Yes, before Appeal used pretty voxels for Outcast, NovaLogic was running their Voxel Space terrain engine for their various military simulations. We took a look at the Delta Force II demo, read on if you want to know what it's like.

As Old Man Murray would say, "First things first!" Let's talk voxels. Some of us here at Sharky Extreme really love voxels. Just mention the word and for some twisted Pavlovian reason we start drooling. Voxels, much like polygons, are a way of drawing 3D graphics. A single voxel is a point in space with x, y, and z coordinates, color, and a translucency level. In game play, they have the advantage over polygons of allowing vast and "organic" land. The disadvantages of voxels are that they don't use your 3D hardware acceleration and can be really ugly sometimes, especially up close.

Delta Force II uses NovaLogic's Voxel Space 3 engine, which supports 32bit 3D acceleration of non-voxel graphics. The levels consist of very wide-open areas. In several situations we were sniping from six hundred meters away or more. (One impressive part of Delta Force II is its realistic ballistics. Bullets are influenced by wind and gravity and can pierce walls if their caliber is high enough.) If areas with the same detail, including rolling hills and grass, were drawn in a polygon engine, frame rates would choke to death. There would just be too many polygons to draw. The tradeoff is that everything up close looks like Old Man Murray's liver spotted skin, mottled and sickly. But when you consider the concept of Delta Force II, an outdoors squad tactics FPS, the trade-offs are worthwhile. Who cares if they look a bit ugly up close when you can pick them off from the grassy knoll?