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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2
votes
2answers
215 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
613 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
964 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
156 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
183 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
308 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
496 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
459 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
361 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
382 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 ...
2
votes
1answer
3k views

Can I mix OpenGL and swing?

I'm working on a small game library for me and some people I know that just handles the window and nothing special that we weren't gonna use. I know how to use OpenGL and stuff I just don't like ...
2
votes
2answers
1k views

Raycasting mouse coordinates to rotated object?

I am trying to cast a ray from my mouse to a plane at a specified position with a known width and length and height. I know that you can use the NDC (Normalized Device Coordinates) to cast ray but I ...
2
votes
2answers
2k views

Quaternion based rotation and pivot position

I can't figure out how to perform matrix rotation using Quaternion while taking into account pivot position in OpenGL.What I am currently getting is rotation of the object around some point in the ...
2
votes
1answer
2k views

Can't use SFML sprite drawing and OpenGL rendering at the same time

I'm using some SFML built in functions to draw sprites and text as an overlay on top of some OpenGL rending in an SFML RenderWindow. The opengl rendering appears fine until I add the code to draw the ...
2
votes
1answer
133 views

Uniform not being applied to proper mesh [closed]

Ok, I got some code, and you select blocks on a grid. The selection works. I can modify the blocks to be raised when selected and the correct one shows. I set a color which I use in the shader. ...
2
votes
1answer
401 views

OpenGL 3+ Range Picking

How do I perform range picking in the latest OpenGL version? By range picking I mean selecting all objects which are picked using a selection rectangle, like in an RTS game. For single object picking ...
2
votes
1answer
847 views

OpenGL: Move camera regardless of rotation

For a 2D board game I'd like to move and rotate an orthogonal camera in coordinates given in a reference system (window space), but simply can't get it to work. The idea is that the user can drag the ...
2
votes
1answer
346 views

Is there any reason not to save skinning animation data in texture?

I have thought about saving animation data in texture. I think I can save shader parameter setting and interpolation cost in CPU, and also enable animated instancing. But I couldn't find no text ...
2
votes
1answer
533 views

Finding a suitable axis-angle to avoid gimbal lock

In OpenGL the camera faces the -z axis with the +y axis pointing up. I am using quaternions to represent the orientation of my objects (which works well) and am trying to do the same for the camera. I ...
2
votes
1answer
1k views

Procedural terrain using 3D noise

I'm coding a procedural terrain generation based on this article from GPU Gems 1. But using CPU (not GPU). I'm stuck at generating the procedural terrain. I just can't figure out how make a 3D ...
2
votes
1answer
333 views

Geometry shader questions?

I had some questions on geometry shaders. Do directx geometry shaders offer anything over the opengl ones? What advantages does the official geometry shader implementation on opengl 3.2 have over ...
2
votes
3answers
3k views

C# 2D Game Library?

I'm looking for a C# 2D game library based on something like OpenTK which wraps OpenGL for C# Basically something like Slick2D (2D game library for Java) which is based on LWJGL which is an OpenGL ...
2
votes
1answer
252 views

Rotation going wrong

I'm calculating matrices by hand. Translations are fine: void Translate (float x, float y, float z, float[4][4] m) { Identity (m); m[3][0] = x; m[3][1] = y; m[3][2] = z; } If ...
2
votes
1answer
2k views

Opengl drawing a section of a texture stretched over a quad

Current Situation I have a spritesheet loaded in for a texture when drawing the specific portions of the sheet that I'd like to have on my quads I do some simple math to get their location on the ...
2
votes
3answers
1k views

Can't use the hardware scissor any more, should I use the stencil buffer or manually clip sprites?

I wrote a simple UI system for my game. There is a clip flag on my widgets that you can use to tell a widget to clip any children that try to draw outside their parent's box (for scrollboxes for ...
2
votes
1answer
369 views

Update single entry in GLSL array

I have an array in my vertex shader like this: uniform mat4 MeshTransforms[20]; At the moment I'm just updating the entire array of matrices like so: int meshTransforms = ...
2
votes
1answer
2k views

Bullet Physics Terrain

Im trying to Load an RGB image (.BMP) into bullet's btHeightfieldTerrainShape Im using a loader that creates a openGL height map, it stores the data in a vector float, but I cant get the ...
2
votes
2answers
4k views

How to use OpenGL's glUseProgram?

While in the rendering loop, is it OK to call glUseProgram? Does it have a big overhead? I'm planing to use a program for each different material in the scene. I'm a real beginner with OpenGL and I'm ...
2
votes
2answers
2k views

Why is OpenGL using 100% CPU shortly after start up when wglSwapIntervalEXT is enabled?

I have a game which uses SFML, which in turn uses OpenGL. When I run the game, it will use 100% CPU for (usually) about 24 seconds, and then immediately falls down to normal usage. I can't figure out ...
2
votes
2answers
2k views

What is an efficient way to deal with large, scrolling background images?

In my mobile game you basically you just fly up (infinite height) and collect stars. I have many quite large background images, scaled down so that their width is the same as the device width. Then ...
2
votes
2answers
568 views

How to convert a Maya object to a VBO?

I'm currently trying to teach myself OpenGL... and quickly discovering that the Immediate Mode taught in old OpenGL tutorials is basically obsolete... which leads me to VBO's... which I kind of get ...
2
votes
1answer
2k views

SDL (or OpenGL), HTML5, Gecko and vector movies

I'm writing a platform game which uses SDL for the main graphics code. There is a chance that I may be using OpenGL for the rendering at a later stage, so answers could relate to either. I'm needing ...
2
votes
1answer
608 views

Writing the correct value in the depth buffer when using ray-casting

I am doing a ray-casting in a 3d texture until I hit a correct value. I am doing the ray-casting in a cube and the cube corners are already in world coordinates so I don't have to multiply the ...
2
votes
2answers
1k views

Using multiple indexes with buffer objects in OpenTK

I've got multiple buffers in OpenGL holding data on position, normals and texcoords. I also have an equal number of buffers holding distinct index data for each of those buffers. I quite like this ...
2
votes
2answers
203 views

Help computing visibility in old 3d game format

I am trying to compute visibility in an old 3d file format. I am using a BSP tree have finally gotten everything built and traversable. Now I don't have any sort of PVS, potentially visible set to ...
2
votes
1answer
3k views

How to properly repeat a texture on a quad in OpenGL?

I'm drawing a quad and binding a texture to this quad like this: #define TERRAIN_WIDTH 2000 #define TERRAIN_LENGTH 2000 #define TERRAIN_WIDTH_2 (TERRAIN_WIDTH / 2) #define ...
2
votes
1answer
2k views

Restoring projection matrix

I am learning to use FBOs and one of the things that I need to do when rendering something onto user defined FBO, I have to setup the projection, modelview and viewport for it. Once I am done ...
2
votes
1answer
4k views

Computing a normal matrix in conjunction with gluLookAt

I have a hand-rolled camera class that converts yaw, pitch, and roll angles into a forward, side, and up vector suitable for calling gluLookAt. Using this camera class I can modify the model-view ...
2
votes
1answer
3k views

Using gluLookAt to move camera in 2D iPhone game?

I'm trying to use gluLookAt to move the camera in my iPhone game, but every time I've tried to use gluLookAt my screen just goes "blank" ( grey in this case ) I'm trying to render a simple triangle ...
2
votes
1answer
57 views

How to store renderer vertex / index data in scene graph objects?

I have a SceneNode class which contains a Mesh instance. The Mesh class stores client side information such as vertex and index arrays (before they're uploaded to the GPU). I also have an abstracted ...
2
votes
1answer
78 views

How to blur image using glsl shader without squares?

I want to blur image with Gaussian blur algorithm. And I use the following shaders: Vertex shader attribute vec4 position; attribute vec4 inputTextureCoordinate; const int GAUSSIAN_SAMPLES = 9; ...
2
votes
1answer
40 views

Shaders wont bind to the uniform block

I'm having an issue with interface block binding. Example shader: const char* vertexShader = "#version 330 core\n" "uniform globalMatrices" "{" " mat4 ...
2
votes
1answer
40 views

OpenGL - Bind Buffer Arrays question

So this is probably a simple question: But how come sometimes I see it like this: GLuint vbuffer; glGenBuffers(1, &vbuffer); glBindBuffer(GL_ARRAY_BUFFER, vbuffer); but when done in multiples: ...
2
votes
1answer
47 views

OpenGL pitching problem

I've been trying to implement several camera movements for my application. So far yawing, rolling, strafing, walking has been working properly, but I can't get my pitching to work properly. If I ...
2
votes
1answer
102 views

How can I recover polygons and normal maps from compiled games through emulation of D3D or OpenGL?

I am trying to generate labeled training data for an artificial visual cortex to learn on. I'm looking for a tool that will, instead of rendering the scene at each pixel just give me the pre-rendered ...
2
votes
1answer
51 views

Check if .dds texture is gamma-corrected

How can I check if .dds texture is gamma-corrected? It seems to be gamma-corrected since after manual gamma correction in fragment shader image is too bright. But I wanted to be sure.
2
votes
1answer
113 views

How to attach a framebuffer to a whole cube map from a GL_TEXTURE_CUBE_MAP_ARRAY?

I'm trying to make shadow cube maps in an array. I want to draw each shadow map with a single pass using a geometry shader, which I read about here: ...
2
votes
1answer
93 views

Tiled deferred rendering light culling

I'm trying to implement tile based light culling in opengl using a compute shader. I am using this as a guide. The lighting calculations work fine but the point light culling doesn't seem to work any ...