OpenGL

Display Lists in OpenGL

This post is a brief tutorial on how to use display lists in OpenGL. An working and self-contained example is given below using LWJGL. Display lists are an essential feature of OpenGL to improve the rendering performance of your application. You can think of them as kind of a macro for OpenGL commands that you name, record and call at some point in your game. More specifically, you assign an integer handle to a sequence of OpenGL commands and call the commands identified by that handle when you need them. (more…)

By admin, ago
Java

OpenGL Picking in 3D

This blog post explains a common and versatile approach to OpenGL picking called "ray picking". An example in pseudo-code is given below. Picking is the process of finding objects in your scene based on user input. Most commonly, you want to determine what object a user has clicked with his mouse. The 2D mouse coordinates serve as a reference on the view port to identify the projected objected that has been clicked. A similar scenario is a first person shooter, where the gun is basically the picking pointer. If you shoot the gun, the trajectory of the bullet is traced through the scene and collisions are detected, similar to a laser pointer shooting a ray through a scene until it hits an object and marks it with a small red dot. (more…)

By admin, ago
OpenGL

LWJGL Example Base

This post contains the LWJGL base class that I use throughout the tutorials and examples. It basically sets up LWJGL and OpenGL which I otherwise would have to do over and over again in the individual examples. In addition, this makes the code in the tutorials and examples more readable by focusing on the important things. (more…)

By admin, ago
Dies Und Das

Fly Me To The Moon

Es ist nun fast zehn Jahre her, dass ich ein Instrument länger als 15 Minuten in der Hand hielt. Damals spielte ich einer Punk-Rock Band und versuchte mich an einer Reihe von Instrumenten, bis man mich aus Qualifikationsgründen zum Sänger umschulte. Dann zog ich aus Göttingen nach Berlin und von Berlin nach China, was unserer Band ein Ende setzte. Als ich aus China zurück kam und wieder nach Berlin zog, hatte ich kurzzeitig nochmal eine Band namens "Die Vier Eukalyptischen Reiter" in der wir in einer Drum-Piano-Bass Kombination einen eigenwilligen Jazz aufzuspielen wussten. (more…)

By admin, ago
Java

JOGL in Eclipse

This getting started-tutorial is intended for JOGL users that are mere beginners. It helps to setup a recent JOGL installation in Eclipse on Windows. There is a video-walk-through further down the post, in case you dont feel like reading. (more…)

By admin, ago
Java

JOGL Download

You are right in this page if you are on the quest for one of the following:

  • recent JOGL binary distribution download
  • precompiled Windows Java OpenGL bindings
  • you just can not find the place where to download JOGL :)
(more…)

By admin, ago
Dies Und Das

crossdomain.xml Demystified

Recently, I noticed an increasing number of requests to a file crossdomain.xml on all our subdomains. A vaguely remembered that this is about Flash trying to access resources on our site, but I didnt really know exactly what it is for until I did some research. (more…)

By admin, ago
Java

Keine Sessions in Tomcat / JSP

Ab einem gewissen Trafficvolumumen beginnt die Sessionstabelle die der Tomcat auf der Platte hält stetig zu wachsen und täglich größere Ausmaße anzunehmen. Da der Tomcat einen großen Teil der serialisierten Sessiontabelle im Speicher hält, kann das zu einem akkuten Crashrisiko werden, wenn der Tomcat bis zum Limit wächst (oder das OS zu swappen beginnt). (more…)

By admin, ago