Dexter Abrisius
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Gameplay Programmer
Specialization - Shooting
Time: 7 weeks, 20 h/week
The goal of my specialization was to create a third person shooting system with modular weapons. Part of the vision was to develop a generalized weapon system with easily interchangable parts that enable the rapid implementation of different firearms.
I chose to combine my specialization with Game Project 7. This effectively meant that I worked on the shooting and weapon systems of P7 during my specialization time. This meant I didn't need to spend time on parts of the demo not relevant to my specialization, such as assets and animations, as I already had a project I could insert my specialization into.
The Weapons
An important part of my specialization was to create a weapon system that allows for easy implementation of new firearms. I consider this part a success, as adding new weapons was much quicker and easier than I had planned. Once I had created my variables and functions I simply needed to change some numbers to create different weapon versions. The only real effort i spent on making new guns was in the creation of new behavior like that of the minigun.
The weapons I created were, in order: a revolver, shotgun, assault rifle, submachine gun, sniper rifle, and rev-up minigun.
The Revolver
I began by creating the revolver as a base class for my weapons as it was a fairly versatile gun that would translate into the other firearms well. The first mechanic I added was shooting, in the form of a raycast that was visualized by a line. Next I added fire rate, then ammo and reloading.
Bullet Origins and Pointing Bullets towards the Crosshair
I made the bullets originate from the actual gun position rather than just the camera. The purpose for this is, for example, that if the player wanted to shoot out of a window but had the gun positioned below the frame, the ray from the gun would intersect with the wall. It also meant that blood splatter VFX could be angled along with the acual direction of the gunshots.
The way I accomplished this is by raycasting from the camera straight forward (see the blue line on the picture to the right). If the camera ray would intersect with an object, a second raycast from the gun joint on the player mesh would be drawn to the collision point.
The Shotgun
The second firearm I implemented was the shotgun as it was a good vessel for the creation and testing of the projectile spread system.
I was able to use the shotgun to test the inaccuracy variable by making the shotgun shoot hundreds of pellets at once, showing me the clear boundaries of where shots could spread to and how they were likely to distribute themselves.
.json Weapon Statistics Tool
In preparation for adding more weapons I created a quick and basic tool in the form of .json text files. The purpose of this was to simplify the creation of new guns and to make it accessible for designers without them needing to access the code.
After the first time a .json has been read the program converts it into a binary file, meaning that the game loads the files faster after it has been run once.
Assault Rifle, Submachine Gun, and Sniper Rifle
Implementing the assault rifle, submachine gun, and sniper rifle was much quicker than I had expected. By this point my weapons were versatile enough that creating new weapons simply meant changing some variables.
In order to add differentiation between the weapons I added a movement speed modifier when the player is aiming. The revolver and submachine gun only slows the player a little, while the sniper rifle punishes movement heavily.
The Minigun
The final and most unique weapon I added was a rev-up minigun, which meant I needed to add a system for increasing a firearm's shooting speed as it fires. I also made it start spinning/revving up instead of aiming when the aim button is held, meaning it always hip-fires.
The raycasting for gunshots. The blue ray is coming from the camera and goes along the camera's forward direction. The yellow ray is shot from the gun to the camera ray's collision point
The revolver's .json file
Weapon Characteristics
Each weapon's strengths and weaknesses encourages the usage of every one of them depending on the situation or the player's playstyle:
The sniper rifle has perfect precision and high damage at long range, but is slow and lacks sustained damage if the player misses.
The revolver has high accuracy and movement speed, but is outperformed by the sniper rifle at long range and the submachine gun at short range, and suffers heavily from recoil.
The assult rifle has a large magazine and great sustained damage, but doesn't boast the same opportunities for an instant kill as the sniper rifle or shotgun offers.
The submachine gun offers faster firing speed and movement speed than the assault rifle, but with a smaller magazine it gives less sustained damage.
The shotgun can kill an enemy in a single shot at short range and has comparatively little recoil, but it has high initial inaccuracy and only offers two shots per magazine.
The minigun has the highest sustained damage and an immensely large magazine, but its slow movement speed, poor initial fire rate, and high inaccuracy forces the player to prepare for fights ahead of time and encourages a more defensive playstyle.
Reflection
I am satisfied about the selection of weapons implemented in the project. The core types of firearms are all covered, and they each offer a valid reason to use each of them. Moreover the versatility of the weapon system allows for easy and rapid implementation of new weapons. The end result is a solid shooting system with a respectable selection of weapons that has room to grow and be iterated upon if more time is spent on the project.
Future Improvements
The most clearly lacking aspect of my work is the "game juice" or feeling of the shooting. Because I wanted to focus on implementing gameplay features I did not spend much time on the aesthetics or feedback of the gunplay. Adding something like health bars, camera focus when aiming, and generally polishing the feeling of the combat would improve the player experience significantly.
By implementing a way to inspect the stats of firearms and to choose between them I could open up the possibility of creating many more weapons in a short amount of time as I could rely on the same systems that already exist for the weapons currently in the game.
To add more fun and variation to the guns I would also have liked to implement more unique weapons that behave differently from the existing ones.
The Weapons
An important part of my specialization was to create a weapon system that allows for easy implementation of new firearms. I consider this part a success, as adding new weapons was much quicker and easier than I had planned. Once I had created my base variables and functions I simply needed to change some numbers to create new weapon versions. The only firearms that took real effort to create were the shotgun and the minigun as those had unique functionality compared to the rest of the guns.
The weapons I created were, in order: a revolver, shotgun, assault rifle, submachine gun, sniper rifle, and rev-up minigun.
The Weapon Base Class
I begun by creating a base class for my weapons that I named RangedWeapon. My original idea was to create a subclass for each of the guns, but I found that my code was versatile enough that I only needed a subclass for the minigun. I based the first iteration of RangedWeapon on the revolver, effectively meaning that the revolver was the first weapon I implemented. This was because I needed the revolver for P7, so it was my most urgent weapon to implement, and it was fairly versatile choice that would translate into the other firearms well.
Shooting
The first mechanic I added to RangedWeapon was shooting, in the form of a raycast that was visualized by a line. Next I added fire rate, then ammo and reloading. An interesting thing I implemented in the shooting is that the bullets originate from the actual gun position rather than simply the camera. I achieved this by raycasting from the camera straight forward (see the blue line on the picture to the right). If the camera ray would intersect with an object, a second raycast from the gun joint on the player mesh would be drawn to the collision point. The purpose for this is, for example, that if the player wanted to shoot out of a window but had the gun positioned below the frame, the ray from the gun would intersect with the wall. It also meant that blood splatter VFX could be angled along with the acual direction of the gunshots.
The Shotgun
The next gun I implemented was the shotgun. Again this was because P7 needed it. Had I made the weapon system completely independent from the group project I would have created the other conventional guns first, those being the assault rifle, submachine gun, and sniper rifle. Still, the shotgun let me create and test the inaccuracy system very easily as the lines drawn from the shotgun clearly displayed the directions the shots were able to go in. Additionally, I was able to further test the inaccuracy spread by making the shotgun shoot hundreds of projectiles at once, which essentially gave me a heat map of the shot density as it showed me where the projectiles were statistically more likely to hit and the clear boundaries of where the shots could spread to.
.json Weapon Statistics Tool
At this point, having created two weapons and validated that the player was able to use several weapons, I created a quick and basic tool for creating new weapons in the form of .json text files. The purpose of this was to simplify the creation of new guns and to make it accessible for designers without needing them to access the code. After the first time a .json has been read the program converts it into a binary file, meaning that the game loads the files faster after it has been run once.
Assault Rifle, Submachine Gun, and Sniper Rifle
Implementing the assault rifle, submachine gun, and sniper rifle was much quicker than I had expected. By this point my weapons were versatile enough that creating new weapons simply meant changing some variables. However, to add some uniqueness between the weapons I implemented a movement speed modifier when moving. Thus I could make different weapons lower the movement penalty by different amounts, creating more reason to use the revolver or submachine gun instead of the assault rifle. Likewise I made the sniper rifle slow down the player more than any other weapon while aiming, and made its hipfire inaccuracy very high. This gave the player more reason to use each weapon in different situations and helped prevent the weapons from feeling overly similar to each other.
The Minigun
The final and most unique weapon I added was a rev-up minigun, which meant I needed to add a system for increasing a firearm's shooting speed as it fires. Moreover, the minigun was designed to be a heavy weapon for dealing maximal damage with the proper setup. Therefore, the gun penalizes the player with lower movement speed even when simply carrying the weapon, and it has the worst accuracy in the game as it can only hip fire; Instead of aiming, the minigun starts spinning when the aim button is held. This means that the player can prepare for a shootout without needing to spend bullets to do so, but the movement speed penalty from doing so encourages the player to position themselves correctly before starting to spin the barrel.
Weapon Characteristics
Each weapon's strengths and weaknesses encourages the usage of every one of them depending on the situation or the player's playstyle:
The sniper rifle has perfect precision and high damage at long range, but is slow and lacks sustained damage if the player misses.
The revolver has high accuracy and movement speed, but is outperformed by the sniper rifle at long range and the submachine gun at short range, and suffers heavily from recoil.
The assult rifle has a large magazine and great sustained damage, but doesn't boast the same opportunities for an instant kill as the sniper rifle or shotgun offers.
The submachine gun offers faster firing speed and movement speed than the assault rifle, but with a smaller magazine it gives less sustained damage.
The shotgun can kill an enemy in a single shot at short range and has comparatively little recoil, but it has high initial inaccuracy and only offers two shots per magazine.
The minigun has the highest sustained damage and an immensely large magazine, but its slow movement speed, poor initial fire rate, and high inaccuracy forces the player to prepare for fights ahead of time and encourages a more defensive playstyle.
Reflection
I am satisfied about the selection of weapons implemented in the project. The core types of firearms are all covered by the ones featured in the game, and they each offer a valid reason to use each of them. Moreover the versatility of the weapon system allows for easy and rapid implementation of new weapons. The end result is a solid shooting system with a respectable selection of weapons that has room to grow and be iterated upon if more time is spent on the project.
Future Improvements
If I was to improve upon the list of weapons I would have liked to create more options for each category of weapon. It is common nowaday to see a large selection of similar guns of the same category, with small changes in stats appealing to different players. By implementing a way to inspect the stats of firearms and to choose between them I would open up the possibility of creating many more weapons in a short amount of time as I could rely on the same systems that already exist for the weapons currently in the game. It would also be interesting to create a weapon modification system that could give small changes to the statistics of guns to further increase the player's opportunity for customizing their playstyle.
I would also have liked to implement more unique weapons, like something that shoots a slow, explosive projectile or a continuous laser beam. This would provide more variety to the player's arsenal and would improve the ability to choose the right weapon for the right situation. An explosive weapon would work great when fighting several enemies at once or against an enemy that is hard to hit. A laser beam could be a weapon with decent sustained damage and perfect accuracy that would be a good option for fighting at long range for a player that isn't skilled enough at aiming to use a sniper rifle. Most importantly, unique weapons would be a fun break from the more commonplace firearms that already exist in many other games and would give an enjoyable twist to the game's shooting system.
The raycasting for gunshots. The blue ray is coming from the camera and goes along the camera's forward direction. The yellow ray is shot from the gun to the camera ray's collision point
The revolver's .json file
Assault rifle
Submachine gun
Sniper rifle
Minigun
Shotgun
Recoil and Inaccuracy
Because I wanted to create a shooting system that would be applicable to both third person shooters and first person shooters I decided to go for a hybrid approach when it comes to recoil. When the player hip-fires, bullets are spread in a cone. However, if the player is aiming the camera shakes instead.
This creates a versatile recoil system that can be used in most types of games. Because it is made of two parts it would also be possible to use only conical spread or only camera shake if a game wanted to use a single system.
Conical Bullet Spread
When the player shoots while hip-firing the angle of the cone inaccuracy grows. The code for the bullet spread is a fairly simple randomized alteration of the projectile's direction.
Recovering from Conical Recoil
After the player stops firing for a while the cone recoil recovers exponentially. The recovery scale with the recoil per shot, meaning that the sniper has higher recoil recovery because it has high recoil.
To calculate how fast I wanted the recoil recovery to be I used Geogebra to set up a graph function. This showed me how much recoil the player would have depending on how many shots they fired, and how fast it would recover.
Camera Shake recoil
The player suffers no bullet spread inaccuracy when it is aiming. Instead, the camera jumps randomly upwards and horizontally. The variables for the amount of camera shake is separate for the horizontal and vertical jump. The camera shake is randomized between 0.5x-1x the max vertical jump upwards and -0.5x-0.5x the horizontal.
Although some games use spread patterns for weapons, I chose to make the recoil completely random as it provides a more dynamic experience. Although random recoil gives more of a challenge when attempting to hit a target, it is still predictable enough that a skilled player can adjust their aim to maintain their precision.
Accuracy when Moving, or Hip-firing
When the player moves or hip-fires it has lower accuracy than when it is aiming, depending on the characteristics of the held weapon. For example, the revolver and submachine gun are far less punishing than the sniper rifle.
Syncing the HUD with Accuracy
In order to sync the player's accuracy with the crosshair I made a version of the shotgun that shoots projectiles that go in the cardinal directions of the player's recoil. Thanks to this was able to adjust how separated the crosshair was by studing how the projectiles lined up with the HUD.
Future Improvements
Adjusting one's aim to keep the crosshair on a target while the recoil is kicking around the camera can sometimes feel disorienting. This is the most obvious part of the recoil system that requires fine tuning and polish. The interaction between the camera shake and the player input could be improved, and it would also be nice if the camera would lower itself again after the player has stopped firing. However, this would need a lot of tweaking to get right as I would need to account for the player's mouse movement and how it interacts with the recoil. Although I decided to focus on other tasks for my specialization, further work on the camera shake recoil would be necessary to deliver a quality product.
The recoil increases as the gun fires, causing it to become more and more inaccurate.
The camera shake is randomized between 0.5x-1x the max vertical amount upwards and -0.5x-0.5x the horizontal.
Shooting Range
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Credits
Because my specialization uses Game Project 7 as a base I want to give credit to my team. I developed the player and all features discussed in my specialization by myself, but the engine and features not relevant to the specialization project was developed as a group. The level where I showcase my weapons was made by myself in Unreal Engine and exported to our own engine.
dexter@abrisius.se
+46 72 172 70 66