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Nikolai Wuttke edited this page Nov 1, 2022 · 39 revisions

Welcome to the RigelEngine wiki!

Modding support

Info for developers

Command line options

The most important command line options are:

  • -l: jump to a specific level. E.g. -l L5 to play the 5th level of episode 1.
  • --player-pos X,Y: To be used in combination with -l. Places the player at the given position instead of the regular starting point.
  • -s: skip intro movies, go straight to main menu
  • -h/--help: show all command line options

Debugging features

To enable debugging features, launch the game with command line option -d.

At any time, you can press F6 to toggle showing a FPS counter.

While in game, you can:

  • press D to toggle showing some debug info text
  • press B to toggle showing objects' bounding boxes. objects that harm the player on contact will have their box drawn in red, others in green.
  • press C to toggle showing collision data. This draws yellow lines on top of the map in all the places where tiles are considered solid. It also colors in ladders and climbable pipes.
  • press G to toggle drawing a tile grid on top of the map
  • press S to enter single-step mode. This will stop time from advancing in the game, making everything stop. Pressing space bar advances time by exactly one frame. Pressing S again goes back to normal.
  • Press F10 to toggle god mode (player takes no damage).
  • Press F11 to immediately win the current level

Differences to the original Duke Nukem II executable

RigelEngine aims to match the original gameplay as close as possible, while also improving on the experience in some aspects, and offering optional modern enhancements that wouldn't have been possible on original hardware of the time.

Improvements

  • Sound and music volume can be adjusted
  • Display settings can be changed easily (windowed/fullscreen mode, V-Sync on/off etc.)
  • Up-scaling always preserves the correct aspect ratio
  • No loading screen when starting a new game/loading a saved game
  • No message boxes that delay loading or saving a game
  • Menus are much more responsive
  • Limitations on the maximum number of objects in a level have been removed.
  • In the "save game" menu, pressing ESC (or gamepad button B) while entering text for a saved game goes back to the list of saved game slots, instead of leaving the "save game" menu.
  • Improved gamepad support: Common modern controllers (Xbox, Dualshock, etc.) are supported out of the box without any calibration or configuration needed.
  • A new pause menu allows access to save/load/help/quit menus when using a gamepad (open using start button)
  • Multiple sound effects can play at the same time. The original game only allows up to two effects to play simultaneously, and only if the two effects use different hardware components (AdLib/OPL2 vs. Sound Blaster).
  • Lifted limitations for number of simultaneous explosions/particles/effects on screen.
  • It's possible to skip the bonus screen between levels by pressing Enter/ESC/controller button A or B.

Optional modern enhancements

  • Widescreen mode: Uses the full width of the screen to draw the world during gameplay, instead of black bars on the left/right. This alters gameplay, since some enemies can come into view sooner than intended, and hidden parts of the level can become visible.
  • Quick saving/loading: Makes it possible to jump back in time to an earlier point while playing a level. Press F5 to save, F7 to load. On a gamepad, hold the "select"/"back" button or equivalent and press the shoot button (X) to save, jump button (A) to load. Currently, there is only one save slot, and the saved game will be deleted when quitting the game or finishing the level - the quick save is not stored on disk. This is planned for a future update, though.
  • Smooth scrolling & movement mode (aka 60 FPS mode): Makes the game visually run at a higher framerate by adding intermediate frames for camera and object positions via interpolation. Game logic still runs at 15 FPS in this mode, so the gameplay is unaffected. But visually, the game looks much smoother.

Fixed bugs

This is a list of bugs that occur in the original Duke Nukem II, but are fixed in Rigel Engine.

  • When dying while cloaked (e.g. by touching a force field/reactor) and respawning at a checkpoint, Duke stops being cloaked, but the item remains in his inventory, preventing a new cloak from spawning.
  • When music playback is disabled, the Apogee Logo movie will keep playing forever until a key is pressed, instead of moving on to the intro movie
  • Placing a Blue Guard enemy in the air will cause the game to lock up due to infinite recursion
  • The game can crash on some levels when playing on hard difficulty and opening the help screen while in-game.
  • The boss health bar for the episode 3 boss is not proportional
  • Ammo display is not proportional when using the flame thrower
  • Secret Bonus 4 can't be obtained on levels that contain the collectable N-U-K-E-M letters
  • Various minor animation glitches
  • The horizontal sliding door actor has incorrect collision initially: The rightmost tile is not solid, and shots can pass through. Once the door has opened and closed once, it behaves correctly.
  • When jumping off an elevator while in the air, Duke can sometimes clip through the elevator when reaching the ground.
  • The turkey shows a floating 100 when picked up, even though it doesn't give any score.

Preserved bugs

Not all the bugs in the original game have been fixed, in order to keep the experience as close to the original as possible.

  • Watch bots (the robot with the big eye that jumps around a lot) can sometimes clip through the ceiling when jumping, damaging Duke even though he should be safe.
  • The collectable letters (N, U, K, E, M) each give 10.100 points instead of just 100. Contrary to what the game says, there is no additional 10.000 point bonus when collecting the letters out of order.
  • Bonus 6 (all red boxes with fire bombs opened) is always given in case a level doesn't contain any fire bombs. This is not the case for other bonuses (aside from 7).
  • Similarly, bonus 7 is awarded if a level does not contain any bonus globes.