Perfect Dark - Game Engine

Game Engine

The Perfect Dark engine is a modified version of that of GoldenEye 007, and many of the gameplay features are unchanged. For instance, the manual aiming system, originally inspired by Sega's Virtua Cop, is graphically enhanced but essentially the same. Players can crouch, duck and lean but notably there is still no ability to jump. Despite this, it is possible to drop from most ledges, a feature rarely used in GoldenEye 007. Most weapons have a finite magazine and must be reloaded after a certain number of shots. Interaction with the environment is via a single "Use" command, which opens doors, activates computers and so on. Enemies and players can disarm each other at close range, and the player can use this feature to steal weapons or knock foes unconscious. Like GoldenEye, Perfect Dark uses location-based damage; for example, a shot to the torso causes more damage than a shot to a limb. However, unlike GoldenEye, in the single-player mode a head shot on a guard is instantly fatal on any difficulty level.

The engine also includes a number of graphical enhancements, the most conspicuous of which is the option to play in hi-res 640x480 graphics. The Nintendo 64 Expansion Pak is needed to access the game's campaign and most of the multiplayer features, although a limited subset of the Combat Simulator options are available without the device (around 35% of the game is playable without an Expansion Pak, as estimated on the game's box and Instruction Booklet). The lighting system was improved so that gunfire and explosions illuminate areas dynamically, and lights can be shot out to create darkened areas. Further progressions from GoldenEye include weapon-specific reloading animations, and more elaborate gore effects which allow gunshots to project enemies' blood onto nearby walls and objects. Another graphical novelty is the "dizziness" effect; if a player is punched, poisoned by a throwing knife or shot with the Tranquilizer gun, their nausea is represented through a motion blurred view. The degree of blurring increases with dizziness, and a badly stunned player may have difficulty seeing anything at all. The disadvantage of such detailed graphics is that the frame rate inevitably suffers in some areas; this was one of the main criticisms levelled at the game by reviewers (see Reception section). The same limitation was present in GoldenEye, but the other graphical enhancements in Perfect Dark serve to exacerbate the problem. In multiplayer, the game must render the scene separately for each player, although at reduced resolution. Nevertheless the frame rate issues arise again, particularly if a large number of Simulants are involved.

Perfect Dark's engine offered audio features that had not been available on the N64 before; for example, it was one of the few games to offer Dolby Surround Sound. Some of the game's audio data was compressed into MP3 format in order to fit into the relatively small storage space afforded by a cartridge, though the music was sequenced. There is full voice-acting for all the dialogue, and the guards can be heard having conversations amongst themselves about the events of the level. Additionally, both NTSC and PAL N64 systems run the game in full screen, without the "letterboxing" seen in many PAL releases, and there is a 16:9 option for use on widescreen televisions.

The artificial intelligence of the guards includes the ability to call for help and sound nearby alarms. The guards can be alerted by nearby gunfire, and the various weapons in the game have distinct volumes; for example, guards are less likely to be alerted by suppressed pistols than powerful rifles. Enemies can also throw grenades and, if the player disarms them, draw a secondary weapon. One criticism raised of GoldenEye 007's guards was their weakness at very close range, since their weapons appear to shoot straight through the player. This is resolved in Perfect Dark, whose guards can deliver punches and kicks at close range, inflicting damage and causing dizziness. In GoldenEye, the guards could not see through glass — a feature included deliberately so that the player could spy on foes through windows. This aspect is retained in Perfect Dark, although enemies can now see and shoot over railings. In the later stages of the game, the player encounters Skedar enemies still in reptilian form, and while the Skedar weapons and characteristics are different, their AI is qualitatively the same. The multiplayer Simulants are considerably more advanced, and can exhibit abilities similar to those of a human player but with some limitations. For example, they have the ability to complete multiplayer objectives, such as capturing the briefcase, but they are not able to use some of the weapons, such as remote mines. Simulants make no attempt to avoid simple traps such as proximity mines or sentry guns, even on the highest skill setting.

There are a number of bugs and technical issues in the game engine. For example, in the first level, a flaw in the level geometry makes it possible to pass through a supposedly solid wall, allowing the level to be completed on the easiest difficulty in just a few seconds. Also, as with many older FPSs, players can use a technique called straferunning (or "speed-strafing") to exploit a bug in the engine whereby moving diagonally allows the player to move faster than by running forwards or sideways alone. This technique is almost essential to achieving some of the target times required to unlock cheats.