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SIP Brief

Ballista-Based Travel in Video Games

Team Members: Rhiannon Holloway, Game Design Major

Last Updated: 07/11/2021

Technical Field

This project involves the technical fields of Game Design and Game Programming.

Background Information

The idea for this mechanic came from a game idea I imagined where players play as ants, and they have to assassinate target humans. The game idea was loosely based on a dream I once had. This mechanic could be useful for a game like that as it would give tiny players a way to reach the human targets. It could be useful for other games too as a way of travel and attacking enemies. For sci fi and fantasy games, sometimes the ground is broken up and levitating. This could work as a new way of traveling between areas and dealing damage to enemies. The game mechanic evolved and changed a bit as the gameplay mechanic progressed.

Prior Art for Ballista

For ballistas, they should be alright to create game models for as they are ancient devices. The type of ballista being shown in the game is similar to a Roman Ballista. A prior art existed for a modern ballista machine gun, but the ballistas in the game are closer to ancient ones. There was also an Oculus game called Ballista, but in that players use a ballista that is more like a slingshot. They use the slingshot ballista to shoot creatures to destroy objects; such as buildings. It does not appear to be a travel mechanism for the player. The targeting is planned to be similar to archery in games with 3D environments; such as the 3D Legend of Zelda games. A Prior Art patent was discovered for both a Wii archery apparatus and a similar device that was not for the Wii. However, I did not find one specifically for generic archery mechanics. If generic archery mechanics were copyrighted, many games would have to figure out different ways to create archery mechanics or just scrap the idea altogether. Therefore, it should be alright to use a similar targeting mechanic to archery targeting found in many games.

Project Description

I planned on creating a game mechanic that functions as a travel system where players ride a spear that is shot out by a ballista-like device. Players can target the spear towards enemies or land. For instance, a player can shoot at a mountain, and the spear would shoot towards it. Then, players would get off of the arrow when it landed. With a few modifications, it could also be used to deal damage to enemies. It could be used to injure one giant enemy by shooting the spear at them. The camera follows the spear. The player can shoot the spear after mounting it. The ballista model currently is shown moving as the player, but I hope to fix that after the initial prototype.

Innovation Claim

This project is innovative, because it fuses a travel mechanic with an eventual attack mechanic. Roman Ballistas are also not often used in video games, so this will also spread knowledge of this type of ballista.

Usage Scenario

The demographic who might want to use this mechanic includes game designers and developers who want to have small characters or characters with cartoon physics. This can include things such as a human in a giant’s world, an ant in a human world, players controlling tiny robots or drones, and levels where players are shrunk down in size. I hope to improve its current design to allow for player attacks as well. The ballista can also be modified to function as purely an attack mechanic if players do not ride the spears. Using a ballista purely as a weapon could help add extra gameplay features to cartoon games or be modified physics-wise for more realistic historical games. Some designers and developers may be able to modify the targeting mechanic to add to other gameplay features and mechanics.

Evaluation Criteria

The following questions fit the criteria for evaluating the project:

●   Does the camera follow the player while they are on the ballista spear?

●   Can players mount and dismount the ballista?

●   Are players able to target an area and have the ballista hit the targeted area?

●   Do players stay on the spear properly for the duration of the travel?

●   Does the spear properly stick in the environment (no clipping through the ground?)

●   Does the player character get off of the spear after they have arrived at the targeted location?

●   Can the ballista be upgraded eventually?

Possible Future Project Goals (Post-Prototype):

I hope to eventually:

  • Fix any current bugs in the prototype

  • Add attack mechanics

  • Have the enemy AI follow the player and be destroyable

  • Add scripted upgrades to the talent tree UI

Objectives and Tasks Associated with the Project

Objective 1: Creating Ballista Mechanic

  1. Models were created in Blender. These were the base models with collision to show the mechanic in action and the environment. A basic ballista model and spear model need to be created as well as slightly different ones for upgraded ballistas and spears. 

  2. A title screen was created that can take players to one or more test level(s).

  3. I created a shooting animation and tried to parent the player to the ballista's spear.

Objective 2: Creating Upgradable Ballistas for Future

  1. Different ballistas need to be scripted properly. They will have different amounts of damage, speed, and amount of distance a player can reach.

  2. I created the UI for the talent tree. It needs to be scripted though.

  3. Models need to be changed if a ballista gets swapped out or upgraded.

  4. All ballistas need to be tested to ensure they are all working.

Description of Design Prototype 

The design prototype was built using Unity. The ballista model was made in Blender. It is playable on PCs in Unity. When the prototype is finished, the game should be able to open to a basic level where players can use the ballista and target where they want to aim. Enemy AIs should be programmed in so players can kill the targets and try to gain skill points and choose what attributes that they want to add to their ballista. There will be basic models to test out the game's physics and collision.

Evaluation Plan

The game mechanic should be evaluated by a few individuals familiar with general PC gaming controls. The game mechanic will be judged on its ability to run smoothly and by how well it met the promised game mechanics. The ground should have proper collision, enemies should be able to be killed, and the player should also be able to take damage. The ballista will  have a basic model and animation and the targeting system should work correctly. Players will be able to try to target an area. Where they target will be represented by a red target symbol until the player presses a button to actually shoot the spear. The target icon needs to line up so that the ballista spear can have some player input and control. Basic controls need to work, and the project needs to be evaluated to ensure it is not too buggy. Testers should also test to make sure the skill tree for upgrading the ballista works. The upgraded ballista should have a different color and different attributes depending upon which ballista the testers choose.

Project Completion Assessment Progress:

  • Created Test Environment

  • Created Image for Title Screen

  • Created Player Movement

  • Created Player Mounted Ballista

  • Updated SIP Brief

  • Created Working Title Screen

  • Created Ballista Shooting Animation​

  • Created Shooting Mechanics

  • Debugging Parented Player and Spear Scripts

Appendices & Prior Art

김범 (2019).System for Gaming Archery.  KR20030070182A. Retrieved from https://patents.google.com/patent/KR20030070182A/en?oq=KR20030070182A 

吴巧云 (2019). Bow and arrow combination of video game. CN201755403U. Retrieved from https://patents.google.com/patent/CN201755403U/en?oq=CN201755403U 

Bos, M. (2019). Arrow signs photo. Retrieved from https://unsplash.com/photos/4eBOAeFfY0w 

Brackeys. (2017, November 29). START MENU Tutorial in Unity. YouTube. https://www.youtube.com/watch?v=zc8ac_qUXQY&t=634s. 

Brackeys. (2020). Third Person Movement in Unity. YouTube. https://www.youtube.com/watch?v=4HpC--2iowE. 

Cinemachine for Unity

Document Version of SIP Brief. 

Dariatus Tutorials. (2020, July 29). Simple Mounting System Tutorial in Unity. YouTube. https://www.youtube.com/watch?v=YQwZDzZrjZc&t=586s.

Foresman, P. S. (2014). Roman soldiers using ballista. Retrieved from https://commons.wikimedia.org/wiki/File:Ballista_(PSF)_vector.svg 

High Voltage Software. (2019). [Oculus video game].Retrieved from https://www.oculus.com/experiences/quest/1611681078875316/?locale=en_GB 

in-Scope Studios. (2019, October 5). #31.0 Unity RPG Tutorial - Talent tree UI. YouTube. https://www.youtube.com/watch?v=L9Wqtk1qVOU.

Kachanovsky, N. (2017). White Sony PS4 DualShock controller over person's palm. Retrieved from https://unsplash.com/photos/FJFPuE1MAOM 

Game Textures from Textures.com

Image of Wooden Ballista Concept Art. WoodenBallista.jpg

Image of Intended Targeting System. TargetSystem.png

Image of Upgradable Skill Tree.  Upgradable Ballista Skill Tree.png. 

Logos created for Skill tree.

Manuel, A. (1914). ES57335A1. ES57335A1. Retrieved from https://patents.google.com/patent/ES57335A1/en?q=ballista&oq=ballista+

Recorded in-game Ballista Mechanic Gameplay Clips

Video of Basic Prototype Ballista for Testing .Video.

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