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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votes
1answer
105 views

Finding pitch/yaw values from lookat vector

I have a camera class that contains a position, a pitch, and a yaw (the pitch and the yaw correspond to y and x rotation values). I want to implement a lookAt function that takes a vector and the ...
2
votes
2answers
196 views

MSAA/ CSAA / FXAA How to set the mode in OpenGL?

I'm learning OpenGL and something I am stuck with is AA. Specially when I want to turn it on and off at runtime. I know that I can set the samplecount when I create a FBO and blit it over to the final ...
2
votes
1answer
291 views

GL_DEPTH_COMPONENT vs GL_DEPTH_COMPONENT32

I googled like crazy and checked the OpenGL documentations but I couldn't find out how the precision of a depth buffer created using GL_DEPTH_COMPONENT is chosen. As far as I know the precision is ...
2
votes
1answer
100 views

OpenGL not rendering textures

i'm using OpenGL 2.1 with SDL2.0 and i'm trying to render a texture, using this steps: load the image: Image* image = new Image(); image->image = SDL_LoadBMP(path.c_str()); if ...
2
votes
1answer
110 views

Render scene depth to texture via FBO?

I'm trying to render my scene's depth via FBO and Render To Texture. I have a scene that I'm rendering to a texture, then render that texture to a fullscreen quad in a second pass using a fragment ...
2
votes
1answer
78 views

OpenGL vertex data per index

Usually, vertex data is assigned to a particular vertex, like this: [data] [vertices] [1.31] -> [1, 13, 5] [84.3] -> [5, 8, 12] [.095] -> [8, 3, 10] Then, you would typically have an ...
2
votes
1answer
304 views

OpenGL picking performance: ray casting vs. color picking

I am curious of how the performance of color picking compares to ray casting. I am looking at the scenario when the mouse is clicked which means only then the scene is rendered in a backbuffer for ...
2
votes
1answer
949 views

OpenGL VBO and VAO Confusion

I would like to present here my Question about VBOs and VAOs. Basically from what i understand you can have different VAOs each of which can contain up to several VBOs , and by binding to the VAO's ID ...
2
votes
1answer
514 views

Why encode floats in RGBA?

Working on some effects that require depth (Z) data in Unity, I saw that these use a method to store the depth data encoded in the RGBA channels of a regular texture. half4 frag(v2f i) : SV_Target { ...
2
votes
1answer
128 views

How can I deal with vertex precision errors between terrain chunks?

I am using OpenGL to render the following scene, using vertex data from one of the map files of a popular MMORPG. The data is chunked and the pictured scene is made up of 256 (16x16) chunks. However ...
2
votes
1answer
1k views

2D graphic over 3D perspective projection

To draw a 2D HUD (just a simple trianlge, for now) over 3D graphics in OpenGL I : draw all 3D objects, then call glDisable(GL_DEPTH_TEST) before drawing 2D HUD draw 2D triangle call ...
2
votes
1answer
443 views

How to improve Batch Rendering to work with 3D skeletal animation data

I've implemented a batch rendering technique that is described in detail here: http://www.gamedev.net/page/resources/_/technical/opengl/opengl-batch-rendering-r3900 I'd like to extend it now to ...
2
votes
1answer
264 views

How can I implement a camera like the one in RotMG?

RotMG, an MMO top-down shooter, takes on a unique 2d-3d style, and has an intriguing camera; The game is obviously 3d, not simply isometric, and if you play the game and turn on camera rotation you ...
2
votes
1answer
802 views

Architecture to draw many different objects in OpenGL

I have some objects that I want to draw. I am not sure how I can create my architecture in a way where I can draw everything as fast as possible. As example: class MyObject { float[] vertices; ...
2
votes
1answer
555 views

OpenGL ES draw pre-rendered background onto depth buffer

I want to create a scene with 2D pre-rendered background and 3D models for characters (like those classic Final fantasy games). For the background, I have 2 textures: one to be displayed, with ...
2
votes
1answer
71 views

How to know when graphics driver or card changes

I'm about to start work on implementing GLSL binary shader compilation and I was curious how to handle the cases when the shaders need to be recompiled, such as when the driver (or perhaps even the ...
2
votes
1answer
61 views

Rendering a mesh in image viewport

I have a mesh made of nearly half to a one million vertices. I also have some 6-DoF camera poses around this mesh. At these poses I'd like to find out which of the 3D points of this mesh get projected ...
2
votes
2answers
400 views

Water silhouette shader using GLSL

I have this problem to solve using Cocos2d-x 3.x: In my game there is water represented by rectangle texture, modified by the code on the go. I also have a character moving around, rotating etc. I ...
2
votes
1answer
344 views

GLFW mouselook under OSX

I'm continuing to port an OpenGL app from Visual Studio 2012 to XCode 5. The only major issue I'm having is mouselook. It "doesn't work" under OSX (Mavericks). Here's the (pseudocode): ...
2
votes
1answer
237 views

Additive blending problems

I'm trying to get the blend of two images to work without luck. I have a render target on which I have an object, then I want to render again the same object in same position but with different ...
2
votes
1answer
200 views

What types of matrices are needed for game and graphics programming?

I am writing a 3D math library for general game development and want to know what type of Matrix classes I should include. Is just a 4x4 matrix enough, or must I provide 3x4 and dedicated rotational ...
2
votes
1answer
1k views

Reflection and shadows in OpenGL

I'd like to implement shadows and reflective surfaces in my OpenGL app. I already have ideas which I will provide below. But I would like to ask someone more experienced than me before I put too much ...
2
votes
1answer
521 views

How to create a regular grid of triangles correctly?

I am trying to create an terrain using opentk/opengl. I have a problem with the VBO/IBO. I think a picture of the problem is the best way to show it: I dont understand why the last triangle of a ...
2
votes
2answers
1k views

3D position to UV coordinates in fragment shader

I am interested in converting an arbitrary 3D position computed at run time in the fragment shader to its corresponding UV coordinates. Notice that the 3D position I am interested in is NOT a 3D ...
2
votes
1answer
2k views

Why do I get “function not supported” exceptions for OpenGL 3.2 functions using LWJGL?

I am currently having an issue trying to initialize a frame buffer using LWJGL. When I try to call GL32.glFramebufferTexture(int, int, int, int) it throws a "Function is not supported" error. I have ...
2
votes
1answer
160 views

Does Direct3D have hardware-dependant extensions like OpenGL?

I am not familiar with Direct3D and I want to know if it has hardware and vendor dependant functions like the extensions in OpenGL? A program written by a friend fails on certain computers while it ...
2
votes
1answer
515 views

Efficient way of loading wavefront models in openGL game

In my game, a RTS game, the units are all wavefront obj. all their animation frames are each seperate wavefront obj file. ie. without any skeletal animation; fully rigid models. So when many units are ...
2
votes
2answers
512 views

Batching and Z-order with Alpha blending in a 3D world

I'm working on a game in a 3D world with 2D sprites only (like Don't Starve game). (OpenGL ES2 with C++) Currently, I'm ordering elements back to front before drawing them without batch (so 1 element ...
2
votes
1answer
968 views

Assimp renders a partial amount of vertices

I'm building a 3D game, and i'm trying to load some assets with the nice Assimp library. The model should look like the one in the first picture, but instead, it takes the form of some kind of ...
2
votes
1answer
408 views

Do glColorMask and glDrawBuffer accomplish the same thing?

I'm doing a shadowmap pass (only storing depth values) so I set glDrawBuffer(GL_NONE) to disable color writing for the moment. Yet, I see some tutorials also do glColorMask(GL_FALSE, GL_FALSE, ...
2
votes
1answer
684 views

How can I render a single object that uses multiple textures?

I'm looking for a technique to render an object with multiple texture sources. One texture is static, the other is generated dynamically (it's a render target). For example, say I was rendering a TV. ...
2
votes
3answers
731 views

How can I apply a mesh distortion to walls like in Dungeon Keeper 2?

In Dungeon Keeper 2, the walls of the dungeon have different random shapes depending on its state (freshly dug or reinforced, and so on). They look like they are cubes of 3x3 vertices that have a ...
2
votes
1answer
678 views

Black or White Border/Shadow around PNGs in SDL/OPENGL

having the same issue as this: Why do my sprites have a dark shadow/line/frame surrounding the texture? however, when I do the fix suggested there (changing GL_SRC_ALPHA to GL_ONE) it just replaces ...
2
votes
2answers
3k 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 ...
2
votes
1answer
2k views

Uncharted 2 tone mapping and an eye adaptation

I found an example of uncharted 2 tone mapping on this site. Here is the code: float A = 0.15; float B = 0.50; float C = 0.10; float D = 0.20; float E = 0.02; float F = 0.30; float W = 11.2; float3 ...
2
votes
2answers
351 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 ...
2
votes
1answer
104 views

Expandable player boundaries

I'm trying to plan how to implement non-fixed boundaries so the player can expand their controlled territory without using a tiled based system. Each pixel can be fought over for who controls it. I ...
2
votes
1answer
773 views

What happens when a texture is too large for a device

The question is two fold: What happens on a device when a texture is too large for it to handle? Will it crash or simply downsize it? In Unity if I use texture atlases of size 4k and then set ...
2
votes
2answers
217 views

.md5mesh normals are not smooth

I'm currently working on a project that requires me to load .md5mesh format and draw it. Following this link I've managed to load the mesh into the engine successfully, but a problem arises when ...
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

Heightmap and Textures

Im trying to find the "best way" to apply a texture to a heightmap with opengl 3.x. Its really hard to find something on google because tutorials are olds and they're all using different methods, im ...
2
votes
1answer
161 views

How to obtain touch events from a GL Viewport, not the whole screen?

Background I'm implementing viewport resizing in order for my game to maintain the same display ratio on all devices. However, I've found an issue with getting touch events. Basically, if my ...
2
votes
1answer
188 views

Manual GLU.gluUnproject

Before I used GLU.gluUnproject to calculate my picking ray in my OpenGL game. Recently I switched to my own calculated matrices, and now I can forget the gluUnproject. How can I calculate the picking ...
2
votes
2answers
340 views

How scanline rendering finds an intersection with an object

I'm a newbie with graphics and after I read many articles on the web I still don't understand how in rasterizing from a pixel coordinate like (0;0) on the screen the intersection with an object (let's ...
2
votes
1answer
557 views

Translating Viewmatrix is inverted, why?

So I've defined a Projectionmatrix, Viewmatrix and a Modelmatrix using OpenGL (LWJGL). But when I translate my Viewmatrix to +X it moves my object to the right (hence my camera is moving to the ...
2
votes
1answer
494 views

gbuffer - how to store an integer data

In a gbuffer I store a diffuse color in following texture: glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL); I want to store an integer data which ...
2
votes
1answer
1k views

HDR / Tone Mapping - choosing parameters

I implement HDR in my graphics engine (deferred rendering) based on this document: link I save a luminance in a texture (RGBA16F) this way: const float delta = 1e-6; vec3 color = texture(texture0, ...
2
votes
1answer
2k views

glsl 150 struct in uniform buffer object

Can I do this in opengl 3.2 / glsl 150? glsl shader: struct LightSource { vec4 ambient; vec4 diffuse; vec4 specular; vec4 position; vec4 direction; }; ... layout(std140) uniform ...
2
votes
1answer
375 views

How to transform a shadow map to camera view?

I'm making a rendering engine as a hobby to learn more about 3D. I have a deferred renderer with the G-buffer (color, normal and depth). I also have a lighting controller that uses only spotlights at ...
2
votes
1answer
399 views

Not repeating background in platformer [closed]

I need to make not repeating background for platformer. I can't find any description of implementation and I developed algorithm but I'm not sure that it's right. I can't load one big texture per ...