Portal - Level Designer
Kim Swift
GameSpot:
We understand that Portal's roots date back to a computer science project created by a group of students. How did it become what it is and make its way into The Orange Box?
Kim Swift:
Two years ago, everyone on the Portal team (with the exception of our writer Erik Wolpaw) were students at DigiPen Institute of Technology. One of the course requirements is that each year you have to create a game from scratch for our game class. For our senior-year project, we made a game called Narbacular Drop, which is the predecessor of Portal.Every year, DigiPen holds a job fair for graduating students where they gather all sorts of developers from across the country to come in and take a look at the seniors' projects and resumes. A couple people from Valve swung by and took a look at Narbacular Drop and invited us in to demo the game for Gabe Newell. After 15 minutes or so, Gabe stops us and asks, "What are you guys doing after you graduate?" and offers the entire team a job on the spot to make a game based on Narbacular Drop using the Source engine.
After suffering from massive heart attacks, we all jumped at the opportunity and started working on Portal. Two years later and we have the utmost honor to be packaged in The Orange Box with two of the best games of the year.
GS:
The game gradually ramps up in difficulty as players become more familiar with the gameplay. Tell us about how you managed the progression of difficulty without making the game frustrating.
KS:
Play testing, play testing, play testing. Every week during development, we would bring in someone new to play the game from start to finish. We wouldn't just have them fill out a questionnaire at the end of the game, but we'd watch them play through. There is so much value watching someone play the game. It's incredibly obvious when someone is stuck, or is having fun. We let our play tests dictate how to teach our players and when to ramp up the difficulty.
GS:
The game has a very satirical sense of humor. Where did that come from?
KS:
We all seem to have a pretty quirky sense of humor on the Portal team, and part of that humor has seemed to leak into the core of the game. The other part is our awesome writer, Erik Wolpaw, who wrote the monologues for the game's ever-present disembodied voice, GLaDOS.When we first started working on the game, we didn't really have a story or any other characters besides the player. Our feedback was that the game was pretty lonely, so we talked to Erik and he agreed to help us fill in the gaps. It was really great to see that our players found the dialogue to be rewarding, and many people would completely stop what they were doing to laugh at GLaDOS's comments.
GS:
Tell us about how you approached Portal's design. What was the most difficult part? The most fun?
KS:
Designing Portal was a very collaborative and iterative process. For instance, to create a map, the entire team would get together in a conference room with a whiteboard and sketch out which gameplay ideas we'd want to use. One of us would quickly get the map up and running in a few days, and then we'd get someone who had never seen it before to play through. Based on our observations from the play test, we'd readdress the map, make any alterations that everyone agrees on, and run another play tester through. Rinse and repeat!One of the most fun things about designing Portal was watching people play through a level in a completely new way that we hadn't thought of. Seeing this in many cases gave us the inspiration for a new puzzle or mechanic.
Portal - Programmer
Jeep Barnett
GameSpot:
Where did the idea for Portal, or its original version, Narbacular Drop, come from?
Jeep Barnett:
Our team at DigiPen was required to create a game as a class project each year. We spent several months brainstorming ideas for our senior game, and the seamless portal graphical effect was an element in a few of those concepts. Narbacular Drop was a combination of those ideas stripped to the core portal mechanics. It ended up being a proof of concept for the portal gameplay ideas we developed in Portal.
GS:
What were the unique challenges of programming the game?
JB:
Any new element added to the game was expected to interact with portals and that often meant plumbing a much larger system of the Source engine. Everything from rendering, to audio, to AI was modified to accommodate portals.The biggest undertaking was modifying the physics engine. We had to allow the player to dynamically cut holes in the static environment and process those collision changes in real time. Objects on opposite sides of a portal needed to realistically collide with each other. This code was rewritten several times for improved precision and performance.
Then there's the really weird stuff. In a standard Euclidian space you can ignore problems such as, "What if an object collides with itself?" In Portal, the shortest distance between two points isn't always a straight line. If the player's feet pass through a floor portal and touch a wall on the other side, they need to be able to stand on that wall as if it were a floor. For those challenges we first form an expectation for how a portal would behave in the real world, and then we assimilated that behavior into the game.
GS:
In Portal, it's possible to enter a room while leaving it. How were you able to wrap your mind around your own game?
JB:
I find it pretty amazing how well the human brain can adapt to reason within new rule sets. For example, a chess player sees beyond pieces on a grid to perceive the paths that each piece can travel. Likewise, anyone should be able to naturally navigate a room using portals after a little hands-on experience with Portal.Before we had Portal or even Narbacular Drop for that hands-on exposure, we created a simple 2D portal demo. Playing with that allowed us to come to terms with the more advanced portal concepts, such as how momentum carries through portals.
So you've met the people behind Half-Life 2's incredible gameplay and engrossing story, the ones who made Team Fortress 2 look so cool and feel so different, and a couple of the minds behind Portal's weird science and unique wit. As you can see, Half-Life 2: Orange Box doesn't just represent a stunning collection of unusual games, it also represents an interesting assortment of professional gamers, people just like you. Thanks for reading, and by the way, if something is iterative, it involves repetition. To use that in a sentence, here's hoping Valve's success with The Orange Box is as iterative as its production.
Have thoughts on The Orange Box or the people behind it? Want to hear from more developers? Let us know!
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highroller124 posted Oct 19, 2007 2:10 am PT (does not meet display criteria. login to show)