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

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4
votes
2answers
368 views

Geometry shader worldviewprojection

I'm writing a simple geometry shader to create 3D "primitives" in place of a single point. I am performing all of the world-view-projection conversions within the geometry shader after creating the ...
4
votes
3answers
633 views

OpenGL ES 2.0 - How to batch draw particles that have unique translations, rotations, scales, and alphas?

I've combined all of my vertex data for many particles into a single array. How would I batch draw all of those particles in a manner that preserves their unique translations? Any code examples ...
4
votes
2answers
557 views

Reflections based on distance from plane

Let's consider, for example, a surface like the volleyball court, we can see that legs and shoes of the players are reflected, with a blur effect, but body and stadium don't (as each object not near ...
4
votes
2answers
532 views

Phone complains that identical GLSL struct definition differs in vert/frag programs

When I provide the following struct definition in linked frag and vert shaders, my phone (Samsung Vibrant / Android 2.2) complains that the definition differs. struct Light { mediump vec3 ...
4
votes
0answers
549 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 ...
3
votes
3answers
2k views

How can I make a shader effect that looks like a lightly shaded pencil drawing?

I want to make a shader effect using OpenGL ES 2.0 that looks like this image: I'm not sure if this image was painted or is the result of some filter, but I want to create a shader that produces ...
3
votes
4answers
7k views

How do multipass shaders work in OpenGL?

In Direct3D, multipass shaders are simple to use because you can literally define passes within a program. In OpenGL, it seems a bit more complex because it is possible to give a shader program as ...
3
votes
1answer
388 views

I want to render some surfaces in GLSL with normal maps, and some without

I have normal mapping working in my game, but I want to only use normal mapping for some surfaces, and not others. Right now, as far as I can tell, my shader is applying an incorrect normal of (0, 0, ...
3
votes
1answer
428 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
2answers
777 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. ...
3
votes
1answer
341 views

What is the maximum number of shaders I can have in OpenGL 4?

What is the maximum limit of shaders I can have on the GPU? With 1000 different objects, I might have 1000 * 5 shaders (vertex, tcs, tes, geo, frag) on the GPU at a time. Though only one will be ...
3
votes
1answer
859 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
926 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
1answer
565 views

Rendering different materials in a voxel terrain

Each voxel datapoint in my terrain model is made up of two properties: density and material type. Each is stored as an unsigned integer value (but the density is interpreted as a decimal value ...
3
votes
2answers
1k 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
4k 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 ...
3
votes
1answer
118 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
217 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
1answer
537 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
971 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
7k 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
85 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
515 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
88 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
395 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
122 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
200 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
893 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
446 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
2answers
94 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
184 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
123 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
263 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
172 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
2k views

How to draw a Bezier line with shaders?

I found a shader code to draw filled Quadratic Bezier in http://http.developer.nvidia.com/GPUGems3/gpugems3_ch25.html How can use something similar to draw a Bezier line that follows the same path? ...
3
votes
1answer
646 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
194 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
419 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
304 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
126 views

Geometry Shader not generating geometry for some Vertices

I am playing with a geometry shader and I am wondering why it doesn't generate geometry for each vertex in all meshes? I don't think this is a Cull problem because the same vertices generate ...
3
votes
1answer
94 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
2answers
289 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
275 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
122 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
384 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
212 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
3k 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
348 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
801 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 ...