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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5
votes
1answer
420 views

Animation of moving circle by square's outer surface

I want to make this animation in OpenGL, here I attached a simple gif how I want it to looks like: Main problem is that I can not figure out how to move by corner - circle should smoothly move by ...
0
votes
3answers
171 views

directional lightning

I have managed to get a point light working, but I am facing problem with directional lightning. Fragment shader uniform vec4 lightColour ; uniform vec3 lightPos ; uniform float lightRadius ; ...
1
vote
1answer
798 views

OpenGL Texture loaded but wont draw on Bind

I wrote my entire Texture loader by hand. I'm not using any Libraries. From what I gather the loading part is done correctly and stored in the texture class: Texture* TGATextureLoader::create(const ...
1
vote
1answer
177 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 ...
2
votes
1answer
971 views

How to select a vertex by mouse clicking in OpenGL?

I'm programming a simple graph game and so far I'm still doing a few tests in OpenGL. Right now, let's say I defined a GL_POINT with the glVertex2f(20.0f, 0.0f). I have this function to calculate the ...
3
votes
2answers
1k views

Identity matrix. Confusion. What does it really do

I understand identity matrix is like multiplying to 1. But i can't really understand why would you multiply an a matrix that will only result to the same. Also im messing up with an OpenGL code and ...
0
votes
1answer
1k views

How to load and draw this *.obj correctly?

I have a loader class for *.obj files (called GLModel) which has 2 main methods - public GLModel(BufferedReader ref, boolean centerit, GL gl,Texture texture) which use for *.obj load , and ...
1
vote
2answers
327 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 ...
0
votes
1answer
104 views

How can I animate a portion of the textures on a model?

I have a model to which I have attached multiple textures. Both textures are currently static, but if I want to move (or slide) the texture which is on the top (in UV space), is that possible? Maybe ...
2
votes
1answer
369 views

How does the fragment shader get data from the vertex shader?

How can any interactions between these two shaders work? I mean the vertex shader sends a vertex's color to the fragment shader, but that's only one fragment, what about all the other ones between the ...
1
vote
1answer
561 views

What is the difference between shader uniforms and attributes in OpenGL?

I don't fully understand the differences between uniforms and attributes. To be honest, I probably haven't even used attributes. Can uniforms change for each vertex? I mean to calculate the vertex's ...
2
votes
1answer
241 views

Are ambient, diffuse and specular light or material properties?

Are ambient, diffuse and specular properties of light or material? I am doing ray casting in OpenGL, I've managed to create lit sphere using formula I = L Ka + L Kd (n . l) + L Ks (r . v)^n but I ...
0
votes
2answers
431 views

Batching elements

I don't understand exactly how batching works. What I have understood: Batching is useful to regroup similar elements together and draw them in one draw call (performance++), currently drawing an ...
0
votes
1answer
84 views

Why, after calling SetVideoMode as in the following, does nothing appear on my screen?

I am trying to create an application that will need to use double buffering (for purpose of vsync). I am using SDL.NET. From what I understood, in order to have double buffering, I have to ...
-1
votes
1answer
728 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 ...
3
votes
1answer
178 views

Spliting up VAOs?

At the moment I have one vertex/fragment shader, but I am looking to add another shader program to deal with shadow maps. In my "final" shader I have VAO which define positions, normals, texcoords, ...
1
vote
1answer
240 views

How can I extract the RGB color data from a TGA image?

I am working in OpenGL, and I am trying to create terrains using height maps. I am using my own functions to load a TGA image, and in order to pass data to heightmap vertex shader I need to retrieve ...
0
votes
1answer
560 views

What is Opengl ES ? What is gl and GLES20 mean?

I am new in opengl. I saw tutorial some have gl at the beginning and some have GLES20 at the beginner and some has GL10. What are the differences? Is GLES20 mean opengl es2 whereas GL10 mean version ...
8
votes
1answer
976 views

what is world space and eye space in game development?

I'm reading a book about 3D stuff and OpenGL. The book often talks about world space and eye space. What exactly is the "world space?" Does the "eye space" mean the projection?
0
votes
1answer
395 views

fragment shader directional light positioning with camera

Im trying to set up directional lighting in the fragment shader. So the direction of my light moves with the camera position. #version 150 core uniform sampler2D diffuseTex; ...
4
votes
2answers
249 views

Shadowmap first phase and shaders

I am using OpenGL 3.3 and am tryin to implement shadow mapping using cube maps. I have a framebuffer with a depth attachment and a cube map texture. My question is how to design the shaders for the ...
3
votes
1answer
628 views

Aquire disassembly of shader code

Is there a way to get the disassembly that your driver generates when compiling a shader? I noticed that you can get an accidental disassembly dump if you go over the maximum thread group size ...
0
votes
1answer
1k views

Quaternion LookAt for camera

I am using the following code to rotate entities to look at points. glm::vec3 forwardVector = glm::normalize(point - position); float dot = glm::dot(glm::vec3(0.0f, 0.0f, 1.0f), forwardVector); ...
3
votes
2answers
531 views

GLM Velocity Vectors - Basic Maths to Simulate Steering

UPDATE - Code updated below but still need help adjusting my math. I have a cube rendered on the screen which represents a car (or similar). Using Projection/Model matrices and Glm I am able to ...
5
votes
1answer
271 views

Spherical harmonics lighting interpolation

I want to use hardware filtering to smooth out colors in texels of a texture when I'm accessing texels at coordinates that are not directly at the center of the texel, the catch being that the texels ...
2
votes
1answer
97 views

Accessing 3D texture data without normalized coordinates directly, but with filtering

texelFetch() exists to access texture data with texture coordinates in "image dimensions", but texelFetch skips filtering. In case of 2D textures, it's possible to use a rectangle texture sampler to ...
2
votes
0answers
1k views

Arcball 3D camera

I have checked multiple threads before posting, but i havent been able to figure this one out. Ok so i have been following this tutorial, but im not using glm, ive been implementing everything up ...
0
votes
1answer
139 views

Rotation and translation like in GTA 1 OpenGL

Okay, so I have a figure in XZ plain. I want to move it forward/backward and rotate at it's own Y axis, then move forward again in the rotation's direction, like the character in GTA 1. Code so far: ...
1
vote
1answer
247 views

How many VBOs should I use and should I keep a copy of their data?

Firstofall, I am sorry if my question is to broad. I am developing a tile based game and switched from those gl.Begin calls to using VBOs. This is kind of working allready, I managed to render a ...
1
vote
1answer
82 views

Models not rendering when far away

I am making a game where objects are represented by colored cubes. I have files that mark the location and rotation of the cubes. I've been using Processing's 3D library and the cubes disappear within ...
0
votes
1answer
110 views

Lwjgl or opengl double pixels

I'm working in java with LWJGL and trying to double all my pixels. I'm trying to draw in an area of 800x450 and then stretch all the frame image to the complete 1600x900 pixels without them getting ...
0
votes
1answer
541 views

c++ most used libraries [closed]

I'm trying to find out whether or not I want to switch from Java to c++ for my OpenGL game programming. I now have setup a test project in VS 11 professional, with GLUT. I created my windows with ...
0
votes
1answer
155 views

Setting up cube map texture parameters in OpenGL

I see alot of tutorials and sources use the following code snippet when defining each face of a cube map: for (i = 0; i < 6; i++) glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, ...
0
votes
2answers
145 views

Accesing depth buffer from shader

I read this presentation and on 6th slide I found that is not need to use multiple render targets and depth can be taken directly from depth buffer. From which version of DirectX or OpenGL can be ...
2
votes
1answer
682 views

RTS Voxel Engine using LWJGL - Textures glitching

I'm currently working on an RTS game engine using voxels. I have implemented a basic chunk manager using an Octree of Octrees which contains my voxels (simple square blocks, as in Minecraft). I'm ...
0
votes
3answers
249 views

OpenGL camera moves faster than player

I have a side scroller game made in OpenGL, and I'm trying to center the player in the viewport when he moves. I know how to do it: cameraX = Width / 2 / TileSize - playerPosX cameraY = Height / 2 / ...
0
votes
2answers
222 views

Camera movement with slerp

I have 3 spots, I would like to move my camera to using slerp. Just As seen in the image below. My question is how I can connect my camera to the first spot? I should be able to move between other ...
1
vote
1answer
341 views

Infinite terrain shadows

I'm creating an infinite terrain engine, which generates the terrain either with fractals or noise. How can I make dynamic shadows for the sun on this terrain, if I don't know in advance what will be ...
0
votes
1answer
582 views

LWJGL - Continuous key press event without delay

I am checking for key presses and then based on the keys pressed I am moving a square around the screen. I am setting booleans for the keys WASD. But , Whenever I try to keep the key down , it takes a ...
1
vote
3answers
875 views

OpenGL position from depth is wrong

My engine is currently implemented using a deferred rendering technique, and today I decided to change it up a bit. First I was storing 5 textures as so: DEPTH24_STENCIL8 - Depth and stencil ...
1
vote
2answers
2k views

In GLSL is it possible to offset vertices based on height map colour?

I am attempting to generate some terrain based upon a heightmap. I have generated a 32 x 32 grid and a corresponding height map -> In my vertex shader I am trying to offset the position of the Y ...
1
vote
1answer
407 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 ...
1
vote
3answers
793 views

Android : glowing/pulsing line/triangle

I would like to create a simple Android app using Opengl ES 2.0 that is showing a simple shape (like line or triangle) that is glowing and pulsing like Nexus X logo in this video : ...
0
votes
2answers
223 views

Normal map applied as diffuse textures looks wrong

Diffuse textures works fine, but I am having problem with normal maps, so I thought I'd tried to apply the normal maps as the diffuse map in my fragment shader so I could see everything is OK. I ...
2
votes
1answer
289 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
331 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
474 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
379 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
211 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
458 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 ...