OpenGL is a graphics standard and API which targets the desktop and workstation markets. It is designed to be easy to accelerate with dedicated computer hardware, and hence most implementations give greatly improved performance over traditional software rendering. Currently, OpenGL is used for ...

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Library to load images into textures, Linux, C and OpenGl

I am looking for simple, self-contained C library for Linux to load images from files into OpenGL textures. The licence should be quite liberal: zlib, bsd, mit or something. I have found SOIL, however ...
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1answer
807 views

OpenGL vs physics?

I am very new to game programming and I am in my first project. I have come to a point that I need expert advice: Now for the game physics to be able to work on objects, it needs to know each ...
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4answers
699 views

I need help with 3d shading/lighting

How do you guys handle shading in a 3d game? I have a directional light source that shades one side of a tree made of cubes. The remaining 3 sides all get ambient shading only. So the 3d effect is ...
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3answers
677 views

Why is it possible to encounter a texture coordinate greater than 1 or less than 0

I'm studying a text about texture mapping and in the preparing to draw session, I read: Define the texture wrapping parameters. This will control what happens when a texture coordinate greater than ...
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1answer
4k views

GLSL Light (Attenuation, Color and intensity) formula

I'm implementing point lights in my Voxel engine, and I'm really struggling to get a good flow of light, from 100% near the light source to 0% at the light radius. I have 5 arguments for the ...
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3answers
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First time shadow mapping problems

I have implemented basic shadow mapping for the first time in OpenGL using shaders and I'm facing some problems. Below you can see an example of my rendered scene: The process of the shadow mapping ...
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1answer
1k views

what is world space and eye space in game development?

I'm reading a book about 3D stuff and OpenGL. The book often talks about world space and eye space. What exactly is the "world space?" Does the "eye space" mean the projection?
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3answers
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Font outline in OpenGL, FTGL

I'm using FTGL library to render fonts in my game, but I have completely no idea how to create an outline around text. Achieving a shadow could be easy, because I can simply do it like this: (pseudo ...
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3answers
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What is a better abstraction layer for D3D9 and OpenGL vertex data management?

My rendering code has always been OpenGL. I now need to support a platform that does not have OpenGL, so I have to add an abstraction layer that wraps OpenGL and Direct3D 9. I will support Direct3D 11 ...
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2answers
9k views

GLSL Shader - Change Hue/Saturation/Brightness

I'm trying to change the hue of an image using a GLSL fragment shader. I want to achieve something similar to Photoshop's Hue/Saturation Adjustment layer. In the following image you can see what I've ...
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2answers
612 views

What is the primary use of Vertex Buffer Objects?

From what I've read, it seems VBOs are purely for performance. I'm working on a very rudimentary learning project in lwjgl and I'm just trying to figure out what more advanced features of the library ...
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4answers
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Trapping mouse inside window in OpenGL with GLUT?

I perfectly understand that GLUT is limited and the following problem can't probably be solved with OpenGL/GLUT, but since I don't know exactly if it can or not, I better just ask. Maybe I'm doing ...
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2answers
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In OpenGL, how can I discover the depth range of a depth buffer?

I am doing a GL multi-pass rendering app for iOS. The first pass renders to a depth buffer texture. The second pass uses the values in the depth buffer to control the application of a fragment shader. ...
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2answers
786 views

What is the advantage of OpenGL's direct state access mechanism?

I've been reading about OpenGL 4.5 Direct State Access (DSA) at opengl.org and not sure if I'm getting it right. It seems to imply, that the old way is less efficient: glBind(something) glSetA(..) ...
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1answer
1k views

Sprite sheets with buffer objects and shaders

What is the "best" way to handle sprite sheets with shaders and buffers? In immediate mode it is easy to modify a sprite's texcoords when it is drawn, but I don't know how to do this with modern ...
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1answer
1k views

Taking advantage of multithreading between game loop and openGL

Talking in context of a game based on openGL renderer : Let's assume there are two threads : Updates the game logic and physics etc. for the in game objects Makes openGL draw calls for each game ...
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1answer
156 views

How can I profile the speed of my vertex and fragment shaders separately?

I'd like to know how I can check to see if either my vertex or my fragment shader is a bottleneck in my rendering pipeline. I've read about using glQueryCounter with the GL_TIMESTAMP target to get ...
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4answers
404 views

Why nearby triangles tend to disappear?

I've just enabled back face culling and I'm noticing a weird behavior: when all vertices of my triangle is outside the view and 2 of them is behind me (I think) the triangle disappears. So to see it, ...
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4answers
500 views

What types of effects or shaders would you teach in a rendering class? [closed]

I am looking for a list of topics that would be fun to learn and not too complicated to implement with a prototyping tool like FX Composer or Rendermonkey for an intermediate class of real-time ...
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1answer
1k views

How to efficiently render a large terrain mesh?

Recently I've been stuck on a problem thinking about the best way to generate a terrain into my game. In another projects I normally used heightmaps, so all the core-work was based on the engine used, ...
8
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1answer
413 views

OpenGL: Light at end of tunnel effect

Anyone knows any implementation of the "light at the end of tunnel" effect? where the outside is entirely bright and gradually becomes more visible? The reverse could also be true, where the inside ...
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3answers
736 views

I would like to know how an OpenGL driver will be implemented to learn opengl internals?

I'm learning OpenGL and really like to know how the interaction with the Graphics card will be. I feel understanding how it was implemented in the Graphics driver, will let me know complete internals ...
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4answers
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Geometric Transformations on the CPU vs GPU

I've noticed that many 3d programs normally do vector/matrix calculations as well as geometric transformations on the CPU. Has anyone found an advantage in moving these calculations into vertex ...
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1answer
907 views

Rendering 8 bit graphics

I have a strong programming background just not from game development. I only made some pong and snake in high school and I did some OpenGL in college. I want to make my own game engine. Nothing ...
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1answer
1k views

Getting OpenGL hardware acceleration with SDL on Linux

I'm trying to use SDL + OpenGL but I don't believe hardware acceleration is working because the framerate for around 18000 polys is about 24fps on a quad core machine but is a hopeless 1-2fps on an ...
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4answers
9k views

How to improve batching performance

I am developing a sprite based 2D game for mobile platform(s) and I'm using OpenGL (well, actually Irrlicht) to render graphics. First I implemented sprite rendering in a simple way: every game object ...
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2answers
451 views

stencil shadows - doom 3 engine - precision errors - shadow cracks - why?

I am testing the limits of the Doom 3 engine - in regards to maximum map size. I noticed some stencil shadow precision errors that become more pronounced when objects get further and further away ...
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1answer
12k views

How does gluLookAt work?

From my understanding, gluLookAt( eye_x, eye_y, eye_z, center_x, center_y, center_z, up_x, up_y, up_z ); is equivalent to: glRotatef(B, 0.0, 0.0, 1.0); ...
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2answers
2k views

How do I apply skeletal animation from a .x (Direct X) file?

Using the .x format to export a model from Blender, I can load a mesh, armature and animation. I have no problems generating the mesh and viewing models in game. Additionally, I have animations and ...
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votes
2answers
621 views

Does use of simple shaders improve performace/battery life?

I'm making OpenGL game for Android. Till now i've used only fixed function pipeline, but i'm rendering simple things. Fixed function pipeline includes a lot of stuff i don't need. So i'm thinking ...
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2answers
2k views

Frustum Culling with VBOs

I have terrain being rendered in my project using VBOs in OpenGL. I would like to apply some Frustum Culling but have no idea how to access each polygon as its drawn to check if it is in view. I think ...
8
votes
1answer
517 views

Creating a glitch effect similar to Watch Dogs

I'm currently working on a LibGDX game. When a user does something wrong, I would like all the graphics on the screen to jitter very similar to the glitch/distort effect seen in the game Watch Dogs ...
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2answers
246 views

How to avoid subpixel values in a resolution independent 2D game with orthographic projection?

I'm trying to do resolution independent rendering of moving sprites in a 2D game. My plan is work in a fixed coordinate system in my world (for example 960x540) and use orthographic projection to ...
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2answers
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How to deal with OpenGL and Fullscreen on OS X

I do most of my development on OS X and for my current game project this is my target environment. However when I play games I play on Windows. As a windows gamer I am used to Alt+Tab switching from ...
8
votes
1answer
831 views

2D Water top surface profile

I am trying to create the effect of the water surface thickness with a vertex-fragment shader. I am in a 3D game environment but It's a scroll view so a "2D" view. Here is a good tutorial of creating ...
8
votes
2answers
561 views

Need advice for 3D BSP based graphics engine

I have coded myself a OpenGL BSP viewer for an old game format. It is very similar to the Quake 3 file format. Because my interest is developing graphics engines, I want to be developing while looking ...
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5answers
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OpenGL vs OGRE : Which is the best for beginner? [closed]

I am interested in getting into game development and posses good C/C++ programming skills. I have tried OGRE before, and I am curious whether I should learn either OGRE or OpenGL as a starting point. ...
7
votes
2answers
291 views

2-components color model

RGB is the natural color model for OpenGL. But a lot of other color models exist. For example, CMY(K) for printers, YUV for JPEG, the little cousins YCbCr and YCoCg, HSL & HSV from the 70's, and ...
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5answers
2k views

Correct level of abstraction for a 3d rendering component?

I've seen lots of questions around this area but not this exact question so apologies if this is a duplicate. I'm making a small 3d game. Well to be honest, it's just a little hobby project and ...
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2answers
3k views

Using HTML for interface? [closed]

The game I've been working on uses opengl/sfml for graphics. I'm currently working on the interface and I've found determining all the proper offsets/positioning etc. to be a pain. To make it ...
7
votes
3answers
4k views

Draw contour around object in Opengl

I need to draw contour around 2d objects in 3d space. I tried drawing lines around object(+points to fill the gap), but due to line width, some part of it(~50%) was covering object. I tried to use ...
7
votes
1answer
2k views

Most efficient way to draw vertex with OpenGL

I am writing an OpenGL 3D game. There will be tons of triangles for terrain and objects in use. I am studying from the OpenGL official guide and the first presented method is to call a function ...
7
votes
1answer
680 views

How wise is this multithreading architecture?

I'm rewriting a game engine I wrote in an attempt to parallelize as much as possible. I'm considering making properties which may be accessed from multiple threads all use accessors which use boost ...
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votes
6answers
909 views

Does one need normals for a strictly 2d Game?

I'm starting to learn OpenGL by creating a pure 2D game. I have to decide on the format of the Vertices. Do I need a normal component? Or is this for a 2d component not needed? My gut feeling says I ...
7
votes
4answers
1k views

glsl demo suggestions?

In a lot of places I interviewed recently, I have been asked many a times if I have worked with shaders. Even though, I have read and understand the pipeline, the answer to that question has been no. ...
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votes
2answers
373 views

Must I worry about quad-based rendering in real world scenarios?

Most of the time in the first chapters of a random book about rasterization and rendering techniques, I find some phrases about a triangle-based rendering system and a quad-based one. I have never ...
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3answers
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What is the contents of the buffer *after* a call to glSwapBuffers()?

(SDL_GL_SwapBuffers() in particular) When you have drawn a scene, and you call swap-buffers, it is routine to then glClear() the scene before drawing anything; if you don't clear, what is the ...
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2answers
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How many OpenGL programs should I use to render multiple objects?

My scene has multiple objects in it. (Let's say 3 cubes, 1 cylinder, 8 spheres.) I assume I should create a vertex shader for each. How many programs should I have? Alternatives: One program per ...
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3answers
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How do I implement occluded lighting in a block-based 2D game?

I want to have 2D lighting that can be blocked by in-game objects. My game has a top-down view and all game objects are described by rectangles. Let's say I have a 10x10 world and I place a light at ...
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2answers
4k views

How do I load textures with SFML for OpenGL?

I'm looking at NeHe's texture mapping tutorial. It looks overly complicated for just loading a texture. Is there a way to load a texture in SFML and then use it in Open GL? I use SFML for my ...