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 ...

learn more… | top users | synonyms

1
vote
3answers
37 views

How to create a seamless cubemap noise texture?

I have, so far, been able to create the vertices and UV coords etc for a sphere that would be textured with a cube map. I have also successfully loaded a cube texture from file and applied it to my ...
2
votes
1answer
341 views

How do I build Assimp with MinGW?

How can I build Assimp with cMake and MinGW? I tried, but I don't get a functioning library... Details of my attempt: I am trying to build the Open Asset Import Library (Assimp) but I have been ...
0
votes
0answers
31 views

Is Phong shading supposed to be so camera-angle dependent?

I'm not sure if I have a bug in my code or not. It seems like it's a bug, or at least a major shortfall. Here's two images of the same model at slightly different angles (by moving the camera): As ...
0
votes
1answer
25 views

Loading Indices Collada File

I have been writing a COLLADA loader in c++ and I have run into a problem loading the indices for the mesh vertices whenever I try and find what indices correspond to the vertices and I try and draw ...
0
votes
1answer
165 views

How to compute matrix transform local/world on OpenGL

I'm developing an OpenGL program where each object / entity contains m_WorldPosition, m_WorldOrientation, m_WorldScale and m_WorldTransform (Vector3, Quaternion, Vector3 and Matrix4f). The problem is ...
4
votes
0answers
35 views

Tone mapping and eye adaptation - pale colors and darker image

I'm trying to implement tone mapping along with eye adaptation and HDR. Actually I implemented this already but I'm not satisfied with result and I think that I made something wrong. My final image ...
2
votes
0answers
17 views

Rectangular area light illuminance - colour banding

I'm currently working on an implementation of rectangular area lights but I am having some issues with the illuminance calculation, which gives me serious colour banding across the entire lit area. ...
1
vote
2answers
176 views

Tiled Rendering - Projection matrix

I'm trying to figure out how to perform tiled rendering of my 3d scene (OpenGL). The motivation is to cut the scene up into several textures, combining them into a single image for saving at a very ...
0
votes
0answers
31 views

Orthographic viewport zooming

I'm a bit new in opengl so please bear with me. I have a viewport window like this I have implemented zoom in/out features using the arrow keys. The problem is it zooms in and out with the whole ...
0
votes
1answer
34 views

Parsing Blender exported collada file in c++

Since I could not find any libraries that can help me parse collada files in my c++/opengl project, I decided to write my own. (I did find assimp, but binaries for Visual Studio 2013 were't available, ...
3
votes
1answer
78 views

FBX Importer - Vertex Color

I imported vertex positions, indices and normals successfully in OpenGL using fbx sdk, but I just can't figure out how to import vertex colors. I tried to fetch the pointer to array of colors trough ...
0
votes
1answer
136 views

Trying to implement Camera

I'm trying to implement a Camera class in order to walk and look on the world as follow: #ifndef _CAMERA_H_ #define _CAMERA_H_ #include <glm\glm.hpp> class Camera { public: Camera(); ...
2
votes
1answer
3k views

How to implement a basic arcball camera in OpenGL with GLM

I only just started learning OpenGL and even things like vector maths etc a couple of days ago, so I am having a bit of trouble figuring out exactly what to do to implement an arcball camera system. ...
0
votes
0answers
17 views

Simple OpenGL ES Cube [on hold]

I have been trying to render a very simple cube using OpenGL ES. The code seems to be fine, but I am not experienced with OpenGL ES. I have been trying to learn it. It would be good if anybody could ...
-2
votes
0answers
71 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 ...
2
votes
1answer
66 views

Blending vs Texture Sampling

I don't think this question has been asked before as I couldn't find any information about this on the internet. Lets say I want to blend two textures together: A texture containing the result of ...
1
vote
0answers
27 views

Confused About My Code Suggesting The Normal Matrix Is Equivalent To The ModelView Matrix

I'm learning environment mapping in OpenGL by following this page. In his vertex shader, the author calculates the vertex normal in eye space with the following code: nEye = vec3(viewMatrix * ...
0
votes
1answer
25 views

LWJGL 3, VAO and Shader not rendering [on hold]

X-post from Stack Overflow because its receiving little attention. I am using LWJGL 3 and Shaders with VAO's. My current implementation does not draw the VAO when using the shaders. However the VAO ...
0
votes
1answer
24 views

Java OpenGL Perspective matrix not working

I'm trying to render a simple triangle with OpenGL in Java using LWJGL3. Everything is working great, but the projection matrix (perspective) is not working. In C++ I just used to apply the ...
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
95 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
95 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
65 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
24 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
100 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
41 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
63 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
264 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 ...
1
vote
2answers
189 views

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

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
50 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
45 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
61 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
71 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
42 views

WebGL Multiplayer Game - Direction Needed (Shaders) [closed]

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
82 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
74 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
28 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
72 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
93 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
27 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? [closed]

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 ...
11
votes
3answers
259 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
41 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
259 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 ...