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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1answer
223 views

How to debug pyglet/opengl bus errors

I'm using pyglet for game development, and sometimes encounter "bus errors". They are not consistently repeatable, and whenever I try to do simple debugging (eg move/remove variables, etc), the errors ...
2
votes
1answer
834 views

Need some help implementing VBO's with Frustum Culling

i'm currently developing my first 3D game for a school project, the game world is completely inspired by minecraft (world completely made out of cubes). I'm currently seeking to improve the ...
2
votes
2answers
6k views

Getting error GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT

I am getting error code GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT when creating framebuffer on Mac (using glCheckFramebufferStatus). I am using same code for rendering on Mac and iOS both. Maybe problem ...
2
votes
1answer
534 views

Problem with arcball

I making graphics viewer, and I want to use "arcball" to manipulate object. I using OpenGL + CML ( for math ). My arcball don't want work, it is skewing not rotating :/ And I don't know why, I use ...
2
votes
1answer
496 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 ...
2
votes
1answer
641 views

Problem with gluOrtho2D()

I was trying to understand the gluOrtho2D function. I have drawn 4 lines originating from the center reaching up to 4 corners of the screen. You can follow the below code. osize is a variable which ...
2
votes
1answer
408 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. ...
2
votes
1answer
337 views

OpenGL Fast-Object Instancing Error

I have some code that loops through a set of objects and renders instances of those objects. The list of objects that needs to be rendered is stored as a std::map>, where an object of class ...
2
votes
1answer
2k views

Opengl-es picking object

I saw a lot of picking code opengl-es, but nothing worked. Can someone give me what am I missing? My code is (from tutorials/forums) Vec3 far = Camera.getPosition(); Vec3 near = ...
2
votes
2answers
369 views

How are red dot/reflex/holographic sights implemented?

In first-person-shooters like Call of Duty, the hologram only appears when it is behind the glass portion of the sight. In OpenGL, would it be implemented by rendering the glass to the stencil buffer ...
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5answers
1k views

OpenGL Performance Questions

This subject, as with any optimisation problem, gets hit on a lot, but I just couldn't find what I (think) I want. A lot of tutorials, and even SO questions have similar tips; generally covering: ...
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vote
4answers
2k views

searching for “university kind” free online course about OPENGL [closed]

I know there are a lot of free university courses, but I'm trying to find one about OpenGL. Do you know where can I find one, online?
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4answers
353 views

Are VBOs only for OpenGL 3.x?

Are VBOs only for OpenGL 3.x? I'm using immediate mode and I know it's bad, slow, and deprecated. But then I looked at display lists but they are deprecated too. I guess the VBO is the only one left ...
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vote
3answers
135 views

How to handle wildly varying rendering hardware / getting baseline

I've recently started with mobile programming (cross-platform, also with desktop) and am encountering wildly differing hardware performance, in particular with OpenGL and the GPU. I know I'll ...
1
vote
3answers
2k views

Is a Single Texture Cube Map Possible?

I'm currently developing a test project to explore OpenGL 3 texturing abilities. I have a simple cube, made of 8 vertices and 36 indices. I want each of the cubes faces to have a different texture, so ...
1
vote
5answers
5k views

OpenGL Insanely Slow [closed]

I'm learning C++, and I'm writing my first OpenGL program. Unfortunately, it seems to be defaulting to Software Rendering (CPU uses bounces, GPU uses stays at 1%). I'm using SDL as the Windowing ...
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vote
3answers
3k views

Will I have an easier time learning OpenGL in Pygame or Pyglet? (NeHe tutorials downloaded) [closed]

I'm looking between PyGame and Pyglet, Pyglet seems to be somewhat newer and more Pythony, but it's last release according to Wikipedia is January '10. PyGame seems to have more documentation, more ...
1
vote
3answers
200 views

Is it possible to gain performance by omitting vertex normals in the GPU pipe?

I am working on a rendering problem where I want to render as many raw triangles to the screen as I can with either OpenGL or DirectX with the absolute fastest performance possible. I wondered about ...
1
vote
1answer
1k views

Image loaded from TGA texture isn't displayed correctly

I have a TGA texture containing this image: The texture is 256x256. So I'm trying to load it and map it to a cube: #import <OpenGL/OpenGL.h> #import <GLUT/GLUT.h> #import ...
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3answers
592 views

OpenGL are strips/fans faster for rendering or just data bandwidth

When we send data for drawing we can mark it as TRIANGLE_STRIP or TRIANGLE_FAN to reduce the number of vertices we have to specify. Now, does this actually improve the rendering speed on the graphics ...
1
vote
2answers
738 views

Rendering (rasterization / ray tracing / others)

I'm completely new to this graphics and game development. I have read about Rendering (drawing a 3D graphic on a display 2D) and there are many ways of rendering, Rasterization, Ray tracing, ...
1
vote
2answers
2k views

OpenGL ES 2.0: Perspective Projection for 2D Games

Prespective Projection has features that could be very well used even in 2D games. At least two very beneficial characteristics that come to my mind are: Using Perspective Projection to substitute ...
1
vote
1answer
483 views

GL_INVALID_OPERATION in glEnd

I'm having problems drawing a simple sprite. When I draw: void CSprite2D::render() { CHECKGL(glLoadIdentity()); CHECKGL(glEnable(GL_TEXTURE_2D)); ...
1
vote
1answer
60 views

OpenGL Post Processing Introducing Artifacts on Certain Systems

Playing around with God-Rays in my framework, I was greeted with the following artifacts on my laptop: The artifacts themselves act almost like noise, flickering around the image rapidly. They also ...
1
vote
3answers
219 views

Rendering order

In this thread Rendering a model with transparent or translucent uv map applied doesn't work , I asked about what was wrong with my model that the transparency wasn't working. I've got an answer ...
1
vote
2answers
477 views

I enabled and setup glBlendFunc, but my texture has a white outline. What am I doing wrong?

You can see most of my source code in this question: Instead of the specified Texture, black circles on a green background are getting rendered. Why? Now I have the problem, that my texture has a ...
1
vote
1answer
904 views

rotating spheres

I want to continuously rotate 2 spheres, however the rotation does not seem to work. Here is my code: float angle = 0.0f; void light(){ glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); ...
1
vote
3answers
619 views

What should I use to handle input? [closed]

What should I use to handle input? I am wanting to use OpenGL so that my games are cross platform. DirectX provides input libraries, and OpenGL does not. Because my games need to be cross platform, I ...
1
vote
1answer
95 views

Why are my objects rotating with my camera?

I am working with this C# library that wraps OpenGL. I am trying to understand why my objects in the scene are rotating as I yaw my camera (view matrix). Here is an image where I have 4 separate ...
1
vote
2answers
840 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 ...
1
vote
1answer
163 views

Does opengl performs Visibilty algorithms based on z-index?

Does OpenGL performs Visibilty algorithms based on z-index? Or we have to write our own algorithms. Mainly I'm referring to z-buffer algorithm. Is it in-built?
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vote
2answers
3k views

What is the best method to update shader uniforms?

What is the most accepted way for keeping a shader's matrices up to date, and why? For example, at the moment I have a Shader class that stores the handles to the GLSL shader program & uniforms. ...
1
vote
2answers
2k views

Calculate object coordinates from window coordinates using inverse projection matrix

What I am trying to to is placing 3D Objects (A Sphere) in the world when I click there. I am using a perspective projection so the first step after calculating the canonical clip coordinates from ...
1
vote
3answers
2k views

Set a variable inside a GLSL fragment shader that persists for the render

Is it possible to set a varying variable inside a fragment shader and have it persist? I'd like to use the depth component of the first fragment and use it on all the others, making the fragments all ...
1
vote
4answers
2k views

How to pass one float as four unsigned chars to shader by glVertexPointAttrib?

For each vertex I use two floats as position and four unsigned bytes as color. I want to store all of them in one table, so I tried casting those four unsigned bytes to one float, but I am unable to ...
1
vote
2answers
5k views

How to implement explosion in OpenGL with a particle effect?

I'm relatively new to OpenGL and I'm clueless how to implement explosion. So could anyone give me some ideas how to start? Suppose the explosion occurs at location $(x, y, z)$, then I'm thinking of ...
1
vote
3answers
851 views

Shaders not linking correctly

I'm writing a rather simple "ShaderManager" which aids me with loading shaders in Open GL, altough I am having a few issues: The shaders don't link correctly The the attributes don't bind Here's ...
1
vote
2answers
540 views

What is the better approach to redraw a static background scene for game?

Take for an example I have the background scene of a game which should remain static for an interval.Then for every time redrawing the scene,is it better for me to store the color buffer for every ...
1
vote
2answers
397 views

Should SIMD be used by people who are new to game development?

I have been learning game development, using C++ and OpenGL, for about 4-5 months. Before that I used to program in C# and the .NET platform(about a year). So, I consider myself new to game ...
1
vote
2answers
379 views

Does Blitz3D use its own 3D engine or does it wrap OpenGL?

How does Blitz3D work? I mean internally, does it use OpenGL with basic wrappers or it using some open source 3D engine that itself wraps OpenGL?
1
vote
2answers
574 views

OpenGL Camera causes spatial distortion

I'm trying to implement a 3D camera of the "Orbit around the origin" variety in a game engine I'm developing in order to learn about 3D graphics and game programming. I have a basic handle on the ...
1
vote
2answers
6k views

OpenGL ES 2.0: Controlling Transparency in Fragment Shader

The following is the OpenGL ES 2.0 simple GLSL Fragment Shader, I use to place textures on polygons, to render 2D sprites. varying mediump vec2 TextureCoordOut; uniform sampler2D Sampler; void ...
1
vote
2answers
694 views

Collision Problems

I'm having some troubles with a 2D platformer type game (there's more to it, but that's all that matters for this question). I had collision with the platforms working fine, but if the character hit ...
1
vote
3answers
85 views

Rendering many similar objects [closed]

I am writing an city builder. The graphics should look pretty simple, there are no fancy models or textures. Something like Synekism. Thus I have only simple models for buildings and splines for ...
1
vote
2answers
106 views

Difference between Spherical Harmonics and Spherical Harmonics Lighting

What is the difference between Spherical Harmonics and Spherical Harmonics Lighting in OpenGL?
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vote
2answers
332 views

C++, OpenGL: Building a polyhedron via geometry shader

I'm stuck with geometry shaders in OpenGL - c++ programming. I want to create simple cube by repeating 6 times drawing one rotated wall. Here is my vertex shader (everyting has #version 330 core in ...
1
vote
1answer
104 views

It possible to render a true quad (without triangles) using OpenGL?

Is it possible to render a "true" quad in OpenGL? By that I mean a square which is not made out of two triangles.
1
vote
2answers
342 views

How can rotate a 2D textured quad in legacy OpenGL immediate mode?

I have a texture of a tank, and I want to it appearance on the screen depends on its current direction, so I decided to use rotating texture functions of OpenGL. I followed some advices through Google ...
1
vote
1answer
89 views

OpenGL - Buffer Usage

I am currently working on a little OpenGL project. At the moment I am trying to find a good solution for rendering multiple objects. I have set up a terrain with its own buffers, which works just ...
1
vote
1answer
509 views

Shadow map: depth texture always returns 0

I'm implementing a shadow map for the sun light in my voxel engine using a depth texture attached to a framebuffer. But when I sample the depth texture during the normal pass, the value returned is ...