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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162 views

What is “ping pong” in the context of graphics rendering?

I have to render a scene, once per light, and blend the result of the various passes. I heard and read that one way to increase performances and render targets to use would be ping pong. I'm new to ...
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0answers
12 views

Render on texture with alpha 0 for the background colour

Sorry if the question is stupid but I am very new to opengl. I render on a target a scene with a couple of object on a background that is nothing more than the clear colour (which is ...
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1answer
80 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 ...
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0answers
44 views

Object not texturing properly [on hold]

So I am trying to texture a cube, however things aren't quite turning out as planned. The results always look similar to this: Where in this picture the texture is supposed to be a red/black ...
3
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0answers
74 views

How to avoid subpixel values in a resolution independent 2D game with orthographic projection?

I'm trying to do resolution independent rendering of moving sprites in a 2D game. My plan is work in a fixed coordinate system in my world (for example 960x540) and use orthographic projection to ...
3
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1answer
91 views

Using textureGrad for anisotropic integration approximation

I'm trying to develop a real time rendering method using real time acquired envmap (cubemap) for lightning. This implies that my envmap can change as often as every frame and I therefore cannot use ...
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0answers
19 views

Shader | Special Effect - Unit selection [duplicate]

I would like to know how the shaders used to show which unit is selected are made. Here is an image to illustrate. How the merge effect of the blue circles can be achieved ? I didn't found any ...
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vote
1answer
169 views

Understanding implementation of glu.PickMatrix()

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 ...
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1answer
46 views

Using depth texture for depth testing

I was wondering if it is possible to render my scene onto a depth texture then using that texture for depth testing in another pass. I have an idea to that in shaders, but is that possible ...
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0answers
61 views

Gaussian blur not working correctly

So pretty much I tried to add a gaussian blur to something I am making and it is acting oddly. The setup is like: [All framebuffers are cleared to rgba(0,0,0,0), normal blend enabled] Draw some solid ...
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0answers
28 views

Problems with drawing billboards [on hold]

I am currently trying to draw billboards and some geometry with "modern opengl approach". Problem is that I cannot force billboards to keep their positions in space. I need to link text positions ...
1
vote
2answers
128 views

Application of classes with critical non-static fields in LWJGL

I'm going to be as specific about this question as I can. Ultimately, how is it that I apply a class that uses non-static fields in LWJGL? More specifically, I know that OpenGL is quite nearly more a ...
2
votes
1answer
137 views

Anti-Aliasing in OpenGL [C++]

I'm trying to make anti-aliasing work inside of OpenGL, here's what I've tried: glEnable(GL_POINT_SMOOTH); glHint(GL_POINT_SMOOTH_HINT, GL_NICEST); glEnable(GL_LINE_SMOOTH); ...
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vote
1answer
55 views

Vertex shader in OpenGL/GLSL - transformation of the interior of a textured quad

I have a LWJGL project and ran into a problem with a vertex shader I wrote. In my scene I am rendering a map whose ground consists of rectangular tiles. On top of that there are other objects (I used ...
3
votes
1answer
99 views

How to calculate directional light frustum from camera frustum

I'm playing around with OpenGL for a few weeks now. For the following screenshot I picked the glm::ortho values for my lightsource by trial and error. There are two directional light sources with ...
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votes
1answer
183 views

Is there a standard way to track 2D tile positions both locally and on screen?

I'm building a 2D engine based on 32x32 tiles with OpenGL. OpenGL draws from the top left, so Y coordinates go down the screen as they increase. Obviously this is different than a standard graph ...
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1answer
47 views

Proper way to encapsulate a Shader into different modules

I am planning to build a Shader system which can be accessed through different components/modules in C++. Each component has its own functionality like transform-relevated stuff (handle the MVP ...
2
votes
1answer
171 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); ...
6
votes
3answers
385 views

State of the art Culling and Batching techniques in rendering [on hold]

I'm currently working with upgrading and restructuring an OpenGL render engine. The engine is used for visualising large scenes of architectural data (buildings with interior), and the amount of ...
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2answers
48 views

Taking fixed direction on hemisphere and project to normal (openGL)

I am trying to perform sampling using hemisphere around a surface normal. I want to experiment with fixed directions (and maybe jitter slightly between frames). So I have those directions: vec3 ...
2
votes
1answer
68 views

Indexed Drawing in OpenGL not working

I am trying to render 2 types of primitives- - points ( a Point Cloud ) - triangles ( a Mesh ) I am rendering points simply without any index arrays and they are getting rendered fine. To render ...
1
vote
1answer
90 views

OpenGL render to texture causing edge artifacts

This is my first post here so any help would be massively appreciated :) I'm using C++ with SDL and OpenGL 3.3 When rendering directly to screen I get the following result And when I render to ...
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votes
0answers
13 views

cocos2d-x simple shader usage [closed]

I want to obtain color ramp effect from this tutorial: http://www.raywenderlich.com/10862/how-to-create-cool-effects-with-custom-shaders-in-opengl-es-2-0-and-cocos2d-2-x Here is my code in cocos2d-x ...
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1answer
43 views

Having trouble with projection matrix, need help

I'm having trouble with what appears to be the projection matrix. Given a wide enough of a screen, when a cube is on the left and right most edge, the left or right wall will appear stretched to the ...
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0answers
12 views

OpenGL textures trigger error 1281 if SFML is not called

I am using SOIL to apply textures to VBOs, without textures i could change the background and display black (default color) vbos easily, but now with textures, openGL is giving an error 1281, the ...
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0answers
52 views

C++ Game Development [closed]

I want to make games.For now simple 2D games, but I don't know from where TO START. I "know" C++, but i havent worked with classes.I want to begin with GAME development and I searched in the internet ...
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1answer
42 views

Problems with texture orientation in space

I am currently drawing texture in 3D space and have some problems with it's orientation. I'd like me textures always to be oriented with front face to user. My desirable result looks like ...
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2answers
269 views

openGL Camera setup for Zoom in/out centered at point under cursor

I am trying to implement a zoom in/out navigation mode in a openGL 3dViewer. I was able to implement zoom functionality centered at screen center just by moving eye towards the center in perspective ...
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votes
0answers
20 views

Vertex buffer acting strange? [closed]

I'm having a strange problem, and I don't know what could be causing it. My current code is identical to how I've done this before. I'm trying to render a rectangle using VBO and orthographic ...
0
votes
2answers
56 views

Best way to detect if vec3 is between vec3(x) and vec3(y) in glsl

As titled I am sampling from a texture and if the color is somehow gray [vec3(.8), vec3(.9)] and an uniform is 1 I need to substitute that color with another one I am not a glsl veteran but I am ...
1
vote
1answer
134 views

Render 2 images that uses different shaders

Based on the giawa/nehe tutorials, how can I render 2 images with different shaders. I'm pretty new to OpenGl and shaders so I'm not completely sure whats happening in my code, but I think the shaders ...
-1
votes
1answer
333 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) ...
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0answers
57 views

OpenGL - Cascaded shadow mapping - Texture lookup

I'm trying to implement cascaded shadow mapping in my engine, but I'm somewhat stuck at the last step. For testing purposes I've made sure all cascades encompass my entire scene. The result is ...
2
votes
1answer
141 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 + ...
0
votes
1answer
98 views

Orthographic Projection Issue

I have a problem with my Ortho Matrix. The engine uses the perspective projection fine but for some reason the Ortho matrix is messed up. (See screenshots below). Can anyone understand what is ...
1
vote
2answers
152 views

How to detect graphics API at runtime with SDL2?

Using SDL2, is there a way to determine at runtime whether the application is using OpenGL, OpenGLES, or DirectX? EDIT: If there is a way to figure it out without using the SDL2 API, I'm willing to ...
0
votes
1answer
87 views

WebGL wrong scaling of rectangle

I'm working with this tutorial http://www.html5rocks.com/en/tutorials/webgl/webgl_transforms/ and my result is, that the rectangle moves in the direction of it's scaling values, and also scales at ...
3
votes
1answer
743 views

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
2answers
715 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
0answers
405 views

How do I mix 3D skeletal animations?

I'm trying to create a 3D-model skeletal animation system for C++/Open GL. I would like to be able to mix animations by allowing animations to only affect specific bones. My game has ride-able ...
0
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0answers
550 views

How to export all animation to Milkshape 3D using WOW Model Viewer?

I downloaded the latest wow model viewer and the milkshape 3D viewer hoping to get some WoW models for prototyping. So far I managed to export a single character with texture and a single animation. ...
0
votes
1answer
39 views

Doing a turntable camera animation on a world matrix rather than view matrix

I have a camera class that contains a 4x4 view matrix as a member variable. Most of my camera controls work fine when doing them directly on the view matrix. In an attempt to unify all of my scene ...
1
vote
1answer
150 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 ...
7
votes
1answer
142 views

Slow uniform array in shader causing FPS drop

I'm trying to use an uniform array of matrices in my compute shader. However, it's really slow. I've narrowed it down to this lines of code: uniform mat4 someMatrixArray[64]; ... vec4 result = ...
3
votes
1answer
49 views

glDrawElements vs glDrawArrays for polygons that do not reuse vertices

Is it better to use glDrawElements or glDrawArrays when not reusing vertices? There must be some difference, otherwise people would always use glDrawElements? I suppose the question could be ...
1
vote
1answer
63 views

How to implement camera pan like in Maya?

I am trying to implement camera pan like the one in Maya. I've got it almost working. The problem is that the mouse cursor is moving faster than the 3d mesh (in fact I am moving the camera but I ...
-1
votes
1answer
401 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
195 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 ...
12
votes
1answer
921 views

OpenGL - white edges on cubes

In a minecraft-like game I'm making, I get white edges on my cubes: It is much more noticeable in darker textures. The textures are being setup like this: glTexParameteri(GL_TEXTURE_2D, ...
0
votes
1answer
58 views

NiftyGUI - Text isn't rendering

I am trying to create a gui with nifty on top of lwjgl. I've already had some problems during the Nifty setup, however now Nifty is set up and running correctly but for text rendering. Here is my xml ...