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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14
votes
6answers
4k views

What is the purpose of the canonical view volume?

I'm currently learning OpenGL and haven't been able to find an answer to this question. After the projection matrix is applied to the view space, the view space is "normalized" so that all the points ...
-3
votes
1answer
79 views

Licensing and commercial game development [on hold]

I am thinking about developing my game and have a few questions. I am going to use these softwares and libraries : OpenGL, Visual Studio Express, GLFW. I have publishing and selling my game in plans. ...
1
vote
1answer
92 views

SDL & OpenGL - Artifacts when multisampling

Im trying to render a model with anialiasing using OpenGL and SDL, but when I do I get strange artifacts. When I render with antialiasing disabled everything looks fine. When antialiasing is ...
0
votes
1answer
61 views

OpenGL streaming from multiple windows

I am using GLUT library for my research/game. In my game I have 25 windows created using glutCreateWindow(title), and each of them have their own display callback registered using ...
0
votes
0answers
23 views

How to convert Screen-space translation into World-space translation

private void Translate(SceneMouseMoveEventArgs args) { var camera = args.Camera; origin_screenspace = camera.UnProject(_position).Xy; cursor_screenspace = new ...
3
votes
2answers
87 views

Can I use the HD Graphics 3000's quad list primitive type via D3D?

I was studying some technical documentation on the Intel HD Graphics 3000 GPU, which I'm using as a lower-end reference for my 2D game engine. I noticed the hardware supports a nice "Quad List" ...
3
votes
1answer
36 views

OpenGL Framebuffer Object issue

I am struggling with implementing a proper Framebuffer Object . glCheckFramebufferStatus is returning me: GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT (36054). What am i missing? GLuint fbo, rboColor, ...
3
votes
1answer
61 views

Why does glBindVertexArray sometimes fail (but mostly not)?

Quick outline: Test program that loads and displays big (3k x 4k) 16bit gray scale images (ca. 32MB). Using modern OpenGL (eg. 3.3 or so) with shaders VBOs VAOs etc. Running on Windows with OpenTK ...
3
votes
1answer
258 views

Using textureGrad for anisotropic integration approximation

I'm trying to develop a real time rendering method using real time acquired envmap (cubemap) for lightning. This implies that my envmap can change as often as every frame and I therefore cannot use ...
-2
votes
0answers
64 views

wrong position triangle draw when port code from opengl v330 to v210 [on hold]

im try learning modern open gl tutorial which is use open gl 3.3. then try applying VAO , VBO and EBO using texture data also. the triangle draws correctly in center. then try apply this using open ...
1
vote
2answers
188 views

Application of classes with critical non-static fields in LWJGL [on hold]

I'm going to be as specific about this question as I can. Ultimately, how is it that I apply a class that uses non-static fields in LWJGL? More specifically, I know that OpenGL is quite nearly more a ...
0
votes
1answer
47 views

What's the correct way to move 2d sprites in opengl 2.1?

I'm getting into Opengl 2.1 and wanted to know how can I move 2d sprites. I already created my vbo and ibo, and the vertex data is already there. But, how can I move a sprite once it's already drawn? ...
0
votes
0answers
41 views

Trouble with Raycast Selection using OpenGL

I am currently having trouble with a custom model editor in which I want to implement model selection (eventually featuring face selection to have something like "click-and-drag" to extend the cubes). ...
0
votes
1answer
40 views

GL_SPOT_CUTOFF not working properly

I'm new to OpenGL. I'm studying OpenGL 2.1 and I'm trying to make a little program to test the GL_SPOT_CUTOFF property, but when I set a value between 0.0-90.0, the light doesn't work and everything ...
3
votes
1answer
245 views

How do I use unpackHalf2x16?

I'm trying to use (un)packHalf2x16, without success so far. I'm drawing with: glVertexAttribIPointer(0, 2, GL_UNSIGNED_INT, 0, 0); glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vbo); ...
2
votes
1answer
58 views

Why does my simple OpenGL shadow map fail?

I want to render a simple shadow map for grass, where closer looks brighter and further looks darker, from the view of the light point. I can't get it to work. Here is the relevant code: //setting ...
1
vote
1answer
70 views

opengl : Running at least 25 windows with different Draw callback

I need to run at least 25 windows concurrently with each window rendering a different game state. I am storing all the 25 game states in the array of type GameState allGameStates[25]. For each of the ...
0
votes
0answers
41 views

WebGL Multiplayer Game - Direction Needed (Shaders) [on hold]

I've started looking into making a multiplayer game for web browsers. I started with a book "WebGL Up and Running" and it has lead me to be more curious about more detailed aspects of OpenGL. In ...
1
vote
1answer
77 views

OpenGL VBO and VAO Confusion

I would like to present here my Question about VBOs and VAOs. Basically from what i understand you can have different VAOs each of which can contain up to several VBOs , and by binding to the VAO's ID ...
2
votes
2answers
2k views

LWJGL multiple keyboard/mouse input checks

As in many game libraries such as LWJGL, you can check mouse/keyboard events with Mouse.isButtonDown or Keyboard.IsKeyDown. I want to check for button/key presses, not if it's currently pressed down ...
0
votes
2answers
72 views

node-webkit and OpenGL 4

Is there any way to get OpenGL 4 to work within a node-webkit app? It would have to be OpenGL 4 and since it's running on a desktop app I would think there must be a way to get it to work. I can't ...
1
vote
0answers
24 views

OpenGL enabled Java game not detected by Fraps

Recently I found out that I could enable OpenGL hardware acceleration in my java game with the line System.setProperty("sun.java2d.opengl", "True"); Initial tests showed a big boost in performance. ...
0
votes
2answers
67 views

Passing array to uniform in glsl error

Here is my attemps to pass array to uniform array: struct Vector{ float x,y,z; } float threshold[2] = { 0.5, 0.25 }; Vector *kernel = new Vector[_kernel_size]; // _kernel_size==16 // fill kernel ...
1
vote
1answer
105 views

Problems with texture orientation in space

I am currently drawing texture in 3D space and have some problems with it's orientation. I'd like me textures always to be oriented with front face to user. My desirable result looks like ...
1
vote
1answer
88 views

OpenGL: Draw an arrow

I'd like to know how to draw an arrow to represent a vector position, length and direction. The issue is that I can't quite find an easy way to know the location and rotation of the triangle ...
0
votes
0answers
26 views

Problem with glTranslate

I'm making a scroller learning from thebennybox tutorials. In his way of scrolling he does this each loop. public void render() { // glPushMatrix(); { // draw to center ...
1
vote
1answer
50 views

How are CSS and WebGL coordinates related? [on hold]

I'd like to build a simple framework which rendering combines web page DOM elements with WebGL, such that they're manipulable in the same coordinate space. How does the plain CSS coordinate system ...
10
votes
3answers
247 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 ...
1
vote
1answer
39 views

OpenGL why point's size stay the same while zooming/unzooming

i'm currently working on a game engine for a college's project. While implementing some debug tools I came across a little problem. When i'm drawing point on the ModelView Matrix the point's thickness ...
0
votes
1answer
36 views

Rotate heading relative to agent's local space

I'm having a little trouble translating a point in my game's world space to an object's local space. I have a cannon in my game with a normalized heading vector that's always supposed to point in the ...
5
votes
2answers
258 views

How does glRotate affect the axes of the global coordinate system?

I am currently playing around with 3D transformations applied on a 2D context in LWJGL, to later be implemented in my game. So I managed to set up LWJGL well enough (scaling, translating, scaling and ...
0
votes
0answers
13 views

Stack matrix affecting shooting mechanics

I attempted to make a scroller game using parallax scrolling in LWJGL. Everything is fine but I'm having trouble with the matrix stack and the bullets. So basically when I shoot the bullet it moves ...
0
votes
1answer
52 views

How can I split up a large model into an octree codewise?

For collision detection, I am attempting to split up a large model into an octree. If we take this black thing thing to be the ship (104,000 vertices): Then I would like to split up the faces I ...
4
votes
1answer
169 views

How can I efficiently represent territories and their borders on a map like if it was a Risk board game?

I am exploring the idea of programming a territory control based RTS. These territories would be in 3D and I would like their colors to change when captured to represent the faction's color. I would ...
2
votes
0answers
65 views

Does anyone know what technique was used in Minecraft to create shadows? [closed]

Specifically I want to know the technique used to render shadows under animals and players. I would like to create shadows like that for my own block game but I don't even know what to google. Any ...
0
votes
2answers
1k views

Do rendered-to-textures need to be bound when being drawn to?

In OpenGL, if I'm rendering to a texture using a framebuffer, do I have to have that texture bound while I'm rendering to it? In code: glBindTexture(...); glTexImage2D(...); glBindFramebuffer(...); ...
2
votes
0answers
44 views

How to generate a RGB * a texture for a glow effect in GLSL?

I would like to create a glow effect in GLSL, there is a tutorial that explains how we multiply RGB * a : I have some questions : is it an operation that is in a fragment shader, where RGBa is ...
0
votes
0answers
32 views

How to build cubes with rounded edges [duplicate]

I am building cubes with a subdivision method (3 levels per face) Is there a method to round the corners of the edge? I want to warp my cube to a sphere with a animation. I know, that I can normalize ...
2
votes
0answers
46 views

OpenGL Planet Generation - Simple Matrix Issue (Planet “Spins” With Mouse)

I originally asked this question on StackOverflow & was directed here by a commenter. Im currently working on a OpenGL planet rendering. I'm using the Tessellation pipeline. So far things are ...
2
votes
2answers
70 views

Translating an object in the rotation direction

I am creating a graphical scene with OpenGL and SDL, and I'm running into a problem in regards to translating an object in its rotation direction. Each of the graphical objects in the scene has a ...
0
votes
2answers
99 views

OpenGl indices array

I have a class terrain which create a grid of Quads. I do it like this for(int z=0; z<_length;z++){ for(int x=0; x<_width;x++){ ...
2
votes
1answer
54 views

How to assign texture to shader?

In OpenGL, most shader uniform variables are easy, a float or a vec3 or whatever is associated with a shader program. But samplers are different, we associate a texture unit to the shader program, and ...
0
votes
0answers
55 views

Frustum Culling is incorrect

I have checked the other posts on here, but haven't found a suitable answer. I'm trying to implement frustum culling using the Gribb-Hartmann technique, but am running into a strange issue where ...
0
votes
1answer
81 views

Java LWJGL - How can I click to interact with objects?

I want to be able to click on a monster to walk to him and start attacking him. The part that doesnt make sense to me is the conversion between the mouse position, and the actual terrain position. ...
0
votes
1answer
27 views

Flipped model has wrong triangle order

I have list of models and transform matrix for each of them. Some of models are flipped along X or Y or Z axis. This meshes will be rendered wrong, back face is rendered instead of front. I tried to ...
0
votes
3answers
175 views

Combine flat and smooth shading with a single model geometry

I need to be able to switch between smooth and flat shading interactively. Is there a way to do this efficiently with a single geometry? For example, smooth shading does not require duplicate ...
1
vote
1answer
173 views

What is the correct multiplication order for a 2D matrix?

I'm currently trying to create a camera and entity/model matrix for my 2D game similar to that of Unity3D. I've already tried to find answers to this question on stackoverflow/gamedev but i couldn't ...
0
votes
0answers
35 views

Modern OpenGL, rendering multiple obj objects not working

I am currently working on a 3D Game Engine that loads a level from an OBJ file and renders it with OpenGL. My problem is related to understanding how to render each object individually when i have ...
1
vote
0answers
24 views

postprocessing shader destroying viewport on linux?

Basically I implemented gamma correction into a q3 based game to get rid of the annoying SetDeviceGammaRamp. On windows and macosx everything works fine, but on linux it draws garbage. It looks like ...
1
vote
2answers
316 views

Calculating shadowmap coordinates for cubemap in shading pass?

I'm trying to implement shadow mapping with cube maps. I believe I've done the first stage by filling the cube map, but for the final shading pass I am unsure how to exactly calculate the cubemap ...