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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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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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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341 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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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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381 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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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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837 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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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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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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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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OpenGL get the outline of multiple overlapping objects

I just had an idea for my on-going-game made with opengl in c++: I'd like to have a big outline (5-6 pixel) on multiple overlapping object when the player win something. I thought the best way is to ...
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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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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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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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2answers
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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 ...
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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 ...
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655 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 ...
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527 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. ...
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What is the purpose of glScissor?

I know that it is more efficient than stencil test, but am I right assuming that the same functionality could be achieved using projection transformations with viewport?
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7answers
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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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2answers
261 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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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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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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Using HTML for interface?

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 ...
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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 ...
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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 ...
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604 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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6answers
891 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 ...
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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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2answers
332 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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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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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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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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How do I change a sprite's color?

In my rhythm game, I have a note object which can be of a different color depending on the note chart. I could use a sprite sheet with all the different color variations I use, but I would prefer to ...
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5answers
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Is there a way to blur objects in a 2d game with OpenGL without using shaders?

Is there a nice way in OpenGL to blur objects without using shaders? Currently, I'm accomplishing blur by rendering the object slightly up, down, left, right, and the four diagonals from its original ...
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1answer
746 views

Most efficient way to draw large number of the same objects, but with different transforms

I'd like to draw a large number (multiple thousands) of simple meshes (each maybe... a maximum of 50 triangles, but even that is a very large upper bound), all of which are exactly the same. As a ...
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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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1answer
517 views

Best practices with Vertices in Open GL

What is the best practice in regards to storing vertex data in Open GL? I.e: struct VertexColored { public: GLfloat position[]; GLfloat normal[]; byte colours[]; } ...
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Why should I not use glTools/glut when developing complete applications?

I've started learning how to use OpenGL a while back, using the OpenGL SuperBible, Fifth Edition, and I've had people arguing about the fact that the book doesn't really teach how to use OpenGL but ...
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2answers
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OpenGL 2 and back vs 3 and forward: What are the key differences for 2D graphics?

OpenGL contexts before and after OpenGL 3.0 are rather different. So far I've really only worked with buffers on either side anyway, I do know the most notable difference is lack of Immediate Mode. ...
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3answers
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OpenGL - Stack overflow if I do, Stack underflow if I don't!

I'm in a multimedia class in college, and we're "learning" OpenGL as part of the class. I'm trying to figure out how the OpenGL camera vs. modelview works, and so I found this example. I'm trying to ...
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2answers
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Fastest way to draw small particles in opengl?

Quick question : Which is the fastest method to render a large array of 4x4/8x8 particles in opengl ? Currently i spend 2triangles for each one but i think that its slow so i would really like to know ...
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3answers
2k views

Optimizing Octree Rendering

Say I have an octree and at a certain level I store VBOs in that octree. I know the dimensions of of the nodes that own the vbo so I can do basic frustum culling. That works nicely because everything ...
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1answer
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Interleaving Arrays in OpenGL

In my pursuit to write code that matches todays OpenGL standards I have found that I am completely clueless about interleaving arrays. I've tried and debugged just about everywhere I can think of but ...
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1answer
748 views

Do I really have to write my own optimized model format?

So I'm a brand new noob to the world of game dev and I'm starting off by trying to write my own game using C++ and openGL. I'm getting into loading models etc and while searching around for "the best ...
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What causes some computers to have no or slow OpenGL, and how to fix it?

I am using Java with JOGL to create OpenGL enhanced 2D graphics. The graphics operations I use are nothing fancy, and should be supported by almost any recent graphics card. For example, my game ...
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Which c/c++ model animation library for OpenGL [closed]

I'm fairly new to game development, played around with xna before and just learning OpenGL & c now and I'm interested to know which c/c++ based model animation libraries are out there and which ...
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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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SDL2 with OpenGL — weird results, what's wrong?

I'm porting an app to iOS, and therefore need to upgrade it to SDL2 from SDL1.2 (so far I'm testing it as an on OS X desktop app only). However, when running the code with SDL2, I'm getting weird ...