I’ve been looking into graphics engines recently, though this can only be a part time hobby for me since I should be doing my PhD work. I’ve mostly been looking at two in particular:

• Ogre
• Irrlicht

Both of these seem to have some pros and cons, which I will be detailing in a second. I cannot decide which one I prefer though so maybe you can help me out? Comments are welcome.

Ogre

Lets start with this one. Perhaps the more fully featured engine, and used in some pretty famous games, it comes out of the box with some nice shader support and a great tutorial which is easy to follow and gets you creating a scene in no time at all. This is one of my main problems though: the tutorial really hides all the workings of what actually goes on in the engine from the tutorial follower as its all contained in a TutorialApplication class which handles things like setting up a camera, and rendering the settings box and gui. This is very nice to get a quick application going but doesnt really teach you anything about the API. I suppose this might be explained further in the tutorial but I never followed it that far (probably shouldnt admit that but never mind!).

Irrlicht

Had never heard of this one before I did some googling. It is less well known as far as I can tell, but still used in some highly commended games. The nicest difference is the tutorial exposes all the code to the user, which can make the initial tutorials a little lacking in functionality (eg. no fps mouse controls) but helps you understand much more.

Comparison

Some differences in the use of the two engines are:

• Transformations - Ogre uses quaternions, a rotation around a vector, whereas Irrlicht uses rotation matrices which are much easier to comprehend
• Utility classes - Irrlicht has such things as vector3class T which call a templated function for class T. Ogre uses a built in (though it may be a typedef) Vector class.

I am planning on adding to this post as I find more differences and this is only a brief first impressions post, and I still cannot decide which I prefer!