"I Never Should Have Written All of Those Tank Programs" -- Kevin Flynn

Considering how little experience I had with Duke Nukem 3D's scripting language only a couple of months ago, I'm rather amazed that one of the first features I implemented into TRON: Anti-Virus was also one of the features that I thought would be the hardest to implement; a drivable vehicle. Vehicle mods have been done for Duke3D/eDuke32 before and after only a few minutes of looking at the code, I had an idea of how to go about it.

Getting the movement controls to work and the appearance of manning a swiveling turret that rotates independent of the vehicle was finished in no time. What took much longer was completing HUD. Every instrument on the HUD actually works, and they're all graphical representations, which includes a compass, an overhead view of the tank showing the angle of the turret relative to the chassis, ammo, vertical angle, speed, and armor.

Finally there was the projectile, which I foolishly decided I wanted to have working before I took a break. The tank is one of the three most recognizable and iconic items in the original film, so I really wanted the weapon to look like it should. This required a lot more effort than typical Duke animations would - 5 different components total; the impact flash, '2 different particles', the blast 'ring', and the pathing 'trail' following behind the projectile as it moves through the air. The biggest problem here was the blast ring, because in order for it to mimic the film's effects, it would have to align itself to whatever surface the projectile hit. In later games this is a rather common effect - the first time I remember seeing it was with the shock rifle in Unreal. But none of the default Duke weapons do this, which meant a hairy bit of extra code for what is otherwise just a basic explosion.