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

learn more… | top users | synonyms (1)

3
votes
1answer
728 views

How to achieve animated glow

I am trying to achieve something I've seen numerous times, but I don't know where to start from. I've come across numerous old effects, which I can't recreate. The said effects are the glow animations ...
3
votes
2answers
1k views

Which is worst: Too many VertexShader instructions, or FragmentShader instructions?

I want to have a better understanding of how to create shaders with optimal performance and realize where some bottlenecks can occur. Is it usually favorable (when possible) to delegate most of the ...
3
votes
1answer
100 views

Sine-based Tiled Procedural Bump

I am trying to implement this formula to generate bump but I am facing some issue. The result doesn't look the same it's much darker. Here is my result (without same parameters) but it is much ...
3
votes
2answers
4k views

2d metaballs with shader to give blobs of water effect?

I want to simulate blobs of water in a 2d game in Unity3d. One possible way of doing it is to use 3d metaballs moving in a 2d plane though this is very processor intensive. Do you think it would be ...
3
votes
1answer
1k views

Multiple Textures in Shader?

I have this (pseudo) code: unsigned int TextureLoc = glGetUniformLocation(programID, "objectTexture"); for(int i = 0; i < object->texturesCount; i++) { glActivateTexture(GL_TEXTURE0); ...
3
votes
1answer
1k views

Low-level GPU code and Shader Compilation

Bear with me, because I will raise several questions at once. I still feel, though, that overall this can be treated as one question that may be answered succinctly. I recently dove into solidifying ...
3
votes
2answers
2k views

Learning OpenGL GLSL - VAO buffer problems?

I've just started digging through OpenGL and GLSL, and now stumbled on something I can't get my head around this one!? I've stepped back to loading a simple cube and using a simple shader on it, but ...
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; ...
3
votes
1answer
328 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
1answer
287 views

How can I determine the extreme color values in a texture?

I am looking for a way to determine the most extreme color values for all of the texels in a texture. So for a texture consisting only of black and white texels, the extreme values should be (0,0,0) ...
3
votes
2answers
838 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 ...
3
votes
1answer
666 views

Matrix in constant buffer on the GPU contains NaNs but not on the CPU

I've got a shader with the following constant buffer: cbuffer ShaderParameters { matrix inverseViewProjectionMatrix; float4 cameraPosition; }; When using Visual Studio 2012's graphic ...
3
votes
2answers
1k views

implementing multi pass rendering in a game engine

I have done multi pass rendering before and understand how it works. I did a simple example which rendered a basic scene with shadows. This was all done in one file. Now I am trying to figure out is ...
3
votes
2answers
8k views

Can't update DirectX11 shader constant buffer [closed]

Alright, I'm currently making the transition from DirectX 10 to DirectX 11 (with very little help from the MSDN documention) and recently ran into a snag with updating a shader's constant buffer. My ...
3
votes
1answer
213 views

Writing a glow shader

I'm trying to learn writing shaders. And I've pieced together something that is kinda working. I want to create a transparent glow around a sphere. The problem I have is that I can't seem to alter the ...
3
votes
1answer
276 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
1k 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
100 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
866 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
137 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
750 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
200 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
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. ...
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
63 views

Super formula on shader

I'm using Shader-toy to experiment and try to learn a bit the shader science. As exercise I wan to replicate some of the wikipedia math plots. I've started with a Super Formula. What I want to ...
3
votes
1answer
61 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
364 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
1answer
121 views

Proper way to draw 1000 billboards that always face the camera

I have up to 1000 visible GameObjects with trivial plane meshes, which are essentially sprites/billboards and which should always face in the relative direction -camera.forward. There are so many ...
3
votes
1answer
590 views

masking with 3d object in unity

I have a 3d plane in my scene and some 3d objects behind that plane. So, i want to render only the part behind the 3d plane. So how should I do this, should I have to use custom shaders, plz help.
3
votes
2answers
154 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
217 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
165 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
605 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
222 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
856 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
553 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
395 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
29 views

Matte reflection effect in Unity?

I'm trying to achieve that kind of scene but in real time using Unity. It's basically composed of some primitives, a skybox, and a plane. I'm intrigued on how to do this effect in particular: ...
3
votes
2answers
136 views

Bullet holes on curved surfaces and corners

So right now I am making an FPS game where the gun creates bullet holes (plane with texture) on impact, but there is a problem with that, if I shoot at the edge the plane will stick out and also ...
3
votes
1answer
60 views

Upgrading Unity from 5.1 to 5.3.4 has broken game, specifically models made in Blender

I recently decided to upgrade Unity after putting it off for some time as I have a rather sizable project started in 5.1. I knew there would be some hurdles, however, I have had very little luck in ...
3
votes
1answer
89 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
143 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
273 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
1k 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
707 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
541 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
1k 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 ...