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

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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 ...
4
votes
1answer
2k views

Shadow mapping does not work correctly using GLSL shaders

I'm a beginner in shadow mapping. I have in my scene two meshes : a cube and a floor. The scene is lighted by a single point light. Here's for the following display the light properties : ...
4
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1answer
593 views

Matcap and BRDF Shading

I just would like to know what's the difference between the Matcap shaders used in ZBrush for example and the Bidirectional Radiance Distribution Function shader. Are there two techniques the same ? ...
4
votes
1answer
882 views

How can I emulate point sprites in D3D11?

I have points which I pass to a vertex shader and then to a geometry shader, but now I want to get from the geometry shader a "bigger" point. So the point should get a "dadius" like it was possible in ...
4
votes
3answers
415 views

What techniques make next gen look so realistic [closed]

I have watch several gameplays from upcoming titles for ps4 and xbox one and I must admit that they are breath taking. Of course with new hardware, models will have more polygons and higher texture ...
4
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1answer
1k views

OpenGL, fetching the names of all uniform blocks in your program

I want to auto-bind uniform blocks with certain named values to certain binding points when I compile a shader. For example, I have some basic, default fixed binding points that are always used for ...
4
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1answer
6k views

Simple GLSL example to render a 2d textured quad?

I would really love to add shader support in my game , although i can't seem to find a SIMPLE example on how to setup opengl for using shaders. So i would like to ask : Does anyone knows if there are ...
4
votes
1answer
489 views

Direction vector in raycasting

When I read about how to get the direction vector in raycasting, for example on this site: http://www.daimi.au.dk/~trier/?page_id=98 They first render the mesh with front face culling and then with ...
4
votes
1answer
136 views

Lighting computation viewing direction

This is something that's really cooking my noodle. When I'm computing the light response for a material in my fragment shader, I'm using the standard 3 normalized vectors, in eye space: fragment ...
4
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2answers
467 views

Refractive blur in XNA?

I'm writing a 2D hack-and-slash game using XNA. I really want to implement the blur-like, refractive effect of a sword or such moving really quickly, seen in such games as Dust: An Elysian Tail and ...
4
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4answers
1k views

Enconding/Decoding bit value in Texture Alpha Channel

I am Rendering to a SurfaceFormat.Color. (R8G8B8A8) The alpha of this format has 8 bits and I want to be able to use those 8 bits as a bit field. For example, in one pass of my render, I want to save ...
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2answers
5k views

Changing the color of some fragment of a texture using shaders

Declarative programming language QML allows to connect the elements, their properties with universal variables in shader programs description. For these purposes there is such elements as ...
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3answers
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BlitzMax - generating 2D neon glowing line effect to png file

Originally asked on StackOverflow, but it became tumbleweed. I'm looking to create a glowing line effect in BlitzMax, something like a Star Wars lightsaber or laserbeam. Doesn't have to be realtime, ...
4
votes
2answers
53 views

DirectX11 Using Multiple Shaders

I currently have a scenario where I am rendering terrain with a shadow map. I have two passes, one for the depth buffer to create the shadow map (which is rendered to a texture) and a second that ...
4
votes
1answer
109 views

How do I do selective water surface rendering?

I have a shader that renders the "texture" of a very realistic water on a tile in the 3D world using a Frame Buffer. The problem is that, for example, I only want to render the part that isn't below ...
4
votes
1answer
68 views

Shaders: packing 4 textures into a single RGBA - slower?

I'm experiencing something really strange on an iOS mobile device. I have 4 textures, and after some profiling it seems, that doing four separate grayscale texture reads is faster, than reading the ...
4
votes
1answer
267 views

Why does my Outlined Diffuse 3 shader seem “detached” at a distance?

I'm using the Outlined Diffuse 3 shader from Unity and I'm having a problem with it: the outline looks great when the camera is near the object, but at a distance, it looks detached. From nearby ...
4
votes
1answer
286 views

PCF shadow shader math causing artifacts

For a while now I used PCSS for my shadow technique of choice until I discovered a type of percentage closer filtering. This method creates really smooth shadows and with hopes of improving ...
4
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2answers
1k views

Techniques for reducing terrain shader complexity

My terrain shader does quite a bit, but I don't know how to break it up in any way that will reduce my instruction count without removing key features of the terrain. It does the following: ...
4
votes
1answer
592 views

How can I handle the combination of multiple shader effects?

To be able to work efficiently with effects, is there a good way to combine multiple reusable "base" effects to achieve a more complex final result? For example, say I have an effect that handles ...
4
votes
1answer
584 views

Direct3D shader compilation fails with constant buffers

I've been particularly annoyed by a 'bug' for a couple days involving D3DCompile and vertex shaders with constant buffers. I'm assuming the bug is my fault (missing flag or small nuance of the poorly ...
4
votes
3answers
720 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 ...
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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 ...
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1answer
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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, ...
4
votes
1answer
119 views

How do I use openGL shader to reproduce this Photoshop implementation?

Here are my Photoshop actions: step1 - convert the current image into gray step2 - use the default parameters, as showed in the screenshot step3 - use the 『Hue/Saturation』 to convert the grey ...
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votes
2answers
66 views

Displaying smooth borders given a coarse grid-based map

I've been messing around with different algorithms trying to make a grid based map look smooth, I have tested with various shader based methods and wrote a few of my own but none of them look right. ...
4
votes
1answer
252 views

GLSL 2D Silhouette

I'm trying to render a silhouette of any entity behind foreground objects to indicate their position to the player. Here's an example of what I want to achieve, from Hyper Light Drifter: From what ...
4
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1answer
233 views

How do you add turbulence to a particle system using noise?

I have implemented a basic particle system using transform feedback in openGL, hoping to replicate a dust cloud. I have looked at methods of adding turbulence, such as vortices found here. But they ...
4
votes
1answer
374 views

Glow shader limited by the texture area

I'm working on a glow shader (for 2D engine Futile relying on Unity). It works OK but the effect is limited by the texture area. Except from adding a lot of empty pixels around the textures (which ...
4
votes
1answer
1k views

Faking 2d light using shader (Unity, Shaderlab)

Since the concept was difficult to explain in words for someone who's not quite familiar with shader, I described it in pictures. I'm currently using Unity and it seems Shaderlab is the best choice ...
4
votes
2answers
530 views

Calculate mipmap level in a loop with varying iteration?

How can I calculate the correct mipmap level in a shader? It needs to be used in a loop which runs a variable number of times so the compiler will not allow me to use Sample or the derivative ...
4
votes
1answer
925 views

Material System

I'm designing Material/Shader System (target API DX10+ and may be OpenGL3+, now only DX10). I know, there was a lot of topics about this, but i can't find what i need. I don't want to do some kind of ...
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votes
2answers
421 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 ...
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1answer
1k views

Where is the Shader Designer in Visual Studio?

I have Visual Studio 2012 Ultimate and I've been trying to access the Shader Designer. I searched through MSDN's text and Channel9's videos, but they keep failing to mention how to access it. Can ...
4
votes
2answers
604 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
566 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 ...
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0answers
71 views

Depth of Field Blur - Weighted sampling?

I've been studying Intel's fantastic article titled "An investigation of fast real-time GPU-based image blur algorithms" (here), where-in they state that Gaussian blur would need to be customized for ...
4
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0answers
49 views

Spherical Area Lights do not match reference

So I'm adding spherical area lights to my application, and comparing my results with mitsuba, I am getting some differences (left is my approach, right is mitsuba - a pathtraced reference): What I ...
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votes
0answers
43 views

Irradiance Map ( Irradiance environment map)?

As irradiance map is generated for every possible normal for all the texels in environment map (as every texel act as a light source) so that we can look up irradiance map, based on normal of fragment ...
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votes
0answers
75 views

Draw Edges in OpenGL

I use blender game engine, and blender use openGL for graphics. How can I draw lines around all 3D objects? Would this be a job for a filter? Mainly, I want my end result to look drawn. I found this: ...
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0answers
88 views

How to draw Shadow Volumes in one draw call?

I've got a simple app that draws 3D cubes using instance rendering and I'm implementing Shadow Volume. Each cube's vertex, uv, normal and index data are statically stored in 4 vertex array buffers. On ...
4
votes
0answers
439 views

Ashikhmin-Shirley model implementation: ugly result

I am trying to implement the Ashikhmin-Shirley model using these formulas: This is the GLSL 1.2 fragment shader code: uniform vec4 materialAmbient, materialDiffuse, materialSpecular; uniform ...
4
votes
0answers
688 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 ...
4
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0answers
1k views

Real time reflections [closed]

I just had a quick look at the new Crysis 2 DX11 update, and was quite surprised by some of the new features, especially the real time reflections on moving models. From what I could gather, there are ...
4
votes
2answers
575 views

How to place grass on custom terrain mesh

I made a custom terrain mesh and textured it, now I want to place grass on it, but I don't know how. I only find info about grass with the unity terrain. I am not even sure what exactly to look for. ...
4
votes
2answers
675 views

Unity - Water Cube (to 2D game)

I wonder if you can create a cube of water within the unity! I'm starting to use the Unity, and took a sought as to whether there was already something like this ... but have not found any tutorial ...
3
votes
4answers
2k views

Multiplatform GLSL shader validator?

Im working on a multiplatform (Pc,Mac,Linux) game that uses shaders quite extensively. Since we do not have any funding, it is pretty hard to test our game on all possible hardware configurations. ...
3
votes
2answers
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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
2answers
1k views

Optimizing gaussian blur with linear filtering

There's a few (here, and here) gaussian blur tutorials out there suggesting that you can essentially cut the number of texture lookups in a gaussian blur shader in half by exploiting the GPU's ...
3
votes
1answer
545 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, ...