Level Design 101: Implementing the Crossbow

  Hey everyone, it has been a while since I last had an update to my blog so in this post I am going to talk about something I have been working on for In Ruins. A few months ago we decided to incorporate a crossbow into the game. As the game designer it was my job to pick a crossbow and design the mechanics and gameplay around it.

   I looked at a bunch of different crossbows but I couldn't find one that made sense in this world. I needed something that was strong, versatile and had a distinct silhouette. I finally came across this amazing crossbow known as the TAC-15. This would become the base of the crossbow we plan on incorporating into our game.

   The purpose of the crossbow is to give the player a weapon that would allow them to take out opponents stealthily and effectively. We already have incorporated stealth mechanics in the game such as strangling opponents and crouch walking. It only made sense for us to incorporate a weapon that would help players be stealthy.

Modeling the placeholder

Perspective view of the crossbow inside of 3Ds Max.

   I began to model a placeholder model inside of 3Ds Max that would be imported into UDK for testing purposes.

 The model is based of the design of the TAC-15 crossbow. I made sure to keep this placeholder asset simple and relatively low poly. It needs to have a silhouette that sticks out from the other weapons in game.

  After the model is done I went ahead and gave it a simple rig to allow the characters in game to hold and use it.

Wireframe view of the rigged crossbow.

  Since the projectile is an arrow the rig does not need a bone in the muzzle. Typically when I rig a placeholder mesh I add three bones. I add one in the base of the grip, one under the barrel and the last one at the muzzle of the gun. This place older only needed two bones as this weapon doesn't have a traditional muzzle.

Importing into UDK

  Once the model is done and it is rigged and unwrapped I imported the FBX into UDK.At this point the coding for the weapon balance is completely off. At this point I open up the shooting range level I made so I can begin to properly balance this weapon.

Inside of UDK.

Balancing the weapon

   The counterpart of the crossbow is the sniper rifle. They are both long range scoped weapons capable of hitting targets that are hundreds of feet away. According to my research, a crossbow such as this one is accurate up to 100 yards. The sniper can strike targets up to 256ft in game but it does suffer from significant bullet drop.

   The sniper rifle has the most range of any weapon in the game. In theory the crossbow would easily be able to match it's range but it would be too powerful. To counter the power of the crossbow I have added a longer reload time and a charge up time(something like the Torque bow from Gears of War) before the crossbow can be fired. You might think that this makes the crossbow useless but to give the crossbow another strength we also made it silent. Enemies will not be able to hear it when fired, allowing players to eliminate targets from a safe distance without the enemy players noticing anything.

  The player can carry up to 24 bullets for the sniper rifle and the reload time is a few seconds. The player can only carry 8 crossbow arrows. The arrows are almost always a one shot kill to unarmored targets and the range is effective up to about 160ft. After 160ft the crossbow arrow will begin to lose power and begin to drop quicker and quicker, losing accuracy and stopping power. The crossbow might start out with less ammunition but it has the unique distinction of being the only weapon that can have it's arrows recovered (off of walls and the bodies of slain enemies) to replenish ammo.

- Danny Q
@Dannylv100