EXOCEL: GENESIS

Claude Levastre (Lead programmer)

The Exocels are really disgusting creatures. How did you come up with this idea? Our first idea was to create a small creature that would differentiate itself from the others humanoid creatures we had in the game. Then the idea of creating a parasite came up rather quickly. Our first, early design was a simple 2 tentacle creature we called the slug. The slug was not really credible in terms of design, but it already had the abilities to throw and stretch a tentacle and to move on ceilings.

The Exocels: a never-seen-before animation process.

We wanted to avoid the bug-like look, and we soon preferred a quadruped that moved like an octopus. With this new design we understood that it would be really tricky to create animations with a traditional process. Each tentacle is made of 6 joints. Counting 5 tentacles this meant creating the same amount of animation for this little creature than for a human. Provided that the monster also had to have the ability to move on ceilings, it was really impossible to imagine all the situations that could occur. Moreover, as the Exocels movements are quite slow, each mistake in animation would have been visible to the player.

The quadruped version: the final design of the Exocel.

So we started an AI which animation was managed through programming, reproducing the movements of an octopus. To render the tentacles we used the « Verlet » physics: the tentacles are animated like strings with weight and rigidity parameters in association with a quadruped walk model. To program the walk, the principle is quite simple: two tentacles have to be fixed so that the body can move. Each tentacle also searches for a fixation point. So a tentacle cycle basically reads like this: « can I unhook myself, if yes I look for the next fixation point and I stay there until the body has joined me.

An autonomous and challenging creature.

To kill its prey the Exocel has a stinger that is handled the same way as a tentacle. The stinger has a range of 3 meters, which allows the Exocel to hit even from high ceilings.

The Exocels have the ability to avoid each others, and if they are blocked on a ceiling they can let themselves fall to the ground to continue their way. This Ai makes the Exocel an autonomous entity that has the ability to move in an environment without additional scripting. We could put ten of them in a room, but it would be too difficult. With 3 to 4, you already have to be really organized.

As a result, the unstoppable movement of the Exocels, their number, their capacity to cast themselves on ceilings and to strike from a 3-meter distance makes it a stressful creature for the player.

Adding the fact that you also have to prevent them from reaching dead bodies, each fight in the game involving Exocels becomes unpredictable and terribly intense for the player. My advice: maybe use the flamethrower?

DIRECTING THE FEAR

Benoît Martinez (Computer Artist) & Lionel Barthélemy (Level Builder.)

BM: One of the difficulties when you try to create fear effects in a horror game is the fact that the universe and action must be set so that the ambiance is set the whole walkthrough long. It is only when this part is completed that we can start building surprise effects. Everything falls into place during the 3 last months of the development process.

Fear mechanisms

The first point is that in order to make the surprise effects work, it is important that their directing does not cut the action. The player must have the ability to act during a surprise effect, maybe suddenly pull his stick and see the hero jolt with him. In a horror game, the mechanisms are like the ones found in a movie: first we try to create an oppressive atmosphere with flickering lights, and suspicious sounds. The surprise effects are then located according to the walkthrough: we won’t set them after a big fight but rather before, and usually when then player does not expect it.

We work a lot on the sounds with a focus on FX and heart beats that embody a physical pressure on the player. We play with the poundings to make the tension rise, which can happen just before or after a fight.

Testing the fear.

LB: The difficulty for us is that those fear effects does not work with us anymore. We have to test it on other level builders. But as we all work in the same room they all know which scene everyone is working on. So surprising them is always a good sign.

We had that scene on the oil rig where a mercenary would fall from a tower and fall at the player’s feet. The shout and the impact made everyone laugh so we removed it right away. The difficult thing with horror is that when you do not reach your objective, you end up with the opposite emotion.

But in Cold Fear, thanks to the stressful action and oppressive atmosphere, our surprise effects should work quite well. The players will jolt like lightbulbs.

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