Recently I had the great honor to talk to Chris Rhinehart of Human Head Studios about the highly anticipated game PREY.

Questions from Gareth Von Kallenbach
Skewed and Reviewed
http://www.sknr.net

As a fan of 3D shooters, I remember the articles almost 8 years ago that first introduced gamers to the title, and now we are proud to give you an in-depth look at the Hot Shooter of 2006.

I want to thank Chris as well as Jay Boor at 2K Games for taking time from their hectic schedules to make this interview happen.

1. How did you arrive at the decision to resurrect the game after it had been shelved for almost a decade?

Well, actually, the game hadn't been shelved for a decade.  It was originally started around 1995, went through various revisions and was finally shelved in 1999.  Human Head started working on Prey in mid-2001.  We basically started with a clean slate though - a few key design elements carried over from the original but everything else is new.

The decision to resurrect the game came from a desire for a working relationship between Human Head and 3D Realms.  Human Head had completed Rune on the PC and just finishing Rune PS2, so we were setting up our next project.  3D Realms liked Rune and wanted to set up a working relationship with us similar to their relationship with Remedy while working on Max Payne.

2.  Can you tell the readers what enhancements have been made to the gaming engine and what new features it will offer?

We've made a significant number of enhancements across the entire engine primarily for rendering and for the new gameplay in Prey. The rendering has been enhanced by adding in better pixel shader support.  We now have specialized shaders for cloth, hair, skin, parallax mapping, screen blurring, and ambient glows. Of course, since portals are a key gameplay component of Prey, code had to be written to support proper rendering of arbitrary portals in the engine.

Enhancements to the game code include:

• Changes to the physics and player code to support wall walking, arbitrary gravity, a vehicle system, and portals

• Networking speed improvements including client-side entities and support for all the single-player game features (gravity, portals, wall walking, spiritwalking, etc).

• Support for DeathWalking - since the player cannot permanently die, code changes were required for the specialized DeathWalk gameplay.

• Code changes to support the AI requirements for the game.

• A large list of misc. things done to support other gameplay elements throughout the levels.

3. What is the background and setting of the game and has it changed any since the original project?

The setting and background have both been altered heavily, but the spirit of the original remains:  Native American mythology against a high-tech alien race. When we took on the project, 3D Realms had a few core elements that they required remain:

• The protagonist is a Native American who is in a dead end job and doesn't care about his heritage

• Aliens abduct the hero and his family

• The hero must go on a type of "vision quest" to commune with the spirit of his dead Grandfather

• Portals - since these were such a key elements in the original Prey design, they had to carry over into this incarnation of Prey

4. What weapons, vehicles, and enemies will players encounter, and what are some of their abilities?

Weapons:  The weapons in Prey are almost predominately alien in nature so many of the visual designs for the weapons are very organic – some of the weapons are even living creatures or parts of creatures. However, we had concerns that freaky alien weapons combined with freaky alien usage would result in weird and confusing weapons.  So we tried to design the functionality of each weapon into something that people would be familiar with and hopefully get comfortable with fairly quickly. One weapon that stands out as very different from the organic alien weapons is the Spirit Bow.  This weapon is only available to Tommy when he Spirit Walks out of his physical body.  Because of this, the player has the ability to leave their body and scout ahead with the SpiritBow and try to get the jump on enemies.  In addition, certain creatures are only vulnerable to Spirit attacks, so the player has to leave their body to fight this particular creature.

Vehicles:  We have one primary vehicle in Prey: the Shuttle.  This flying vehicle allows the player to traverse large spaces very quickly, so we can build in some very large spaces into Prey - and even let the player fly outside of the ship a few times. The Shuttle has two modes of attack:  Normal attack is a rapid blasting projectile that deals a large amount of damage - very useful for taking out ground enemies and dogfighting.  The secondary attack shoots out a short-range tractor beam that is useful for picking up enemies and throwing them, or for moving things around on the ship. Several puzzles require the use of the tractor beam for moving things out of the way, or positioning certain objects.

Enemies:  There are a lot of varied enemies in Prey, ranging from ground-based creatures, to flying creatures, and even to some creatures that can only be killed when the player is Spirit Walking. We also tried to strike a balance between the types of attacks these creatures perform, as some creatures will be very tactical and run from cover to cover while looking for an opportunity to attack.  Other creatures are melee based and will try to get close to the player to kill them with claws and teeth. Enemies are aware of objects in the game - they know to run to cover points, they know how the health system works (indeed they can run and get health before the player has the chance).  The enemies know if the player is standing near something destructible and they will try to destroy it.  Enemies also know if the player is on wall walk, and can turn the wall walk off causing the player to fall.

5.   What type of multiplay will the game offer?

Multiplay (or MultiPrey as we call it) brings all of the single-player gameplay into multiplayer.  So, we have levels designed around Wall walking surfaces, crazy changing gravity, portals, and Shuttle combat. Players also still have the ability to Spirit Walk and hide their bodies while they try to quickly find and kill opponents with their Spirit Bow. Of course, the body is vulnerable when left behind - so an opponent could stumble upon the body and kill it with a single shot. Prey multiplayer really is something that has to be experienced - all of the gravity changing, wall walking, and portals are disorienting for the first few minutes.  Test players seem to pick it up rapidly and very soon are understanding how the levels are laid out and how best to use gravity and portals to their advantage.

6. Blending action with a detailed plot can always be tricky, how have you attempted to create this element, and will scripted events be a part of the game?

Another 3D Realms requirement for Prey:  The story should unfold around the player, and control must not be taken away during cinematics. We have been doing exactly this - the story unfolds around the player in the form of scripted sequences and dialog with other characters. Control is not locked during these scripted sequences - the player is free to explore the area during dialog. If the player wanders too far away during a conversation, the other character will not unrealistically continue to talk.  Instead, the other character will yell for the player to come back - at which point the conversation continues.

7. The scope of the game sounds amazing, what are some of the biggest obstacles you see in creating the game, and what are your biggest goals for the game?

There have been a number of obstacles we've had to overcome during development.  When we first started, we had a high-level concept but no specific gameplay.  After prototyping and experimenting, we came up with the core gameplay in Prey:  gravity flipping, wall walking, sprit walking, and portals. Also, we were unfamiliar with the Doom 3 tech when we started the project - that was a much larger learning curve than we anticipated.

Techniques for art creation we used in previous games no longer applied, so we essentially had to learn all new methods.  That ate up a considerable amount of time, as a lot of work was thrown out and started over.

Another obstacle we had to overcome, was certain gameplay systems taking a long time to come online.  For example, we spent a lot of time experimenting with different AI techniques that seemed very promising, but in the end, we threw out those ideas to go with a more straightforward programming approach for the AI.  The end result turned out great, but there was a long period of time where we had no AI in the game - which made it difficult for the level designers to design combat scenarios without knowing exactly how the creatures would behave.

It's been a huge learning experience - everything we've learned in Prey we will be applying to future projects.

8.  The use of portals and the wall walking abilities sound like they will add an entirely new realm to 3D shooters. How difficult was it to add them and yet not encounter issues with clipping and camera angles?

We have code in place to keep the portal transitions extremely smooth, to the point where it is indistinguishable that you have just gone through a portal.  This gives us the ability to really set up some "mind-screw" puzzles.  For example, one puzzle has you in a portal maze where you literally can see yourself in it and follow yourself through the maze. Wall-walking had similar code issues - the first task was to get it working solidly.   Once that was in place, we worked on smoothing the camera while on wall walking so it doesn't jerk while walking up onto the walls and ceiling.  You're already walking around on the ceiling the last thing players need is anything to cause even more confusion!

9.  Final Question, can you tell the reader more about the spirit powers and how they will be used in the game?

There is one primary spirit power ability in the game, and two additional powers:  Spirit Walking, Death Walking and Talon. When the player Spirit Walks, they leave their body behind for a short period of time.  The spirit player can then access areas that the physical body cannot:  through force fields, laser beams, through fire, and so forth.  This allows the player to solve puzzles, or scout ahead for enemies. Of course, the player's body is still vulnerable, so care must be taken when leaving the body behind.  If the body is attacked, the spirit player will be instantly snapped back, assuming that the body isn't killed by the attack. Death Walk is somewhat related to Spirit Walk:  When the player dies in

Prey, the game isn't over.  Tommy is pulled into the Land of the Dead, where he must battle for the right to return to the physical world. Depending upon how well the player battles in Death Walk determines How much health and spirit power they have when they resurrect. The player resurrects where they died, so the player can continue right where they left off.  Essentially, this eliminates the need for quick saves.  Of course, we still support quick saves, since there's no real reason to completely eliminate them in case certain players prefer to quick save throughout the game.

GVK: Thank you so much,

CR:  Not a problem.  It was my pleasure