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
2answers
69 views

glGenVertexArrays causes crash

My code keeps crashing at runtime, I have done some creative debugging and determined that it was the glGenVertexArrays that was causing the crash, I've looked around and come across some answers that ...
0
votes
1answer
23 views

Providing texture coordinates and using indexed drawing at the same time

Please consider the following vertex structure struct vertex { vec3 posL, normalL; }; Using this vertex layout, we can provide the vertex data in an interleaved way, i.e. ...
0
votes
0answers
34 views

OpenGL camera Rotation Matrix & view Transformations [on hold]

Recently i implemented a simple Opengl program that composes of a scene of objects, i've applied most of the transformation & projection matrices, in such away that i am able to rotate transform ...
2
votes
1answer
28 views

How do I fit the camera frustum inside directional light space?

I'm trying to improve the coverage of a shadow map for a directional light. Currently, it works great if the camera is looking straight down. However, if the camera is close to the ground and looking ...
0
votes
0answers
28 views

World, View, Projection concept - history [on hold]

I've got some unusual question, actually I would like to know something about the history of the World-View-Projection concept. Where did it come from? When was it used first? Does it exist since DX ...
0
votes
0answers
18 views

Most efficient way of brighten and darken sprites with libGDX1.0

So I have been shading (brighten/darken +adding color) my sprites by using glTexEnvf with GL_MODULATE and GL_ADD and a vertex color. I only had to rebind the batch every time I needed to change from ...
0
votes
0answers
29 views

Focus a turntable style camera on an object

I have a turntable style camera in the maya / blender / alembic / opensubdiv example. I want to be able to match the camera translation to any objects translation pivot point in the scene and then ...
3
votes
1answer
59 views

Should my GLSL Shader object/wrapper encapsulate loading/setting a VertexArrayObject?

I am working on a 2D game in C++, with a simple rendering layer over OpenGL. I have a wrapper for GLSL shaders and shader programs, these wrappers encapsulate shader objects into C++ classes and ...
0
votes
0answers
22 views

Keeping relative size with different resolution

I'm making a GUI system and want the components having a konstant relative size, even if I'm changing the resolution. Since I'm using the relative OpenGL coordinates to place them, there is no ...
0
votes
0answers
28 views

Loading Wavefront Data into VAO and Render It

I have successfully loaded a triangulated wavefront(.obj) into 6 vectors, the first 3 vectors contain the locations for vertices, uv coords, and normals. The last three have the indices stored for ...
0
votes
1answer
282 views

Using Shader causes triangle to disappear

The following is my rendering code. Private Sub GameRender() GL.Clear(ClearBufferMask.ColorBufferBit + ClearBufferMask.DepthBufferBit) GL.ClearColor(Color.SkyBlue) ...
3
votes
3answers
126 views

Make openGL program only update every 1/60 seconds

I'm learning C++ and openGL and have this program as a result from tutorials and playing around. The problem is that the main loop is running at "full speed", making the program unnecessarily cpu ...
1
vote
0answers
31 views

Why am I not getting an sRGB default framebuffer?

I'm trying to make my OpenGL Haskell program gamma correct by making appropriate use of sRGB framebuffers and textures, but I'm running into issues making the default framebuffer sRGB. Consider the ...
4
votes
1answer
176 views

OpenGL rendering looks squeezed

I am rendering bunch of cubes of unit size, but for some reason they look like they are squeezed a bit in the screen-space y axis. Why is this? My projection matrix: Projection = ...
2
votes
1answer
84 views

Mouse Speed in GLUT and OpenGL?

I would like to simulate a point that moves in 2D. The input should be the speed of the mouse, so the new position will be computed as following new_position = old_position + ...
2
votes
1answer
136 views

C++ FPS game collision detection with partitioning system or physics engine?

I'm working on a small FPS game (as a hobby and for learning purposes, nothing else) built with C++ in OpenGL (from scratch). Documenting online on the kind of strategy someone would approach with ...
-1
votes
0answers
21 views

LWJGL camera rotation is pivoting around original point instead of around where it has been translated (w/ glRotatef)

I've been playing about with LWJGL and I've encountered a problem. When I move the player's camera and then rotate it, it appears to pivot around where the player originally was. How do I make it so ...
1
vote
2answers
205 views

Orthographic Zooming with 0,0 at top/left

I'm trying to implement zooming on my 2D game. Since it's using orthographic projection, I thought it would be easy to implement zooming. After looking around the internet, I found a bunch of ...
5
votes
2answers
486 views

atmospheric scattering and sky geometry

I'm trying to implement an atmospheric scattering in my graphics (game) engine based on the gpu gems article: link. An example implementation from that article uses a skydome. My scene is different - ...
1
vote
1answer
89 views

Performing manual clipping in OpenGL

I'm learning OpenGL and I understand that OpenGL performs clipping as part of the pipeline, but is it a good idea to also perform manual clipping? By manual clipping, I mean not asking the GPU to draw ...
0
votes
0answers
37 views

Mouse input that 'sucks in' particles [on hold]

I'm having trouble figuring out the equations behind the title, I did exactly this using OpenGL's fixed function pipeline, but while transferring this over to the programmable pipeline i'm running ...
0
votes
2answers
50 views

What dimensions should you use for a perspective projection frustum?

What dimensions should you use for a perspective projection frustum? Initially I created a perspective matrix based on the width and height of the screen, with a calculated zNear value based on a ...
0
votes
1answer
33 views

LWJGL Resize window and glTranslate breaking screen resolution

I'm trying to make a 2D Tile RPG game with LWJGL but I'm having a problem with the display resizing. I want the user to be able to re-size the window to whatever size they want just by expanding it ...
0
votes
2answers
128 views

OpenGL - How can I make the edges of this textured circle smoother?

I'm building a game and I've applied a certain texture (RAW file) to a circle (GL_POLYGON) in OpenGL. It loads correctly, with the right size and all, but the edges seem a bit jagged and I would ...
0
votes
2answers
230 views

LWJGL texture bleeding fix won't work

I tried a lot of things to fix texture bleeding, but nothing works. I don't want to add a transparent border around my textures, because I already got too many and it would take too much time and I ...
1
vote
1answer
108 views

Random lines away from images in java2d opengl game

Working on a java game that uses some pngs images for icons/textures. A few images ( fewer than 5, out of dozens ) are showing some odd parallel "artifact" lines. They move with the image, are ...
0
votes
1answer
234 views

LWJGL font not rendering, even with depth test and texture_2D

I'm running into an odd little problem here. I'm attempting to render a basic console over my LWJGL-based application, which should be easy enough through a decorator pattern of renderers (as in, one ...
1
vote
1answer
157 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 ...
2
votes
4answers
236 views

Why would you use software rendering over hardware rendering, today?

As opposed to CPU or software rendering I assume? Wouldn't generally all current rendering be GPU based, seeing as you would be using OpenGL or Direct X? Could someone give me some info here, can't ...
-1
votes
1answer
76 views

C++ SDL2 OpenGL Rendering Problems [closed]

I just started with SDL2 and OpenGL in C++ and I am having some trouble rendering a triangle. The triangle I want to draw renders on the screen, but it is black. I tried added some shaders, but they ...
0
votes
3answers
97 views

OpenGL: glRotatef cause performance drop while rotating -x and -y

I have made a rotating cube and I got some performance drops while using two glRotatef calls. So basically this code is giving me 80FPS: //code 1 GLrotate_x += 0.4f; GLrotate_y += 0.4f; ...
1
vote
1answer
207 views

How can I implement beam effects like these?

I am interested in the techniques I could use to create the following effects: Can I accomplish this with a particle system or a series of texture quads, or what? You can see this effects in ...
0
votes
1answer
77 views

translate-scroll repeated 2d texture using opengl shader

I managed to implement an infinite 2d texture scrolling using the following shader. btw I'm using cocos2d-x 2.2.1. The vertex shader: attribute vec4 a_position; attribute vec2 a_texCoord; #ifdef ...
1
vote
1answer
45 views

glOrtho setting view

I am duplicating this thread from stackoverflow, please remove it if that is not allowed. I'm completely new in OpenGL. I have this problem: I have quite a complicated scene, and I am looking at it ...
0
votes
1answer
95 views

Render scene twice in OpenGL, overlay second render with tranparency

Is it possible to render two scenes (same scene with different setups) without any alpha, and after that is done just overlay the result from the second render on top of the first layer with a static ...
0
votes
2answers
140 views

Do Java and Actionscript use OpenGL?

As far as I know there are only 3 base graphics libraries on Windows, the GDI, OpenGL and DirectX, is that correct, so that means that Java, Actionscript and all language use one of these 3 libraries ...
1
vote
1answer
72 views

Workaround the flip queue (AKA pre-rendered frames) in OpenGL?

It appears that some drivers implement a "flip queue" such that, even with vsync enabled, the first few calls to swap buffers return immediately (queuing those frames for later use). It is only after ...
2
votes
1answer
106 views

glDeleteTextures - release data, but keep the texture ID?

In OpenGL, is it possible to release texture data, but keep the same texture id? I want to unload textures when they aren't needed, but load them again later when they are. There are a lot of objects ...
0
votes
3answers
179 views

OpenGL - How to draw a transition of two textures on one quad?

I know when drawing a rectangle, if we select red and draw two vertices, and then select yellow and draw the other two vertices, the entire rectangle will show a nice transition of color between those ...
0
votes
0answers
33 views

Using multiple uniform blocks in OpenGL

I'm using OpenGL with JOGL and want to use two unfirorm blocks in my vertex and pixel shaders. The following GLSL-Code shows the definitions:- uniform perObject { Material uMaterial; mat4 ...
3
votes
0answers
88 views

OpenGL Shadow Mapping from directional light [on hold]

I have read this tutorial: http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-16-shadow-mapping/ I wonder, is this the current best technique for generating shadows in an arbitrary 3D ...
1
vote
1answer
388 views

How do I apply 2 rotations about different points to a single primitive using OpenGL

I'm working on a 2D top-down shooter game that has a rotation feature like Realm Of The Mad God such that if you press e the camera rotates around the character in a clockwise direction and q rotates ...
0
votes
2answers
132 views

Can I use multiple OpenGL version together

I want to use GLSL but keep my current OpenGL 1.1 setup. The thing is that can I use OpenGL 2.0 shaders on OpenGL 1.1 renders?
1
vote
1answer
198 views

Xbox Controller Not Connecting in Monogame Project

I have recently been playing around with the support of the wired XBox 360 controller in Windows development. I am developing in C# in Visual Studio 2012. I have created 2 projects. The first ...
1
vote
1answer
295 views

Fog shader camera problem

I have some difficulties with my vertex-fragment fog shader in Unity. I have a good visual result but the problem is that the gradient is based on the camera's position, it moves as the camera moves. ...
0
votes
1answer
98 views

OpenGL: How to improve the performance of rendering context [on hold]

I have written a benchmark program that compares the performance of OpenGL and DirectX libraries. The problem is that OpenGL gets much lower performance than Direct3D. At the end the program generates ...
2
votes
2answers
786 views

FBX Importer - Texture Name

I have a problem with the FBX SDK. I read in the data for the vertex position and the uv coordinates. It works fine, but now I want to read for each polygon to which texture it belongs, so that I can ...
0
votes
0answers
28 views

Get closed ring around a mesh passing through given points

Suppose I've some points on a mesh (2+) that can be anywhere on the mesh, suppose for example these (ignore the small points, just consider the sphere): http://i.stack.imgur.com/nDzW3.png (sorry ...
3
votes
2answers
90 views

Blending semi-transparent images while not stacking their alphas

In libgdx/OpenGL ES I want to render multiple semitransparent textures while keeping the alpha still semi transparent. For example If I render a 0.5 alpha circle on top of another 0.5 alpha circle, ...
2
votes
1answer
63 views

Possible to create transparency shader which doesn't stack alpha values

The image above best demonstrates what I'm trying to achieve. It's a transparent shader for objects, but wherever the objects with this shader intersect they don't add together but simply merge with ...