Monday, April 13, 2009

Observations for each of the 5 guidelines

1. "make the AI visible to the player"

In BioShock, the AI has a hard time seeing the player and appears to have to "think" about whether it should attack or not. This is how it appears, the real reason is the line of sight issue. This is a problem with the overall tuning of the visual cue system that was implemented by the designers. It would take into consideration the light, path of sight, sound, and some other neat features to determine where the player is. This is the reason that it "appeared" to see you, but did not act on it. It had to determine if the factors were great enough to approach.

More information can be found here:

2. "only implement AI that the player can detect"

I have two points to this statement that I feel are critical.

Programming- is a big part of AI optimization and Lua seems to be the language of choice. Lua is an extremely well versed program and if understood and used correctly, AI optimization is a fairly simple task.

Design- is the other part of successful AI integration and optimization. When designing for AI Cooperative Integration, be careful to fully understand the benefits and disadvantages that come along with it. Fallout 3 did an okay job at bringing the CO-OP AI into the story, except for the fact that they get stuck in strange places and are extremely finicky when it comes to Karma and deciding to join or abandon you. (I think the threshold should have been set higher.)

3. "avoid behaviors that appear mechanical"

The simple answer is do not make your AI act or look like a robot. Make it look, feel, and act like a human that you can easily interact and communicate with.

More information can be found on Facial Expression Recognition here:

An interesting theory that I would like to pursue is a modified version of the Uncanny Valley theory. This would be beneficial in the design and development of AI. To avoid the appearance of mechanical structuring, one could use the simple concept of facial expression recognition. If the AI or player appears "mad," then increase attack rate. If player appears "happy," increase sneak or call in some other action related to attack - while also taking into account other body movements, actions, etc.

: If I am being attacked by the AI and start kicking its ass, then they are going to need help. The face of my character should reflect an intense, focused look, not the look like I'm skipping down a tree covered path. This face would be appropriate for when I find cover or am camping.

More information can be found on Facial Expression Recognition here:
4. "show the player AI that makes choices"

Killzone 2 does a good job at this. If any type of explosion is thrown at you and you are not on the ball, your AI counterparts will try to assist you in getting the explosive back at the enemies or at least out of the area. This is also true for the opposing AI. They do the same thing when an explosive is thrown at them. This is a fairly easy concept and fairly old one at this point. The first time I noticed this was COD:3. This is also easy to implement with code and correct path placement. Something I think that we will see more of in the future is a direct CO-OP AI becoming more useful. This is seen in Resident Evil 5 regarding how you get help going up ladders and over the walls. Army of Two tried, but did not really succeed. Still they gave it a great go. There are always other ways around in real life, as it should be in the video game world. But the most direct way is almost always going to be to get help from a friend. The AI has to be in the correct place and make the correct choice.

5. "give the player reason to see more than is really there"

The trouble with Fallout 3 combat is that it changes from turned base to free fire (perfect intensions) but the communication about combat with the AI did not. This really hurt the game, I think the intentions and the overall AI were great but the execution in regards to the AI was just lacking that "something special." The reason I wanted to play this was for the AI and the "puzzles" that you had to overcome . I wanted to see if there really was more. There is part of the game that if you try to shoot at or kill one of the guards, the game would not allow this. It would knock him out, but you could never actually kill him. The only way to escape the situation was to flee. This is an overall flaw in the game design. If you are going to make a truly sandbox style of game, which Fallout 3 is, and do not want to limit the player in anyway (the ultimate goal of a video game, right?), then this should be your rule of thumb. "If your player can die, by good or bad hands, then your entire world and everything in it should also be able to die, good or bad."

Tuesday, February 3, 2009

Resident Evil - Degeneration (Hero's Journey)

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1. Ordinary World

The ordinary world that I see in the beginning of the movie is in the airport were Clair Redfield (main character) introduces herself to Ronny (child), this is a world (setting) that does not contain the evil zombie bad guy, YET.

2. The Call to Adventure

The call to adventure starts when Clair realizes that the airport is becoming over infested with zombies. She was asked by Ronny's Aunt to watch Ronny while she went to get the limo, so it is now her responsibility to care and protect.

3. Refusal of the Call

What I think was her refusal was either when she did not really want to help Sen. Ron Davis but in a way felt obligated because without her help the poor sap would have been killed almost instantaneously. She really didn't want to do it, and that is what makes this the refusal.

4. Meeting with the Mentor

When Clair is in the VIP room and hears something outside the room and goes to check the noise. It turns out to be Kennedy and his group, Clair is trapped and ducks to avoid getting bit, Kennedy fires and take the zombie out. She is kneeling down and looks up to see Leon Kennedy there and says.. "Leon, what are you doing...." let's get out of here responds Leon, implying that they have not only been around each other before but that it looks like Leon is who taught Clair what she knows about the zombies and guns.

5. Crossing the First Threshold

The first threshold that Clair crossed was when Leon Kennedy was in the process of getting the group out of VIP room. They are surrounded by zombies and Leon just can't make it to save her. Clair so far had been very timid and laid back until she needed to get in there and save Ronny's life. Leon throws her the gun from across the room, Clair catches it and starts kicking ass. 4 or 5 zombies go down, she grabs the girl and they high tail out of there. This could also be Enemies, and I may add it there also but I felt this is an important stepping stone for Clair.

6. Tests, Allies, Enemies

This being resident evil there were tones of fight scenes where it was human vs. zombie. The bigger scenes had help from supporting characters. The main character Clair was not the toughest of all of the allies so for the big acts it involved Leon and Angela doing most of the fighting. Resident Evil is good about that, they spread out the character development across three sometimes four different characters.

7. Approach to the Inmost Cave

The approach to the inmost cave would have to be when Leon and Angela are in the middle of a virus transformation at the WilPharma facility. This is also part of the ordeal; please see below at the ordeal line.

8. Ordeal

Angela’s brother has a strand of the G-Virus and transforms into a huge, big scary monster… (see above). Angel has to cross a bridge and realize that it is no longer her brother and she must shoot to kill him to save her own life. Leon comes to help rescue her because it takes her awhile to realize that he will kill her if she doesn’t kill him first.

9. The Road Back

The road back started about 3/4 of the way into the movie. They first were trapped in the airport, then sent to the facility and then made there way home. This is shown in the very end when Leon asked if she need a ride and she says “I have a limo waiting on me”, if you recall back to the very beginning, the aunt says she is going to get the limo pulled up.

10. Resurrection

Zombies are zombies… there were like 100 resurrections in this movie. The final fight scene between Angela w/ Leon and her brother, I counted the times he came back, he resurrected six, count ‘em SIX times. Every time he died there was more and more blood and guts, but he was a persistent monster.

There is also a brief moment in the end that they are cleaning up the facility and one of the workers finds part of the brothers hand / claw, this means that there is now another trace of the G-Virus.

11. Return with the Elixir

There was no elixir they found or returned with. Instead they captured the guy with the virus and brought him to justice. One other small part may have been when they captured all of it on video. This was the way of showing the world what existed and what had been done by the WilPharma company.

Monday, January 19, 2009

Fallout 3 - A.I. Study (PS3)

The game I will be looking at is Fallout 3 for the PS3.

So, Fallout 3 is a very complex game that has MANY elements of A.I., that would be very hard to cover in one paper. I will do my best to pick out the key elements and larger aspects of Fallout 3's A.I.

The first thing you need to know about F3 is that it is fully customizable in just about every way. You start as a new born baby, this is where you pick your gender and body / face type (your father after you pick this, looks like you). As a child just learning to walk you get to pick what attributes you would like to have as your strong suite, you can later build upon other ones but you get three core ones. This is a very brief introduction of the intro and the massive customizing you can do.

… i will jump right in to some of the elements of the A.I.

One of the key elements introduced by Bethesda is something called the Radiant AI system. A very good way to put it is:

Where other games’ NPCs require individual scripting, we can simply provide our NPC’s with goals and our system allows them to think on their own and complete the task.

One of the reasons I know about this is because I have loved all of the Oblivion titles and have been playing Fallout from the start (1 and 2). This Radiant AI system is something that Bethesda has developed in order to have the NPC's become more interactive (no, it does not work every time but for the most part this is a great system).

an example of The Radiant AI sytem glitching... just a little bit... :-)


There is really no limit that can be placed on this system. I tested this system out by waiting, and waiting, and then waiting a little more until I found what I thought was a drunk NPC stubbing out of a bar in MegaTon. So, I don't think he was so much drunk as he was paranoid that someone was following so he would turn around and stubble on something while looking for me (hiding in the dark). As the light came up, we became less paranoid and more interactive with other NPC's, he would stop and pat kids on the head, talk to other NPC's and he even went in and made a transaction with one of the shop keeps before retiring to his shack on the out skirts of town. I tried to follow him into his house but he had locked the door... I decided I needed to take this one step further. I picked the lock on his door and quitly made my way around his house. He had a couple scraps of food, a book and a pistol. I tried to pick pocket him while he was asleep to see what he had as personal effects. This woke him up and startled him both you could see on his face. He looked over to see if the pistol was still in the correct place. I was NOT, this is when he began to panic and got up to head for the door. I shot him in the back, (I know, so mean) he went down with one blast to the head. This is only ONE NPC in the game and not a very important one at that.

Another aspect that is improved upon with F3's Radiant AI system is this; instead of having what is called a pathnod, this tells an AI NPC to walk / run / flee to a particular POINT. F3 made advancements to Radiant AI and created something called a navmesh, allowing the charter to “look” more intelligent by running to a particular AREA, instead of a particular point. They will run behind rocks, buildings, cars, other people, they will do “almost” anything to protect themselves, including running away if you are about to kick the crap out of them. This is an important quality that A.I. No a days have to have or it is considered trash!