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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How to reduce image size without pixelation?

I see lots of games with smooth edges characters and high res images, however when I try to reduce images to say 64x64 for my character I just get a pixelated mess. even if I start with a 64x64 canvas ...
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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, ...
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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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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, ...
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OpenGL ES 2.0 Point Sprites Size

I am trying to draw point sprites in OpenGL ES 2.0, but all my points end up with a size of 1 pixel...even when I set gl_PointSize to a high value in my vertex shader. How can I make my point sprites ...
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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 ...
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when to use vertex array and when to use vbo

i'm trying to learn about vertex array and vertex buffer object, but i don't understand the differences in term of: case-of-use (static geomerty like terrains, geometry that change every frame like ...
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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 ...
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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 ...
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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 ...
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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 ...
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How do I create good looking plasma explosion effects?

Is this just a billboard quad with a bloom shader?
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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 ...
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Modern shadow rendering techniques?

What is the state of the art in terms of shadow rendering? My target is OpenGL 3.2, using a deferred rendering pipeline, if that matters. It's been years since I looked into shadow rendering, and at ...
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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 ...
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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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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 ...
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335 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 ...
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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 ...
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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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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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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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OpenGL's matrix stack vs Hand multiplying

Which is more efficient using OpenGL's transformation stack or applying the transformations by hand. I've often heard that you should minimize the number of state transitions in your graphics ...
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Deferred shading - how to combine multiple lights?

I'm starting out with GLSL and I've implemented simple deferred shading that outputs G-buffer with positions, normals and albedo. I've also written a simple point light shader. Now I draw a sphere ...
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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 ...
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739 views

Mesh manipulation on GPU vs CPU

Just a bit curious - where do you perform mesh manipulations, on the CPU or in the shader? I've been doing everything on the CPU and a friend suggested moving things on to the GPU side. If you're ...
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differences between opengl 3 and opengl 4

I'm just getting started with game programming and I want to start learning opengl. I found a very great tutorial from scratch to get started with opengl 3 and I'm wondering if there is a big ...
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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?
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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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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 ...
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1answer
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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 ...
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1answer
635 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 ...
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How can I create a glitter effect?

I am trying to create a glittering effect for my realtime shader but I don't know how. Here is one example, and another example. What technique can I use to implement this?
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Handle many lights in a scene (with shaders)

I'm curious about how to handle many lights in a scene. Given a very big map in a role playing game, with dungeons (with lights in there) etc. I know about deferred lighting, but that only answers how ...
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In OpenGL, what is “zero state” rendering?

Recently at a job interview, I mentioned that I taught myself modern OpenGL and rendering with vertex buffer objects because my university only taught the fixed function pipeline with immediate mode ...
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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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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 ...
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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 ...
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1answer
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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 ...
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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 ...
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Sorting objects before rendering

I'm trying to implement a scene graph and in all the articles i've come across there is talk about object sorting. So you'd sort your objects by "material" for example. Now untill i sat down and ...
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2answers
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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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1answer
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How do I generate a 3D race track from a spline?

I want to generate a 3-dimensional race track around a spline that describes its shape. Here's an illustrative video. The track should be an endless tunnel that sweeps along a 3D spline, with some ...
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1answer
455 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, ...
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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 ...
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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 ...
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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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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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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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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 ...