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

0
votes
0answers
42 views

LWJGL OpenGL Spotlight half-showing

Problem: Only half of the light is showing. Lighting Inilization code: glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glEnable(GL_DEPTH_TEST); glEnable(GL_NORMALIZE); ...
36
votes
1answer
6k views

Why are all OpenGL function calls prefixed with “q” in the Doom 3 source code?

Why is every OpenGL call prefixed with a "q" in the Doom 3 source code? Are they custom functions or a different library, and if so, why use that over OpenGL? Any Google search comes up with the Qt ...
0
votes
0answers
36 views

How can I render several rectangles efficiently? (LWJGL)

I'm working with OpenGL3+ rendering and I am coming from OpenGL1.5. In GL1.5 I had rendered things like this: public class GraphicsDead { int vboVertexHandle; int vboColorHandle; public ...
1
vote
1answer
62 views

How can I manipulate a single pixel with LWJGL?

This is a very simple question. Is there a way to manipulate a single pixel? Here's an example of what I want in pseudo-code: while(gameIsOn) { renderAllObjects(); setPixel(x,y,r,g,b); } ...
0
votes
1answer
42 views

Using of opengl buffers

Newbie question, and sorry for my English. Suppose that we create a lot of GL_ARRAY_BUFFER buffers, fill them with some data. But only few of them we link with shader variables. During glDraw..., what ...
0
votes
1answer
38 views

LWJGL Lighting advice / fix

Problem: The spotlight I've set up with OpenGL won't light up anything behind it, no matter what values I set for GL_SPOT_DIRECTION float[] LightDir = new float[]{0,0,-1,0}; float[] ...
2
votes
1answer
320 views

Do I need to install any libraries or SDKs to use OpenGL?

I am wondering if I have to install libraries for openGL programming or if I can already use header files from the core library. I am asking this because I went to the SDK and there is no Core library ...
0
votes
2answers
76 views

Move towards view direction opengl?

I'm trying to get the basics of 3d with opengl 2.0(I know, I know, it's deprecated etc, etc. It's just for the sake of prototyping). I'm trying to get a cube on the screen which you can move around. I ...
0
votes
2answers
66 views

Is Global location using OpenGL bound by the shader?

I have recently started writing a game engine in C++ with OpenGL and using some tutorials online. So far from what I have seen, shaders are the way to manipulate an object's position in worldspace. Is ...
0
votes
1answer
80 views

glDrawElements and Texture Coordinate

I just move on from Immediate Mode and try Vertex Array method using glDrawElements and I got the texture is mess. How to draw the texture correctly? This is a piece of my render code ...
1
vote
0answers
74 views

Normal Mapping a Cubemap

I posted a question on Stackoverflow and it was suggested that it would be better asked here. I have a sphere. It was created via the icosphere method outlined here: ...
3
votes
2answers
560 views

How do I use graphics APIs to select the proper display device among multiple attached to a PC?

I have an LCD monitor display and Oculus Rift attached to my PC. I have an Nvidia 820M dedicated GPU. How does the GPU know to which display device it has to render (or to send rendered information)? ...
0
votes
1answer
92 views

Deferred Rendering with SFML

I've been looking to implement a deferred rendering system in SFML. I've read the tutorials on OGLdev for it, and I was wondering how to draw a scene built in SFML (sprites, text, etc) to the ...
0
votes
2answers
95 views

convert deprecated opengl function to modern opengl (3.3) [closed]

i need help to convert the render function of IQM model (void renderiqm()) to modern OpenGL (without the deprecated functions like enableClientState(), etc). The code of renderiqm() function is here: ...
1
vote
2answers
91 views

Is it possible to run GLFW eventhough my graphic card(Nvidia) supports Direct3d API? [closed]

I have Nvidia 820M GPU installed in my windows 7 machine. In nvidia control panel it is showing it supports Direct3d API version 11. Am I able to run OpenGL applications(using GLUT,GLFW) on my machine ...
4
votes
2answers
146 views

Best way of writing pixel manipuliting-intensive applications with OpenGL/Direct3D

Recently I have been making little experiments with engines similar to old Wolfenstein 3D, Doom and Build, engines where the 3D rendering is entirely done in software and therefore you need full ...
1
vote
0answers
102 views

OpenGL Texture Loading

I've been using OpenGL for a bit so I have a general idea of what I'm doing. Recently, I've been working on a framework to let me test stuff more easily. As part of the framework, I split up loading ...
0
votes
0answers
66 views

Camera rotation destroy scene objects orientation

I fight with that for some time and searching internet but I don't have any answer for my problem. In few words i want to have orbiting camera on screen and objects which I want also rotate ...
0
votes
0answers
60 views

OpenGL camera scrolling too fast

I'm using the code from this tutorial but in Java and LWJGL. The problem is I want the player to click and drag around the world with the mouse. I tried adding the mouse dx (velocity) to the camera ...
0
votes
0answers
60 views

Compiling a CUDA and OpenGL interop code in linux

I am trying to compile a CUDA code in which I am using interoperability with OpenGL to display a simple triangle. I am using a VBO for OpenGL rendering and I am registering this object with CUDA using ...
0
votes
2answers
90 views

Fragment shader compiling in webGL but not in OpenGL

I am programming in Haxe (language compiling to multiple platforms) and I have written some shaders. My fragment shader runs fine in html5, but when I try to compile for native (OS X and/or Neko, a ...
0
votes
1answer
49 views

glRotatef not rotating simple 2D triangle

I am new to OpenGL and am learning it for the purpose of some simulation that I am doing as part of my research work. I have been following the tutorials given at ...
1
vote
1answer
67 views

Can you trilinear sample a non volume texture?

Let's say that i have a regular 2d texture (not a volume texture). Is it possible to do trilinear texture sampling of that texture even though it isn't a volume texture in opengl or directx? ...
1
vote
1answer
121 views

Shadow mapping bone animated model

I am trying to get shadowmapping right for my animated models. It works perfectly for static meshes but the animated models are just wiggeling a bit here's the vertex shader for rendering to the ...
2
votes
2answers
185 views

Lasers in 3D space game

I am creating this little 3d space shooter and am somewhat unsure on how to implement the laser beams. I'm thinking about something along Star Wars and the like where mostly you shoot rather short ...
0
votes
1answer
49 views

useful way for coloring 3ds object in opengl

I have been working in making plane in blender and it has many materials over than 90 , and now I need it in an opengl project with c++ , but as you know if I but the 3ds file the plane color is ...
0
votes
0answers
37 views

Adding a 2D transformation matrix to GLSL

I'm having trouble understanding the matrices I need to render an object in OpenGL. I've been using a matrix to make up for the translation and scaling from the camera in my game but I didn't have a ...
8
votes
3answers
306 views

Using full resolution of depth buffer for 2D rendering

I'm working on a front-to-back renderer for a 2D engine using an orthographic projection. I want to use the depth buffer to avoid overdraw. I have a 16-bit depth buffer, a camera at Z=100 looking at ...
1
vote
0answers
39 views

Find camera coordinate of vanishing point

Given a vector and a camera (position, angle, up vector, field of view, etc), how would I find the vanishing point of the vector in camera space?
0
votes
1answer
75 views

Free camera rotation in 3D space

I'm using a view matrix to do camera movement and rotation. viewMatrix = new Matrix4f(); viewMatrix.setIdentity(); Matrix4f.rotate((float) Math.toRadians(rx), new Vector3f(1,0,0), viewMatrix, ...
1
vote
2answers
118 views

GLFW / OpenGL location and size in pixels

I'm using GLFW to create a little game. (and by little, I mean: small, nonprofit) After a while of puzzling, I found out that this draws a texture (from an image, for instance) to the screen: (the ...
2
votes
0answers
97 views

Cannot convert bitmap to texture [closed]

I'm doing a little C# / OpenGL project and I can't manage to load textures properly. So here is my texture class : public class Texture { public String Filepath; private int TextureID; ...
-1
votes
1answer
48 views

Java libgdx get clicked square without iter

I would like to detect which square is clicked without iterating over all elements! i don't want to do this anymore for all elements. if( x >= this.getAnchorX()-HalfWidth && x <= ...
4
votes
1answer
402 views

Skeletal animation in OpenGL

I'm using Assimp to do skeletal animation in my OpenGL application. I used Blender to export this one-boned model to a COLLADA file: The model has only one bone, called arm bone, that controls the ...
2
votes
1answer
138 views

Drawing fonts with LWJGL3 with OpenGL

I'm very sorry if this question has already been answered, but since I've been struggling with this for many days I thought I'd give it a shot here. My goal is to somehow render some text on the ...
1
vote
1answer
66 views

How to only render fragments with Z from 0 to 1 in OpenGL?

I have been using OpenGL for a year now, but I just recently found out that OpenGL only clips vertices when the absolute value of the x,y or z coordinate is less than the absolute value of w ...
0
votes
1answer
76 views

wrongly scaled on cocos2dx 3.2 when render to multiple fbo (more > 1 deep)?

i have bug that only happen when retina flag disabled. i try draw multiple render texture to achive some multi post effect: so i have 3 render texture, fbo 1 for final pos effect fbo 2 for back ...
1
vote
2answers
132 views

Rotating a swinging sword in LWJGL gives wierd results

I'm making a 2d top down game in Java using LWJGL(OpenGL, essentially). I recently tried adding a swinging sword mechanism. My coordinate system is set to the bottom left FOR ALL objects. The rotation ...
0
votes
0answers
39 views

In OpenGL on Android, how do I give quads a border color?

I am new to game development and I'm working on a Rubiks cube game in Android using OpenGL. I want to create a cube with black borders, but I can only manage to set the fill color: GLColor[] colors ...
0
votes
1answer
76 views

How to draw 2d above 3d scene?

I have an OpenGL(3.3)+GLEW application. I want to draw a black vertical rectangle at the left side of the window for writing some information on it, like fps (I use GLEW function for drawing text). ...
0
votes
0answers
51 views

Shader - Simple SSS lighting issue

I am trying to create a simple subsurface scattering effect using a shader but I am facing a small issue. Look at those screenshots. The three images represents three lighting states (above surface, ...
0
votes
1answer
85 views

loading a texture in Opengl

I am working on a graphics project I want to make a city using opengl with c++ anyway in the last few days I have been trying to load a texture but it didn't work with me in any way I have tried many ...
1
vote
2answers
42 views

glutPostRedisplay() is not redrawing after updating model view matrix

I am trying to change the rotation of my object with keyboards, when I move the object in the direction of x, y or z it is okay, it is responding correctly. But when I try to change rotation, it does ...
0
votes
3answers
131 views

Editing the pixels of a rendered image

I want to render a simple OpenGL scene as usual, but then I want to superimpose a small image of my own (such as from a bitmap file) on top of the render, such that this image always shows. For ...
1
vote
0answers
25 views

ThreadAffinity being changed by OpenGL / ChoosePixelFormat

If I change thread affinity and then create the window used in my OpenGL game it changes the thread affinity to something else. I tracked down the exact API call (ChoosePixelFormat) which changes it ...
4
votes
2answers
688 views

What state is stored in an OpenGL Vertex Array Object (VAO) and how do I use the VAO correctly?

I was wondering what state is stored in an OpenGL VAO. I've understood that a VAO contains state related to the vertex specifications of buffered vertices (what attributes are in the buffers, and what ...
0
votes
0answers
35 views

Coordinates estimation

Hi im using artoolkit to extract the coordinates of the marker im detecting with the camera. I need to know the values returned when arGetTransMat is the coordinates (x,y,z) which is returned ...
0
votes
0answers
49 views

How to calculate multiple collision of sphere and triangles?

I have a sphere and a mesh(triangles). When the sphere intersects the triangle, I reflects the vector of speed and everything works fine. But I can't write a good implementation for multiple ...
0
votes
0answers
44 views

Creating Lighting effect in openGL [duplicate]

I am trying to make my wall have the same color and shade as the walls shown in the picture (Please ignore the frame and the bulbs). I can create a a cube and view it from inside but how can we give ...
0
votes
1answer
101 views

Small text is very light / faint with FreeType and OpenGL

I'm able to render large text with FreeType just fine: But when I want to render small text (and the only parameter that changes is the font size), the quality is much poorer: As you can see, ...