The Velocity Engine by Reflexive Studios
Icewind Dale 2 Lead Designer, J.E. Sawyer of Black Isle Studios describes
Reflexive Studios' Velocity Engine used in Lionheart as the following:
It uses software anti-aliasing. This smooths the edges of sprites into the
background, removing the pixelated edge that you often notice in Icewind Dale
(look at a screenshot of a dark character standing in the snow for a good
example of this). A lot of the press folk looking at the game thought it (Lionheart)
was running at a much higher resolution than it actually was. (Ed: Because
it looked extremely smooth.)
The graphic data files are .jpgs (JPEG) with an excellent compression:quality
ratio. They take up very little space, which is often a big concern for 2D
games.
The character models and animations are 3D. Animations traditionally take
up a lot of storage space because you have to save off every frame to a separate
2D image and play it back like a flip-book. The character models in Lionheart
are rendered in 3D, then put in the scene as a 2D image, so the main memory
hit is in RAM.
You can run an "editor" version of the EXE which is fully functional,
but also gives you level run-time access to the editor. This is really terrific.
You can move around objects, swap out scripts, and change object properties
while the level is running.
From what I can tell, it's almost entirely script-driven. There are drawbacks
to this, but it makes the engine very flexible.
The engine is 2D, but gets around a lot of the traditional 2D problems.
* The engine has been used in at least three very different games: Zax, Ricochet,
and Star Trek: Away Team. Whether you liked those games or not, they do show
that the developers can easily modify the engine for a number of different roles.