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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3answers
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Writing Game Engine from scratch with OpenGL [closed]

I want to start writing my game engine from scratch for learning purpose, what is the prerequisites and how to do that, what programming languages and things you recommend me? Also if you have good ...
12
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1answer
6k views

How can I tell how much video card memory I'm using?

I want to programmatically determine at runtime how much video card memory is being used by my program. Specifically I'm wondering about how to do it on a Windows machine using OpenGL, but am ...
12
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2answers
594 views

How does Halo draw projectiles?

I am trying to draw projectiles and doing billboarding. A projectile consists of a bill-boarded "particle" and a "tracer". When I billboard a projectile, it cannot be seen when the player's viewing ...
12
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3answers
2k views

Rotate object around fixed axis

I am trying to let the user of my app rotate a 3D object drawn in the center of the screen by dragging their finger on screen. A horizontal movement on screen means rotation around a fixed Y axis, and ...
11
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2answers
17k views

How many textures can usually I bind at once?

I'm developing a game engine, and it's only going to work on modern (Shader model 4+) hardware. I figure that, by the time I'm done with it, that won't be such an unreasonable requirement. My ...
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8answers
20k views

Getting Started with 2d Game Dev (C++): DirectX or OpenGL? [closed]

So, i'm a student looking to get my foot in the door of game development and im looking to do something 2D, maybe a tetris/space invaders/something-with-a-little-mouse-interaction clone. I pointed ...
11
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2answers
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Am I allowed to make my Minecraft clone open source?

I'm developing in my spare time a game like Minecraft. In fact, it isn't "like Minecraft", because I'm trying to make it a close as possible copy of it (meant as exercise for myself at the age of 16 ...
11
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3answers
2k views

Go pure OpenGL or GLSL? [closed]

I got interested in studying graphic programming so the obvious entry point was to learn OpenGL. But gathering scattered information around forums and sites, it seems that a pure OpenGL implementation ...
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2answers
3k views

How to make natural looking voxel

I'm developing a voxel game, but I think I use the wrong technique. I currently use flat tiles, to make blocks, and I think theres a better and more efficient way. I have seen a voxel game, which ...
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4answers
6k views

Why the clip space in OpenGL has 4 dimensions?

I will use this as a generic reference, but the more i browser online docs and books, the less i understand about this. const float vertexPositions[] = { 0.75f, 0.75f, 0.0f, 1.0f, 0.75f, -0....
11
votes
4answers
26k views

How can I orbit a camera about it's target point?

I'm drawing a scene where the camera freely moves about the universe. The camera class keeps track of the view (or look at) point, the position of the camera, and the up vector. These vectors/points ...
11
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5answers
882 views

API agnostic bridges (ie. OpenGL/D3D/Whatever). Do you use them, how you make them. Pro's and Con's

You are making a 3d engine. You want best of multiplatform worlds. Suddenly you realize that if you want to use Direct3D on Windows machines and OpenGL on OSX/Linux, you'll have to sacrifice supported ...
11
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1answer
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OpenGL: Resizing Display and glOrtho/glViewport

I have researched this question from several sources and have yet to find a firm answer saying that "yes that is correct thinking" or "no, here is how it's done." I am trying to ensure resolution ...
11
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2answers
4k views

What should I worry about when changing OpenGL origin to upper left of screen?

For self education, I'm writing a 2D platformer engine in C++ using SDL / OpenGL. I initially began with pure SDL using the tutorials on sdltutorials.com and lazyfoo.net, but I'm now using SDL to ...
11
votes
1answer
630 views

How to achieve light that changes color mid-way?

I thought of creating light sources, and some colored windows. Now, the windows are semi-transparent. How could I make it so that when the light (say, pure white) hits the glass and continues through ...
11
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1answer
4k views

How does UVW texture mapping work?

I'm trying to understand the mathematical theory behind UVW mapping. Can anyone explain me how UVW mapping works? Or at least provide me a pointer?
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2answers
9k views

Most common 3D model format for opengl

I'm a novice that is starting to play with OpenGL ES on Android devices. To practice OpenGL I wanted to create a small game engine and so I was wondering what the best 3D model file format would be. ...
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3answers
11k views

Trying to understand light on Opengl, how to simulate a realistic sun light?

I don't know if I'm doing something wrong or missing anything but I want to simulate sun light, like in a sunny day. When the object is facing the directional light, it's well lit and there's no ...
11
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2answers
3k views

Large vertex buffer vs multiple draw calls

I'm just getting started with OpenGL, and I'm attempting to use it to create a 2D game. In this game, I have a hexagonal grid made up of a very large variety of differently-colored hexagons. As a ...
11
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3answers
5k views

What is the difference between OpenGL 1.x and 2.x?

Is there a good tutorial that shows the difference between OpenGL 1.* and 2.*? It would be very helpful to know which functions I should not be calling (like glBegin(), I assume).
11
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2answers
7k views

How do I use depth testing and texture transparency together in my 2.5D world?

Note: I've already found an answer (which I will post after this question) - I was just wondering if I was doing it right, or if there is a better way. I'm making a "2.5D" isometric game using OpenGL ...
11
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1answer
151 views

OpenGL binding and relations among entities

This is mostly a documentation question. I hope this is the proper place to ask and not, for example, programmers or stackoverflow. I did not read the OpenGL specification, but from books (Red Book) ...
11
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1answer
434 views

Rendering only a part of the screen in high detail

If graphics are rendered for a large viewing angle (e.g. a very large TV or a VR headset), the viewer can't actually focus on the entire image, just a part of it. (Actually, this is the case for ...
11
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2answers
3k views

Deferred tiled shading, tile frusta calculation in OpenGL

I'm trying to do deferred tiled shading in OpenGL using the compute shader but I have hit a snag when trying to create the frustum for each tile. I'm using AMD's Forward+ demo (written in D3D) as a ...
11
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1answer
3k views

GLSL, all in one or many shader programs?

I am doing some 3D demos using OpenGL and I noticed that GLSL is somewhat "limited" (or is it just me?). Anyway I have many different types of materials. Some materials have ambient and diffuse color, ...
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5answers
14k views

What alternatives to GLUT exist?

I am trying to learn OpenGL, and I just found out that GLUT is obsolete. I already know SDL, and it seems it is a good alternative. Should I use SDL to develop games with OpenGL, or are there any ...
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3answers
6k views

How can I bend an object in OpenGL?

Is there a way one could bend an object, like a cylinder or a plane using OpenGL? I'm an OpenGL beginner (I'm using OpenGL ES 2.0, if that matters, although I suspect, math matters most in this case, ...
10
votes
3answers
2k views

Missing features from WebGL and OpenGL ES

I've started using WebGL and am pleased with how easy it is to leverage my OpenGL (and by extension OpenGL ES) experience. However, my understanding is as follows: OpenGL ES is a subset of OpenGL ...
10
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2answers
5k views

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. ...
10
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1answer
2k views

Engine Rendering pipeline : Making shaders generic

I am trying to make a 2D game engine using OpenGL ES 2.0 (iOS for now). I've written Application layer in Objective C and a separate self contained RendererGLES20 in C++. No GL specific call is made ...
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2answers
2k views

Rendering characters, with cut off limbs (Blender models in Java/OpenGL)

What aspects should I take into consideration for creating character animation and rendering classes if I want to be able to have detachable limbs? I've developed a detailed body system that can have ...
10
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1answer
4k views

How can I create a “night sky” effect in OpenGL?

I am creating a game using OpenGL and I want to render the effect of a night sky with a few stars in it. I want to have a shiny black effect in the sky so that it looks good. Could some one help in ...
10
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1answer
2k views

Should I give each character its own VBO or should I batch them into a single VBO?

I'm making a 3D first person game. Should I give each character its own VBO or should I batch all characters into a single VBO? What are the pros/cons?
10
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1answer
1k views

How do I create good looking plasma explosion effects?

Is this just a billboard quad with a bloom shader?
10
votes
1answer
716 views

Why is it Important to have render targets with the same bit size?

I am currently thinking of what type of GBuffer I'll need for deferred shading, hence I tried also to document myself online about the most common ones and their format. Most of the GBuffer that I'...
10
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4answers
8k views

Object-Oriented OpenGL

I have been using OpenGL for a while and have read a large number of tutorials. Aside from the fact that a lot of them still use the fixed pipeline, they usually throw all the initialisation, state ...
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3answers
3k views

Lighting in a Minecraftian World

Minecraft is a game that is largely based on a heightmap and uses that heigtmap information to flood the world with light. From my understanding the highest point in the heightmap is the end of the ...
10
votes
2answers
2k views

Are there still advantages to using gl_quads?

OK, I understand that gl_quads are deprecated, and thus we're not 'supposed' to use them anymore. I also understand that a modern PC when running a game using gl_quads is actually drawing two ...
10
votes
1answer
13k views

OpenGL/GLSL: Render to cube map?

I'm trying to figure out how to render my scene to a cube map. I've been stuck on this for a bit and figured I would ask you guys for some help. I'm new to OpenGL and this is the first time I'm using ...
10
votes
2answers
4k views

Efficient skeletal animation

I am looking at adopting a skeletal animation format (as prompted here) for an RTS game. The individual representation of each model on-screen will be small but there will be lots of them! In ...
10
votes
5answers
5k views

Skybox texture artifact on edge

I have strange problem with drawing skybox texture on Mac. On iPhone everything is going fine. I have tried to change near and far planes value with no success. It is a skybox of six textures, and ...
10
votes
1answer
5k views

How to use multi-thread OpenGL application to update VBO and use it at the same time?

I have simple application. It has two threads. Each thread has it's own rendering context, but they share one VBO (this is working, I tested it). Now what I want: One thread is rendering some data ...
10
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1answer
577 views

Deforming surfaces

I try to accomplish an deforming physic behaviour for levelsurfaces, but don't get an idea how to start with the implemenation so far. Regardless of the shape from the surface (planes, cubes, spheres…)...
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3answers
5k views

Animation in OpenGL using 3D Models

I have created a model in Blender. Now i want to read that 3D model in my c++ program. I figured that a model can be exported to various file formats e.g. .obj, .3ds or COLLADA and then can be read in ...
10
votes
1answer
184 views

Draw the middle half of a sphere programmatically

I'm trying to create the middle half of a sphere. Basically to create a sphere, stack numbers and slice numbers are given, and there are two variables phi (for slices) and theta (for stacks) ...
9
votes
5answers
4k views

Is GLUT obsolete?

A question was asked about good, up-to date OpenGL resources, one of the answers was a link to a tutorial about modern OpenGL programming. The tutorial in question uses GLUT and GLEW, but I have read ...
9
votes
3answers
4k views

Order independent transparency in particle system

I'm writing a particle system and would like to find a trick to achieve proper alpha blending without sorting particles because: Each particle is a point sprite in a single mesh and I can't use ...
9
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6answers
9k views

AAA Games and OpenGL?

What modern AAA games on the top of the market used OpenGL? If applicable, what engine did they use?
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2answers
4k views

How do OpenGL's texelFetch and texture differ?

I understand the main differences between texelFetch and texture, but have some questions about the details: Does texelFetch involve a performance penalty? Such as not using a cache or such? Are ...
9
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2answers
5k views

OpenGL: Is it possible to use VAO's without specifying a VBO

On all the tutorials I can find about VAO's (Vertex Array Objects), they show on how to use them by configuring vertex attributes and binding a VBO (Vertex Buffer Object). But I want to create a VAO ...