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

2
votes
1answer
286 views

Masking OpenGL texture by a pattern

Tiled terrain. User wants to build a structure. He presses build and for each tile there is an "allow" or "disallow" tile sprite added to the scene. FPS drops right away, since there are 600+ tiles ...
0
votes
2answers
321 views

Normal maps red in OpenGL?

I am using Assimp to import 3d models, and FreeImage to parse textures. The problem I am having is that the normal maps are actually red rather than blue when I try to render them as normal diffuse ...
0
votes
1answer
450 views

Problems when rendering code on Nvidia GPU

I am following OpenGL GLSL cookbook 4.0, I have rendered a tesselated quad, as you see in the screenshot below, and i am moving Y coordinate of every vertex using a time based sin function as given in ...
-1
votes
1answer
355 views

OpenGL - zNear and zFar Parameters

I am trying to figure out what each parameter does. In the meantime I am playing around with glOrtho . I have already understood how everything works except zNear and zFar .
0
votes
1answer
203 views

Making video from 3D gaphics in OpenGL

What are some of the preferred methods or libraries for creating video from an OpenGL graphics simulation? For example, I want to create a visualization(video) of an N-Body gravity simulation by ...
0
votes
3answers
425 views

What are the semantics of glRotate and glTranslate's parameters?

I have been trying to play with OpenGL after watching some tutorials and I don't understand how the glTranslatef and glRotatef functions work. I believe a simple picture would help me. I understand ...
2
votes
2answers
1k views

std::map for storing static const Objects

I am making a game similar to Minecraft, and I am trying to fine a way to keep a map of Block objects sorted by their id. This is almost identical to the way that Minecraft does it, in that they ...
5
votes
4answers
674 views

Creating a voxel world with 3D arrays using threads

I am making a voxel game (a bit like Minecraft) in C++(11), and I've come across an issue with creating a world efficiently. In my program, I have a World class, which holds a 3D array of Region ...
1
vote
0answers
273 views

GLSL, Internal error: assembly compile error for fragment shader at offset 513 [closed]

My vertex and fragment shaders link correctly. When I try and link my shader program I get the error: "Internal error: assembly compile error for fragment shader at offset 513". Pastebin of fragment ...
1
vote
0answers
142 views

Bad texture on model with different GPU [closed]

I have some kind of distortion on the texture of my 3D model. It works perfectly well on an AMD GPU, but when testing on a integrated Intel HD graphics card it has a weird issue. I don't have a ...
0
votes
1answer
85 views

Texture errors in CubeMap

I am trying to apply this texture as a cubemap. This is my result: Clearly I am doing something with my texture coordinates, but I cannot for the life of me figure out what. I don't even see a ...
4
votes
2answers
559 views

What Shading/Rendering techniques are being used in this image?

My previous question wasn't clear enough. From a rendering point of view what kind of techniques are used in this image as I would like to apply a similar style (I'm using OpenGL if that matters): ...
1
vote
1answer
237 views

Understanding implementation of glu.PickMatrix() [closed]

I am working on an OpenGL project which requires object selection feature. I use OpenTK framework to do this; however OpenTK doesn't support glu.PickMatrix() method to define the picking region. I ...
4
votes
1answer
379 views

“exception at 0x53C227FF (msvcr110d.dll)” with SOIL library

I'm creating a game in C++ using OpenGL, and decided to go with the SOIL library for image loading, as I have used it in the past to great effect. The problem is, in my newest game, trying to load an ...
3
votes
1answer
384 views

Multiple texture coordinates per mesh?

So far I've used the same texture coordinate for both the normal and diffuse textures on a mesh, yet when reading the Assimp documentation ...
1
vote
1answer
116 views

What is w componet [duplicate]

What is the W component on graphics programming. I read a blog about opengl that says that w must be equal to either 0 or 1 here. But the book I am currently reading has put w component to more than 1 ...
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); ...
0
votes
1answer
366 views

Problems with 3D Array for Voxel Data

I'm trying to implement a voxel engine in C++ using OpenGL, and I've been working on the rendering of the world. In order to render, I have a 3D array of uint16's that hold that id of the block at the ...
3
votes
4answers
879 views

How many times fragment shader is executed?

I have an OpenGL code, with 3 different shader programs. I have a simple question, I know fragment shaders are executed for every every fragment in the scene. But is there a way using which we can ...
6
votes
1answer
828 views

Efficiently rendering to 3D texture

I have an existing depth texture and some other color textures, and want to process the information in them by rendering to a 3D texture (based on the depth contained in the depth texture, i.e. a ...
3
votes
2answers
120 views

Are buffers in OpenGL associated with GLSL programs?

I have two different shader programs in my OpenGL code. 1- renders simple font using freetype 2- simple shader which draw primitive shapes. I sent both of them some data using buffers, I understood ...
1
vote
1answer
243 views

Sprite rotation

I'm using OpenGL and people suggest using glRotate for sprite rotation, but I find that strange. My problem with it is that it rotates the whole matrix, which sort of screws up all my collision ...
2
votes
3answers
909 views

Visitor-pattern vs inheritance for rendering

I have a game engine that currently uses inheritance to provide a generic interface to do rendering: class renderable { public: void render(); }; Each class calls the gl_* functions itself, ...
-1
votes
1answer
340 views

Detailed Modern Opengl Tutorial? [duplicate]

I am asking for a specific modern opengl tutorial. I need a tutorial that does not skip to explain any lines of code. It should also include different independent objects moving/rotating (most ...
1
vote
2answers
2k views

Drawing multiple objects from one Vertex Buffer Object in OpenGL/OpenTK

I am trying to experimenting drawing method using VBO in OpenGL. Many people normally use 1 vbo to store one object data array. I was trying to do something quite opposite which is storing multiple ...
0
votes
1answer
921 views

GLSL billboard move center of rotation

I have successfully set up a billboard shader that works, it can take in a quad and rotate it so it always points toward the screen. I am using this vertex-shader: void main(){ vec4 tmpPos = (MVP * ...
14
votes
1answer
1k views

Normals vs Normal maps

I am using Assimp asset importer (http://assimp.sourceforge.net/lib_html/index.html) to parse 3d models. So far, I've simply pulled out the normal vectors which are defined for each vertex in my ...
1
vote
1answer
2k views

How to use mipmap in OpenGL-ES

I have recently entered in the OpenGL world. I am very pleased with the performance that I got with opengl compared to those obtained with a SurfaceView and its canvas. At the same time because of the ...
2
votes
1answer
1k views

OpenGL slower than Canvas

Up to 3 days ago I used a Canvas in a SurfaceView to do all the graphics operations but now I switched to OpenGL because my game went from 60FPS to 30/45 with the increase of the sprites in some ...
3
votes
1answer
446 views

Why is SpriteBatch.end() generating null pointer exception in this code?

I am getting a null pointer exception using libGDX that the debugger points as the SpriteBatch.end() line. I was wondering what would cause this. Here is the offending code block, specifically the ...
0
votes
2answers
119 views

view if GL_CULL_FACE is enabled/disabled

Im using GL_CULL_FACE, an i'm trying to map a key for enable/disable the gl_cull_face. Is there any posibility of viewing if it's enabled or not? Thanks
1
vote
1answer
258 views

How to only render part of an image in lwjgl/openGL

I'm making a mining/building game in java using slick2D and I want to make it so you can only see a few blocks in any direction while you are underground. The best example I could find of what I want ...
0
votes
1answer
490 views

How to deallocate/release/delete of a glTexStorage2D?

I tried to find this but found nothing. Does anyone know how to 'deallocate' textures/mipmap from glTexStorage2D once you don't need it anymore?
0
votes
1answer
605 views

I get GL_INVALID_VALUE after calling glTexSubImage2D

I am trying to figure out why my texture allocation does not work. Here is the code: glTexStorage2D(GL_TEXTURE_2D, 2, GL_RGBA8, 2048, 2048); glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 2048, 2048, ...
3
votes
1answer
382 views

Material, Pass, Technique and shaders

I'm trying to make a clean and advanced Material class for the rendering of my game, here is my architecture: class Material { void sendToShader() { program->sendUniform( ...
0
votes
1answer
140 views

Mesa 9.2 does not support OpenGL 3

I'm trying to install OpenGL 3.0 for studying examples about GLUS , which require OpenGL 3 or 4. I read on the official Mesa website that Mesa 9.2 support OpenGL 3.0, but after I installed Mesa 9.0, ...
0
votes
0answers
90 views

Triangle Clipping

I want to determine which part of a triangle is visible in a frustum in OpenGL, is there a way to get visible coordinates of triangle in the viewing frustum?
3
votes
1answer
226 views

How to Construct a Perspective Projection With 4 Vanishing Points

Is it possible to construct a projection matrix which will create a perspective with four (or more) vanishing points? This question have an OpenGL tag, but general insights are welcomed as well.
2
votes
1answer
477 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 ...
0
votes
1answer
185 views

Implementing smooth object rotation

I declared two variables on class level. One is the angle the object is rotated by. The second is a stopwatch. float yRot = 0.0f; static CStopWatch rotTimer; I rotate the cube using the SpecialKeys ...
2
votes
1answer
198 views

How stencil buffer and glFrontFace help making a shadow?

I'm trying to understand the tutorial 27th in Nehe website. This is about how to cast a shadow of an object using stencil buffer in OpenGL. The idea here is checking the directions of all the faces of ...
0
votes
1answer
76 views

Displaying normals of a geometry

I have a rectangle which is created by 2 triangles and it is in x-z plane, and i have object on it. Now, the normals of two triangles (face normals) are y axis i.e. (0,1,0). I want to display normals ...
4
votes
3answers
2k views

Implementing skeletal animation and GPU skinning (DOOM MD5)

DISCLAIMER This question has been completely rewritten to narrow the scope of the question in light of previous suggestions and answers, but the same problem still persists. Currently I'm trying to ...
0
votes
1answer
2k views

rotating 3D object around the center

I have object moving from A to B on x-axis and there is no translation of object apart from it. Now, while moving, i want to rotate it around y-axis and the motion should change accordingly, i mean if ...
0
votes
1answer
108 views

What input and window handler should I learn for complement OpenGL? [closed]

I have a good base in C++ programming and I did some 2D games using SDL. Now I want to start making 3D games, but as much as posible, I want to learn following the standars of the profesional ...
0
votes
1answer
494 views

How to move a rectangle properly?

I recently started to learn OpenGL. Right now I finished the first chapter of the "OpenGL SuperBible". There were two examples. The first had the complete code and showed how to draw a simple ...
0
votes
1answer
354 views

How to draw a rotatable and zoomable sphere?

My game is a sort of business simulation game of Earth, and I want the main interface to be just like a google earth view. Is there a way to do this with built in OpenGL features or do I have to ...
5
votes
1answer
650 views

OpenGL ES 2.0 obscured texture is visible

Hi, I am using LibGDX and OpenGL 2.0 to create a game. So far I have created two meshes. The front mesh is the one with the brown circle texture and another mesh on the top with a green to white ...
3
votes
1answer
194 views

Convert global rotation into local rotation

I have an object in my game and I have its location, rotation and scaling in separate float[3]. The location rotation and scale are all on the global axis; these do not change based on the objects ...
2
votes
1answer
269 views

Proportional speed movement between mouse and cube

Hi i´m trying to move a cube with the freeglut mouse "glutMotionFunc(processMouseActiveMotion)" callback, my problem is that the movement is not proportional between the mouse speed movement and the ...