Week 7: Guns & Perks

This week's development has consisted of evolving the base mechanics that I created in week 3.

Areas of development:

• Revamped weapon wall buy system

• 'Mystery box' mechanic

• Base perk system with scalability built in for future upgrades

• Perk machine asset changes

• Gun Damage Pass & Headshot Logic

My week started with revamping the individual wall buy weapons. The idea of this mechanic is that the player can find specific weapons with the level. The player will be able to buy them using the points they have acquired. The initial system that I created did work as intended but the code behind the scenes wasn't very user-friendly. Due to this, I wanted to change the system so it would be easier to use and scale. This process would prove very useful as I was able to use the same approach for the 'mystery box' mechanic.

Changes made:

I changed the system from using individual actors for each buyable weapon. The system is now a single actor that will update the chosen gun mesh and gun ID within the construction script by using a public instanced variable. This lets me easily change which weapons will be in the level on a per-actor basis.

Mystery Box

This mechanic is very reminiscent of the original mechanic from the Call of Duty franchise. The player can spend their points to open the box. Once opened it will randomly choose an available weapon. The player can then choose to take the weapon or let the box close after an amount of time. This lets the player unlock weapons that otherwise would be inaccessible. It gives the player progression a degree of randomness which helps give the game more variation. The next stages of this mechanic will be to add VFX and SFX to help give it the extra juice to make it more interactive.

Core Perks

The next part of this week's development involved the perk system. I started with creating an enumerator that will help determine which machine is for which perk. I then created a variable for that enum and allowed it to be instance editable. This allows me to change the perk machine with a single button press. This also means that all of the logic is within a single actor which helps streamline the development process.

When the player interacts with the machine it will check if it can be purchased, similar to other interactable mechanics. It will then change the flow of the code depending on which machine was interacted with.

This picture shows the health perk logic however each perk is structured in the same way. I made a new blueprint interface to send 'messages' to the player character. I am using a switch on int node which uses a local ID to determine the tier of the perk that has been purchased. After each purchase, it will increase the ID index so that the next purchase will give the next upgrade to the player. This will also update the purchase cost to make sure that the next upgrade is more expensive. I have also made these variables instance editable to change them on a per-actor basis. Each of the messages that are sent to the player character will then run an event which is how the effect of the perks are being applied to the character.

I started with creating the functionality for the base tier of the perks and will then develop the upgrades for the perks next week. With the system I have created, once I have the actual perk effect logic created for the player it will just need to be called once the correct perk tier is purchased.

Base Perk tiers (all working in game)

• Health Perk: Increases the player's base health from 150 to 250

• Extra Life Perk: If the player reaches 0 health, instead of dying they will be instantly revived back to full health. (All perks will be removed)

• Agility Perk: Increases reload speed by 50%

• Damage Perk: Increases all gun damage by 50%
  

Perk machine Asset

The mesh that I used for the perk machine was created by an artist who supplied their work for free on Sketchfab. For my game, I have different types of perks that give different effects as mentioned previously. With this in mind, I wanted to be able to tell the perk machines apart so they can be easily distinguished by the player in the game. The model I downloaded from sketchfab didn't have any material channels that could be easily customized so I took the model into substance painter to make some edits myself. I am by know means an artist myself when it comes to things like this and appreciate that the methods used are probably very wrong but I'm happy with my results in the end.

I started by creating a new layer on the base color and then simply painting on the UV maps to cover the places that I wanted to change.

I then applied an HSL Perceprive filter to the layer which allows me to change the colour of the entire layer. This meant that I could quickly change the colour, export the base colour, and use it in Unreal. This whole process did mean that I lost some of the detail that I painted over but I am much more happy with the outcome.

Original:

New: (With a bit of coloured lighting added to the front)

Base gun damage pass:

The guns up to this point didn't have any changes to the damage values. They were all the same across the board which meant that no gun was more powerful than the other in terms of damage per hit. I spent some time considering the ammo amount, fire rate, and overall gun design to dictate how much damage each gun should deal per hit. As all of the gun stats are within a data table it's very quick and easy to make changes to my gun system. Once I start fully playtesting the build I will be able ti further tweak the guns where necessary.

Headshots:

Now that each gun has its own damage values, I needed a way to reward player skill. One of the most common ways this is done in shooter games is getting headshots. When the player gets a headshot it will apply a headshot modifier to their damage. This gives more incentive for the player to shoot for the head as they will deal more damage per bullet. Each gun has its own headshot modifier, further exapanding the uniqueness of each gun. Also if the player kills a zombie with a headshot blow it will reward them with more points for that kill. In the earlier rounds a player may be inclined to get more body shots to acquire more points but then going form headshots in the later rounds to get easier kills while also using less ammo.

With the line trace that the player 'shoots', it can check the nearest bone that was hit on the skeletal mesh. all of the logic will run for the headshot if the 'head' bone is hit.

Week 7 notes:

Zombie AI updates

I needed to make some additions to the AI to make them 'enter' the map. I started with making a new blueprint actor for the barriers.

I created some new tasks for the behaviour tree.

1. Get a reference to the nearest accessible window actor.

2. Attack the window

3. Enter the window if the window is destroyed

Once everything has been run from this selector it will then default to the chase player logic. This does give the intended outcome of allowing the zombies to spawn outside of the map. hit a barrier and then enter the map however, I'm not entirely happy with the results yet so it will need much more development time.

Zombie models:

I added a construction script to the zombie actor which will randomly choose a zombie model when it spawns.

My plans for next week is to optimize the level. I aim to get the perk system and all of the tiers finalised and hopefully do some more playtesting.