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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exporting bind and keyframe bone poses from blender to use in OpenGL

EDIT: I decided to reformulate the question in much simpler terms to see if someone can give me a hand with this. Basically, I'm exporting meshes, skeletons and actions from blender into an engine ...
6
votes
3answers
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Understanding how to create/use textures for games when limited by power of two sizes

I have some questions about the creating graphics for a game. As an example. I want to create a motorbike. (1pixel = 1centimeter) So my motorbike will have 200 width and 150 height. (200x150) But the ...
5
votes
3answers
561 views

How to skip the sky in lighting shaders?

I recently implemented a sky in my deferred rendered game. It is a procedurally calculated sphere with a texture applied to it. Unfortunately all lighting shaders (light sources, ambient occlusion) ...
5
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2answers
1k views

Can frequent state changes decrease rendering performance?

Can frequent texture and shader binding decrease rendering performance? "Frequent" binding example: for object for material in object render part of object using that material "Low count" ...
5
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2answers
1k views

Generating geometry when using VBO

Currently I am working on a project in which I generate geometry based on the players movement. A glorified very long trail, composed of quads. I am doing this by storing a STD::Vector, and removing ...
4
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1answer
875 views

OpenGL FBO not being drawn to

In my project I'm trying to implement a deferred rendering system, problem is, I can't seem to get a second FBO to work. UPDATE 1 Here is the FBO initialization code: /// G-Buffer FBO GLuint ...
4
votes
3answers
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OpenGL additive blending not working as expected

I am trying to achieve additive blending with point sprites. When the sprites overlap, all I get is solid red, when I expect to get a smooth blend from red->yellow->white. My sprite texture has all ...
4
votes
3answers
1k views

Voxel engine artifacts

There are white little dots between blocks at random places, mainly at very near blocks. They disappear when I move the mouse and change the view direction. I use Vertex Arrays with ...
4
votes
2answers
7k views

FrameBuffer Render to texture not working all the way

I am learning to use Frame Buffer Objects. For this purpose, I chose to render a triangle to a texture and then map that to a quad. When I render the triangle, I clear the color to something blue. ...
3
votes
5answers
961 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 ...
3
votes
2answers
2k views

When is the Z coordinate normalized in GLSL?

I thought that whenever you transform an object to world space, then view space and finally screen space, the last matrix you apply(the projection matrix) normalizes the z values between 0 and 1. ...
3
votes
2answers
976 views

How to subdivide a quad?

I'm working with OpenGL and I'm importing from a file coordinates for quads in the following format: 0.0 1.0 0.0 //normal vector 20.0 -5.0 20.0 10.0 10.0 //x y z u v 20.0 -5.0 -20.0 10.0 0.0 ...
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votes
2answers
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Creating map files for a 3D game

I've created plenty of 2D games and now that I've gotten my hands dirty working with 3D in opengl I want to start a game. The issue is I don't know how I can store all the map data. Not only the ...
3
votes
2answers
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My Ambient lighting is not working correctly

I'm having a problem when using ambient lights in my opengl game. When I first started with my program, i had a positioned light, and the code was this: GLfloat AmbientColor[] = ...
2
votes
2answers
537 views

Palette reduction to pre-defined palette

I'm writing a bunch of GLSL effects for fun, but I can't wrap my head around this. Basically, I want to reduce a texture's palette into a pre-defined set of colors. For example, a post-processing ...
2
votes
2answers
6k views

How to check for cube collisions?

I want a method, which takes two "ObjectBox" objects (A "ObjectBox" has .getX() .getY() .getZ() .getSizeX() .getSizeY() .getSizeZ() methods) as a parameter and return true if the two Boxes are ...
2
votes
1answer
676 views

Camera scrolling and game boundaries

I am making a platformer game in JBox2D and LWJGL that has a scrolling camera, but I have hit a wall with the boundaries of the camera. Essentially what I have right now is a Box2D world that is ...
2
votes
1answer
1k views

does glBindAttribLocation silently ignore names not found in a shader?

Does glBindAttribLocation silently ignore names that are not found? For example, in a shader: // Some vertex shader in vec3 position; in vec3 normal; // ... And in some set up code: // While ...
2
votes
4answers
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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?
2
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1answer
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How to detect GLSL warnings?

After compiling a shader with glCompileShader, I can call glGetShaderiv with GL_COMPILE_STATUS to check if the shader compiled successfully. I can also call glGetShaderInfoLog to get information about ...
2
votes
2answers
6k views

Is there any opengl cel shading tutorial out there (without GLAUX)?

I want to implement cel shading into my opengl game. I have only found a nehe tutorial that uses glaux (old as hell). I'm looking into it, but I wanna avoid the pain of learning how to translate those ...
1
vote
2answers
100 views

Cursor position to a 3D ray using angles

I've been stuck for a month trying to get gluUnProject working. After my attempts to use gluUnProject failed (as well as attempts to implement gluUnProject functionality manually) I implemented method ...
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vote
2answers
7k 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
5answers
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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: ...
12
votes
5answers
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Learning OpenGL: Red and Blue book still relevant?

I've recently purchased the Orange book( GLSL ) and am wondering if it is important at all to read through the red and blue books as well? Any thoughts?
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votes
5answers
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Is GLUT obsolete?

A question was asked about good, up-to date OpenGL resources, one of the answers was a link to a tutorial about modern OpenGL programming. The tutorial in question uses GLUT and GLEW, but I have read ...
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6answers
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AAA Games and OpenGL?

What modern AAA games on the top of the market used OpenGL? If applicable, what engine did they use?
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3answers
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How long does it take for OpenGL to actually update the screen?

I have a simple OpenGL test app in C which draws different things in response to key input. (Mesa 8.0.4, tried with Mesa-EGL and with GLFW, Ubuntu 12.04LTS on a PC with NVIDIA GTX650). The draws are ...
8
votes
1answer
4k views

SDL2 with OpenGL — weird results, what's wrong?

I'm porting an app to iOS, and therefore need to upgrade it to SDL2 from SDL1.2 (so far I'm testing it as an on OS X desktop app only). However, when running the code with SDL2, I'm getting weird ...
6
votes
2answers
3k 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 ...
6
votes
1answer
318 views

Get SFML to report the version of OpenGL that is being used

How can I get SFML to report the version of OpenGL that is being used by the render window?
6
votes
1answer
512 views

Display Lists in OpenGL

I heard that there was a faster method of displaying vertices, rather than recreating the GL_TRIANGLES, each time the scene is drawn. I thought I read somewhere that this method was obselete. Why ...
6
votes
2answers
369 views

Changing player color without multiple player bitmaps [duplicate]

Possible Duplicate: How to colorize certain parts of a model - like RTS games have those team colors? Ok, so here is my current situation. I have a player model, fully UV mapped, and ...
6
votes
1answer
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gl_PointCoord always zero

I am trying to draw point sprites in OpenGL with a shader but gl_PointCoord is always zero. Here is my code Setup: //Shader creation..(includes glBindAttribLocation(program, ATTRIB_P, "p");) ...
5
votes
1answer
139 views

Textures “don't work” when I don't specify any texture parameters. Is this a driver bug or intended behavior?

Whenever I try to use textures, I have to at least specify the sample filtering parameters (GL_TEXTURE_MAG_FILTER, GL_TEXTURE_MIN_FILTER) for textures to work at all. If I don't, sampling the textures ...
5
votes
1answer
3k views

What is the recommended way to output values to FBO targets? (OpenGL 3.3 + GLSL 330)

I'll begin by apologizing for any dumb assumptions you might find in the code below since I'm still pretty much green when it comes to OpenGL programming. I'm currently trying to implement deferred ...
5
votes
1answer
852 views

Cheap ways to do scaling ops in shader?

I've got an extensive world terrain that uses vec3 for the vertex position attribute. That's good, because the terrain has endless gradations due to the use of floating point. But I'm thinking about ...
5
votes
1answer
319 views

Can I leverage the fact that my scene is often static to improve OpenGL (JOGL) performance?

My scene is drawn based on the location of several (often several million) vertices (kept in VBO's) and a camera. I can easily tell in my code when my scene has changed and when it hasn't. There are ...
5
votes
1answer
1k views

What's the best way of drawing a glowing 3d line using LWJGL?

Sort of like a strip-light effect; not actually a light source, but just a polygon with glowing edges. Can this be done easily? Right now I'm contemplating drawing a line more than once with varying ...
4
votes
2answers
367 views

How does a general Renderer::drawRect(0, 0, 100, 100) handle VBO's?

Lots of game engines and GUI systems have a general Renderer class with functions like: renderer.drawRect(0, 0, 100, 100); renderer.drawText(204, 452, "Hello, world!"); I understand how this could ...
4
votes
3answers
2k views

Is “pure” OpenGL productive enough?

I know that this is a difficult question and I hope I can convey my meaning. Over time I've used many different engines from XNA over Unity to Panda3d and even tried native directX once. My final ...
4
votes
1answer
4k views

OpenGL ES 2.0: Moving Camera in Orthogonal (2D) Projection

I have quite large 2D game scene. The scene is much larger than the screen of the LCD. Therefore, I have to move the camera (view) in desired directions, to display particular parts of the scene. ...
3
votes
1answer
155 views

what is the very last element of a 4x4 transformation matrix for? [duplicate]

while its a similar value to its neighbour - Z translation (and I wont say if thats above or to the left for fear of sparking a religious war!) and it only seems to change when the Z translation value ...
3
votes
1answer
658 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 ...
3
votes
1answer
3k views

smooth shading vs flat shading, what's the difference in the models?

I'm loading the exact same model with Assimp, except one is exported from Blender, shaded smoothly, and the other was exported from Blender, shaded flatly. Here is my results from loading both into my ...
3
votes
2answers
293 views

Instead of the specified Texture, black circles on a green background are getting rendered. Why?

I'm trying to render a Texture via OpenGL. But instead of the texture black circles on a green background are rendered. (They scale, depending what the rotation of the texture is) Example: The ...
3
votes
2answers
8k views

Map and fill texture using PBO (OpenGL 3.3)

I'm learning OpenGL 3.3 trying to do the following (as it is done in D3D)... Create Texture of Width, Height, Pixel Format Map texture memory Loop write pixels Unmap texture memory Set Texture ...
3
votes
1answer
2k views

Can't get LWJGL lighting to work

I'm trying to enable lighting in lwjgl according to the method described by NeHe and this post. However, no matter what I try, all faces of my shapes always receive the same amount of light, or, in ...
3
votes
4answers
2k views

Multiplatform GLSL shader validator?

Im working on a multiplatform (Pc,Mac,Linux) game that uses shaders quite extensively. Since we do not have any funding, it is pretty hard to test our game on all possible hardware configurations. ...
3
votes
1answer
2k views

OpenGL ES Basic Fragment Shader help with transparency

I have just spent my first half hour playing with the shader language. I have modified the basic program I have which renders the texture, to allow me to colour the texture. varying vec2 texCoord; ...