Here is the interview:
TS-SWL: With the ending of Episode 2 going directly to help the feeling of “must play Episode 3 now” could you give the current estimated date for Episode 3’s release?
DL: We haven’t announced a date for Ep Three just yet.
TS-SWL: Are there any current plans after Episode 3 to have a Half Life 3?
DL: We haven’t announced anything specific, but Half-Life won’t end at Episode Three – hang on to your crowbars!
TS-SWL: For Portal, can you explain in layman’s terms how the engine allows the mechanics to make it so you can go from one point to another? Does it duplicate the room after a portal location is selected or is it something else?
DL: A portal is two planar rectangles in 3D space. When both portals are placed we build a mathematical formula that converts position and angle values from one portal to the other. Rendering the portal is done in a separate pass where we use that formula to covert the player’s view position and angles to the view they see through the portal.
We also generate special collision data to represent the portal hole by grabbing collision data near each portal, combining them, and carving a rectangular whole through the center. When the player is near the portal they use this collision data instead of the standard data, allowing them to pass through the wall. We then use the conversion formula to teleport the player to the proper position after they’ve gone more than halfway through the portal.
It’s of course a lot more complex than that, but that’s the basic idea.
RIP Max-Tuesday, November 2 2007
You will be dearly missed.
