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
357 views

Fog shader camera problem

I have some difficulties with my vertex-fragment fog shader in Unity. I have a good visual result but the problem is that the gradient is based on the camera's position, it moves as the camera moves. ...
-1
votes
1answer
121 views

Ray picking gives inversed results

I'm trying to do a simple ray picking implementation to allow a user to select a cell in a grid rendered in 3D. I'm almost there, but I've ran into an issue which I can't seem to solve. Consider the ...
-3
votes
1answer
269 views

Opentk: Move Bones model 3d [closed]

I have a model in 3ds max and have exported to obj file using tutorials and I managed to load my model and apply a texture. My problem is that I have to move a part of this model and to move while ...
0
votes
0answers
319 views

GLSL gl_ModelViewMatrix breaks my code?

So I have the following shaders which work (to the extent that they are completed anyway). //Vertex Shader uniform float offset; void main() { gl_TexCoord[0].t = gl_MultiTexCoord0.t; ...
0
votes
1answer
507 views

Simplest way to render image over top of another with another image used as mask in OpenGL?

The effect I'm looking for is to have a single large background image that is always visible (at full alpha) and then show a second image (what I call a light map or specular map) that is partially ...
3
votes
1answer
255 views

small independent game development on a virtual machine

I've been learning about OpenGL and SFML with c++ now for about 6-8 months, and would like to work on a small little personal game to put some of my skills to the test. Now I want to kill two birds ...
1
vote
1answer
124 views

OpenGL light not shining quad

I've constructed a scene using OpenGL/GLUT with a spot light but I'm getting troubles with light shining some of the walls what is going on and how to solve?
0
votes
1answer
192 views

Shader program compiles fine on Ati, fails on other vendors

Got a real annoying problem here. My shader program compiles fine on my Ati Radeon HD card, but on Nvidia and Intel it failes to compile. Vertex shader: #version 120 attribute vec3 in_position; ...
7
votes
3answers
3k views

How do I implement occluded lighting in a block-based 2D game?

I want to have 2D lighting that can be blocked by in-game objects. My game has a top-down view and all game objects are described by rectangles. Let's say I have a 10x10 world and I place a light at ...
1
vote
2answers
2k views

What is the best method to update shader uniforms?

What is the most accepted way for keeping a shader's matrices up to date, and why? For example, at the moment I have a Shader class that stores the handles to the GLSL shader program & uniforms. ...
1
vote
1answer
223 views

Why does my blur shader implementation produce this strange result?

I tried to implement the blur shader shown here. Instead of having a simple 2D texture I use Unity's GrabPass function to capture what's behind the plane to have a transparent effect. Then I apply ...
3
votes
2answers
383 views

How to subdivide a quad?

I'm working with OpenGL and I'm importing from a file coordinates for quads in the following format: 0.0 1.0 0.0 //normal vector 20.0 -5.0 20.0 10.0 10.0 //x y z u v 20.0 -5.0 -20.0 10.0 0.0 ...
2
votes
1answer
241 views

GLSL Multiple Uniform Structs

I'm developing a lighting system for my voxel game, and I have to send multiple (alot, say up to 200) lights to my shader program. Those lights contain the following data: Position (vec3) Color ...
6
votes
1answer
657 views

Do I need to rewrite my HLSL shaders when porting from XNA to MonoGame?

I'm looking at porting an XNA project I have to monogame, but I have a fair number of HLSL shaders. It seems that Monogame for PC uses OpenGL as the rendering backend, and I'd rather not have to ...
2
votes
1answer
177 views

How to get independent from GLEW dll file

I'm literally an absolute noob in GL. I just wrote my first GLEW piece of code yesterday: #include <stdio.h> #include <stdlib.h> #include <GL/glew.h> #include <GL/glfw.h> int ...
6
votes
1answer
295 views

How to find the bottleneck in a typical OpenGL game?

I am working on a little game engine. All major features are implemented yet, despite game logic which I assume not to be such a computational effort. The framerate is at least around 40 FPS, most of ...
2
votes
1answer
670 views

Simple Optimized Blur Shader

I have a vertex-fragment shader that use the Unity3D GrabPass functionality (it grabs the screen). And I apply my GrabPass to have a transparent effect. GrabPass { "_GrabTex" } sampler2D ...
4
votes
1answer
403 views

Making a game “resize-safe”

It's one thing to get the graphics aligned perfectly, it's another to do this for every single resolution and not take too much time and/or make the code unreadable due to size. Games like Battlefield ...
5
votes
1answer
2k views

GLSL Light (Attenuation, Color and intensity) formula

I'm implementing point lights in my Voxel engine, and I'm really struggling to get a good flow of light, from 100% near the light source to 0% at the light radius. I have 5 arguments for the ...
3
votes
2answers
155 views

Opengl shader questions

I'm currently building a shader that takes a 2D texture sampler and uses UV coordinates to map it. This works fine for all textured objects. However, I'm having a bit of a problem as I'm trying to ...
2
votes
1answer
139 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 ...
0
votes
1answer
264 views

Drawing a HUD above 3D with shaders in GL

In the old days you would just do glOrtho in Projection, reset Modelview-Matrix and draw in [-1,1],[-1,1],0. But now-a-days we have shaders and I wanted to avoid the use of matrices. My code so far: ...
5
votes
2answers
274 views

Include deprecated OpenGl “immediate mode” context in OpenGl 4?

I'm working on an app that uses immediate mode in all of it's draw routines and I'd like to keep those functions intact when updating our graphics drivers to OpenGl 4. My intention is to get the app ...
1
vote
2answers
939 views

Calculate object coordinates from window coordinates using inverse projection matrix

What I am trying to to is placing 3D Objects (A Sphere) in the world when I click there. I am using a perspective projection so the first step after calculating the canonical clip coordinates from ...
7
votes
1answer
2k views

Most efficient way to draw vertex with OpenGL

I am writing an OpenGL 3D game. There will be tons of triangles for terrain and objects in use. I am studying from the OpenGL official guide and the first presented method is to call a function ...
-1
votes
1answer
56 views

Reverting the view SDL

So in my SDL application, which I setup for OpenGL, if I were to do the following code: glBegin(GL_QUADS); glVertex2i(0, 0); glVertex2i(50, 0); glVertex2i(50, 50); glVertex2i(0, 50); glEnd(); The ...
6
votes
1answer
410 views

Texture coordinate discontinuity with mipmaps creates seams

I just started learning openGL and I am getting this artifact when texturing a sphere with mipmaps. Basically when the fragment samples the edge of my texture, it detects the discontinuity (say from 1 ...
1
vote
1answer
108 views

2D Platform character getting “unaligned” with the map

I'm trying to make a 2D Platform game and so far I can have my character moving around in a tiled map and collisions are working too. So far so good. The problem I'm having is that the character can ...
2
votes
3answers
2k views

How do I position a 2D camera in OpenGL?

I can't understand how the camera is working. It's a 2D game, so I'm displaying a game map from (0, 0, 0) to (mapSizeX, 0, mapSizeY). I'm initializing the camera as follow : Camera::Camera(void) : ...
-1
votes
1answer
162 views

OpenGL shader problem

So, I've been working on this game engine for a while now, and just the other day my friend tried running the program and his output doesn't match my output... My Program Output: His Program ...
6
votes
0answers
176 views

OpenGL profiling with AMD PerfStudio 2 [closed]

I'm rendering just a really small amount of polygons for my UI but however I still tried to increase the FPS. In the end I removed redundant calls which increased the FPS. I really don't want to lose ...
-2
votes
1answer
346 views

How to start graphics programming? [closed]

I'm trying to find a complete guide for OpenGL programming but all i can found is some blogs with non-finished lessons and old books. I don't want to just make a game, i want to develop my own game ...
2
votes
1answer
1k views

OpenGL VBO - load a normals index

Okay I have the following code that works correctly. It loads a vertex array, a normal array and a vertex index array then draws them with some simple light shading. To load the buffers: //Load ...
1
vote
1answer
185 views

Drawing models and their bounding boxes using two different shaders?

I have a bunch of 3d models I want to draw and also for some of them I want to draw bounding boxes. Calculating the boundnig boxes is no problem, but I'm not sure as to what is the best approach to ...
8
votes
1answer
572 views

2D Water top surface profile

I am trying to create the effect of the water surface thickness with a vertex-fragment shader. I am in a 3D game environment but It's a scroll view so a "2D" view. Here is a good tutorial of creating ...
4
votes
1answer
288 views

Library for generating primitive shapes? [closed]

I'm looking for a library to generate the data for primitive shapes for opengl. I have lights, and I simply wants to draw a sphere to represent the lights transform in the world I do not want a ...
0
votes
1answer
1k views

How can I implement infinite scrolling by scrolling the background's texture, not the quad? [duplicate]

I'm writing a 2D platformer game on Java with LWJGL. I'm doing this just for the sake of learning and not the result itself, so when I decided to implement scrolling I did it two ways I could invent ...
5
votes
2answers
859 views

Is the “impossible object” possible in computer graphics?

This may be a silly question but I want to know the answer to it. I saw this thing called the "impossible object", while they're many different images of this online, it's suppost to be impossible ...
-3
votes
1answer
388 views

Is Microsoft killing OpenGL? [closed]

In an article I've read that Microsoft signed GDI/GDI+ as deprecated. I was a bit frightened, I won't be able to use OpenGL in future versions of Windows. Since you need GDI ( more likely the Device ...
0
votes
0answers
125 views

Depth Test not working properly on Nvidia

So, I send a Development Test of my in-dev game to some friends, and they found out that the Depth Test in OpenGL does not work on Nvidia. I use my own matrices and sent them to the shader, and at ...
3
votes
2answers
4k views

OpenGL - Understanding the relationship between Model, View and World Matrix

I am having a bit of trouble understanding how these matrixes work and how to set them up in relation to one another to get a proper system running. In my understanding the Model Matrix is the matrix ...
2
votes
1answer
161 views

OpenGL Calculate Matrices

Im trying to switch from the glTranslate etc to my own Matrices, but for some reason it does not work. Here are my 2 functions to create the view- and projection matrix: public Matrix4f ...
-2
votes
2answers
197 views

Rendering structure [closed]

my question is "What is the best way to structure rendering code". Is it better to make a class with a render function that iterates through all game objects based on there name or type and have no ...
0
votes
1answer
216 views

Get world-position in Vertex shader

I'm wondering how I can get the final position of a vertex. I use glTranslate in my render code, and I'm not getting the world-coordinates correct. My world is devided in chunks and my position get's ...
0
votes
1answer
283 views

GLSL Shaders-> How to manage?

As your game get's bigger and bigger, you will use more and more different shader effects. Let's take an easy example: I have clouds in my voxel-based world, and I want to give it a blue-ish tint ...
0
votes
1answer
355 views

Drawing the same scene with perspective then orthographic projections

I have a scene that I'm rendering first with a perspective matrix. I then want to rerender it in a different viewport using an orthographic matrix for a top-down 2D view of the scene. I think I may be ...
1
vote
1answer
240 views

OpenGL / Assimp oddity or error?

A friend and I are working on developing a game engine in C++. He doesn't live anywhere near me, so we use Dropbox to sync our files. I opened his project to test his code, and I kept getting errors ...
3
votes
2answers
303 views

Using a programmable pipeline in a game engine

As a learning experience, I'm developing my own 3D game engine using OpenGL. I'm a little confused as to how to implement my rendering engine such that it uses a programmable pipeline while still ...
0
votes
2answers
892 views

Screen or World Coordinates to tile Coordinates

I have Plane made of tiles in opengl. I start drawing them at (0, 0, -20) after that i do my translations so that the view is rotated somewhat similar to an isometric (kind of) perspective. I'd now ...
3
votes
2answers
209 views

Extract smaller frustum from camera frustum?

Background: I was thinking of implementing multiselection by performing a frustum culling on a sub-part of the screen. Problem: Given total screensize, a rectangle on the screen (pos, size), and ...