programmable pipeline and the shaders in C++ for OpenGL 3.0+, i would love to be able to change some settings on the fly, for example replacing a function with another function, ...
5
votes
1answer
568 views

Dealing with alpha for 2D per pixel lighting

Right now I've got a simple light shader. Every bitmap I draw goes through it to make up the scene. I only draw quads. texture tex; sampler2D s = sampler_state { texture = <tex>; ...
5
votes
3answers
927 views

Finding out what pixel on the screen the fragment falls on

In my 2D game, I render tiles. I want to do lighting without needing an extra buffer the size of the screen. Either in glsl or hlsl, what could I feed to the shader each time I render a bitmap so ...
1
vote
0answers
306 views

Full screen shader causes performance hit

I basically want to have a shader run that can do something like toon shading, or grayscale the whole screen, or radial lighting. To do this, I create a new bitmap each time the display resizes that ...
0
votes
1answer
156 views

My blur gets ugly when radius too high

I have the following h and v blur: Horz texture tex; sampler2D s = sampler_state { texture = <tex>; }; int tWidth; int tHeight; float blurSize = 9.0; float4 ...
1
vote
1answer
221 views

Can I limit the number of shader units used by my video card?

Can I limit the number of shader units used by my video card? (A shader unit is the part of the hardware which can execute a shader program, where each unit runs in parallel). I'm interested in this ...
4
votes
1answer
3k views

Access vertex data stored in VBO in the shader

If I wanted to store extra data in a VBO for skinning (indices for indexing into an array of matrices of bones and floats for applying weights to those bones) How would I go about accessing that data ...
2
votes
2answers
2k views

My hlsl shader cannot unroll a loop?

I have this shader: texture tex; sampler2D s = sampler_state { texture = <tex>; }; int tWidth = 1; int tHeight = 1; int blurLength = 3; float4 ps_main(VS_OUTPUT ...
6
votes
3answers
1k views

XNA shader compiler error in release mode

I'm having a hard time figuring out if I'm doing something wrong, or if there is a bug with Visual Studio. I want to pass a float into my pixel shader, clamp it to a value, and then return it as part ...
11
votes
4answers
7k views

Debugging Shader Code?

I'm writing a game engine, and when I use a perspective camera I get a black screen. I am not going to ask exactly why this is because there would be a lot of code to share and, frankly, I think ...
1
vote
1answer
716 views

how to modify shadow mapping in “3D Graphics with XNA Game Studio 4.0”? [closed]

So I've been following the tutorials from the book Sean James's "3D Graphics with XNA Game Studio 4.0", and have been doing fine until i reached the shadow mapping part. in this book it creates point ...
2
votes
2answers
3k views

OpenGL ES high-quality 2D scaling

Let's say I'm making a 2D game and I want to implement a zoom in/out feature. Normally this is as simple as modifying the projection matrix to get more or less of the world to show. However, this ...
1
vote
3answers
1k views

Shaders not linking correctly

I'm writing a rather simple "ShaderManager" which aids me with loading shaders in Open GL, altough I am having a few issues: The shaders don't link correctly The the attributes don't bind Here's ...
-1
votes
1answer
1k views

Vertex shader are evil for performance?

I found that the vertex shaders are sometimes very useful, especially because they can generate geometries and extract and use a lot of informations from just 1 image. The problem is that my project ...
0
votes
1answer
223 views

Drawing at negative coordinates in XNA?

I am trying to make a 2D isometric RPG and I kind of hit a wall when it comes to lighting. I was thinking of using shaders, if I manage to understand them.The problem I am anticipating is the presence ...
1
vote
1answer
1k views

Shader authoring/editing tools for GLSL ES

Since Render Monkey has been discontinued (perhaps due to the complexity of today's shading languages), there are few successors that can match its functionality. Is there any useful tool for material ...
1
vote
3answers
702 views

Writing a shader once without using CG?

Is there a tool that can convert a fragment shader from hlsl to glsl or glsl to hlsl? I do not want to use cg since it is not able to work on mobile platforms. Is there a tool that can make it so I ...
2
votes
1answer
623 views

Efficient manager/controller for uniform and/or attribute variables in a rendering engine

Most engines on the market have their drawbacks and it's difficult to find a simple/light-weight one that's open-source and doesn't have to put you through a rather complex learning process. Writing ...
4
votes
0answers
681 views

How to reproduce the 3ds Max Gradient Ramp effect? [closed]

The material definition of a mesh is composed of these three components: Self-Illumunation, Refletcion and Refraction. Each of these components has a Gradient Ramp as a map and the mapping mode is set ...
10
votes
1answer
632 views

Special relativity shader in GLSL

I'm trying to implement a GLSL shader which helps understanding special relativity Lorentz Transformation. Let's take two axis-aligned inertial observer O and O' . The observer O' is in motion w.r.t ...
1
vote
1answer
2k views

GLSL - rewriting (geometry) shader from #330 to #130 version

I'm having trouble running example from: https://raw.github.com/progschj/OpenGL-Examples/master/07geometry_shader_blending.cpp My graphics card supports only #130 shaders version so I have to rewrite ...
2
votes
2answers
621 views

Lighting problems with Terrain

I'm in the process of learning Open GL and am having issues with lighting on my Terrian, I don't know if the issue is related to how I calculate my normals or the shader itself (I am using the shader ...
1
vote
1answer
436 views

Intercepting DirectX calls and optimizing the overal performance of games

I would like to use a DirectX proxy dll to intercept (and possibly optimize) the graphics calls being made by normal PC games. I am going to "screen cast" a game with ffmpeg or something similar and ...
1
vote
1answer
2k views

How to draw reflection of shaded objects in OpenGL?

I am trying to draw a scene with objects floating around and a mirror among them to reflect the objects in front of it. I managed to draw the reflection properly when the floating objects aren't ...
2
votes
0answers
316 views

Kinect User Silhouette Shader

I have this usermap from kinect's depth data (size is 320x280) and i want to display it on my game. The problem, of course it's ugly (first image) and i want to have beautiful effect like in the ...
6
votes
1answer
6k views

GLSL if-else statement unexpected behaviour

This question is related to this other one I asked a few days ago. Because I have finally get to the bottom of the issue, I have rather preferred to open a new question with a more detailed ...
4
votes
2answers
2k views

XNA 4.0 - Normal mapping shader - strange texture artifacts

I recently started using custom shader. Shader can do diffuse and specular lighting and normal mapping. But normal mapping is causing really ugly artifacts (some sort of pixeling noise) for textures ...
0
votes
1answer
615 views

Does anybody know of any resources to achieve this particular “2.5D” isometric engine effect?

I understand this is a little vague, but I was hoping somebody might be able to describe a high-level workflow or link to a resource to be able to achieve a specific isometric "2.5D" tile engine ...
15
votes
4answers
5k views

Fixed-Function vs Shaders: Which for beginner?

I'm currently going to college for computer science. Although I do plan on utilizing an existing engine at some point to create a small game, my aim right now is towards learning the fundamentals: ...
4
votes
1answer
2k views

Multiplication for MVP matrices: Any benefits to doing so within the vertex shader?

I'd like to understand under what circumstances (if any) it is worth doing MVP matrix multiplication inside a vertex shader. The vertex shader is run once per vertex, and a single mesh typically ...
4
votes
1answer
2k views

OpenGL ES 2 shaders for drawing buildings and roads like Google Maps does

I'm trying to create a shader that'll give me an effect similar to what buildings and roads look like on 3D Google Maps. You can see the effect interactively if you enable WebGL at maps.google.com, ...
8
votes
3answers
790 views

What exactly can shaders be used for?

I'm not really a 3D person, and I've only used shaders a little in some Three.js examples, and so far I've got an impression that they are only being used for the graphical part of the equation. ...
5
votes
2answers
2k views

Should the modelview and projection matrices be calculated in the shader or on the CPU?

At minimum I would have a camera with rotation and world position; projections parameters such as angle of view and perspective vs. orthographic; and meshes with scale, angle, and world position. ...
2
votes
1answer
2k views

Drawing simple geometric figures with DrawUserPrimitives?

I'm trying to draw a simple triangle based on an array of vertex. I've been searching for a tutorial and I found a simple example on riemers but I couldn't get it to work. I think it was made for XNA ...
1
vote
1answer
197 views

Blur gets displaced compared to original image

I have implemented a SSAO and I'm using a blur step to smooth it out. The problem is that the blurred texture is slightly displaced compared to the original. I'm blurring using a 4x4 kernel since that ...
2
votes
1answer
699 views

How do you create a cbuffer or global variable that is gpu modifiable?

I'm implementing tonemapping in a pixel shader, for hdr lighting. The vertex shader outputs vertices with colors. I need to find the max color and save it in a global. However when I try and write ...
7
votes
2answers
4k views

Updating texture memory via shader?

What the title says.Is it possible to update a texture via a glsl shader ? Something like : //Read vec4 Pixel = texture2D(TextureID,gl_TexCoord[TextureIndex].st); //Write to texture memory ? vec4 ...
3
votes
1answer
459 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. ...
1
vote
1answer
584 views

OpenGL Tessellation makes point

A little problem with my tessellation shader. I try to implement a simple tessellation shader but it only makes points. Here's my vertex shader : out vec4 ecPosition; out vec3 ecNormal; void ...
1
vote
2answers
256 views

What could cause a pixel shader to paint outside the lines of the vertex shader output?

From what I understand, the pixels that a pixel shader operates on are specified implicitly by the SV_POSITION output (in DirectX) of the vertex shader. What then could cause a pixel shader to render ...
4
votes
1answer
1k views

Bitwise operators in DX9 ps_2_0 shader

I've got the following code in a shader: // v & y are both uints nPixel = v; nPixel << 8; nPixel |= y; and this gives me the following error in compilation: shader.fx(80,10): error ...