Community Gun Fun

[TylerH]

Hi guys!

 

This is one of my earlier posts on the new forums, which shouldn't be the case as the 3rd person to have registered, but I have been a bit tied up with my existing projects.

 

Anyways, I have set out on a project to setup a nice framework (entirely in Lua) to handle various bullets, weapons, damage types, etc. so that we can start to gather an arsenal of scripted weapons that community members can use to try out some combat dynamics in their own games.

 

I am taking the first step here in having added damage, inertia, and falloff to the bullet class Josh has included with the Editor:

dofile("scripts/utilities.lua")

-- Defaults
BULLET_MAXRANGE = 500 -- Max Range for bullet movement (Def. 500 meters)
BULLET_MINDAMAGE = 5 -- Minimal damage a bullet can do. A bullet is guranteed to do this much damage (Def. 5 health units)
BULLET_DAMAGE = 15 -- Damage that the bullet would do if shot at point blank range with no falloff dampening (Def. 15 health units)
BULLET_FALLOFFBASE = 0.85 -- Range from 0 to 1, 0 being instantly to 2 being max range, for the bullet to lose damage. Values higher than 1 give the bullet more
							-- damage the farther away it gets.
BULLET_FALLOFF = 500 -- The distance falloff (Def. 500 meters)
BULLET_SPREAD = 0.0 -- The spread of the "pellets" of a single bullet (Def. 0 meters)
BULLET_INERTIA = 50.0 -- The intertia of the bullet, the amount of force transferred to the target (Def. 50 joules)

-- Variables
firstbullet=nil
lastbullet=nil

-- Bullet Table
bullets={}

-- Materials
material_impactdust=LoadMaterial("abstract::dust.mat")

-- Function to create a bullet at the given position with the given velocity
function CreateBullet( position, velocity )
local bullet = {}
bullet.position = position
bullet.velocity = velocity
bullet.origin = position:Copy()
bullet.minimal_damage = BULLET_MINDAMAGE
bullet.initialdamage = BULLET_DAMAGE
bullet.damage = BULLET_DAMAGE
bullet.falloff_base = BULLET_FALLOFFBASE
bullet.falloff_distance = BULLET_FALLOFF
bullet.inertia = BULLET_INERTIA

function bullet:Update()

end

if lastbullet==nil then
	firstbullet=bullet
	lastbullet=bullet
else
	lastbullet.next=bullet
	bullet.prev=lastbullet
end

bullets[bullet]=bullet

function bullet:Free()
	bullets[self]=nil
end

return bullet
end

-- Called per frame to update the state of all bullets in the scene
function UpdateBullets()
local bullet
local pick
local nextpos = Vec3(0)
local emitter,model
local bulletforce
local distance

for bullet,nothing in pairs(bullets) do

	-- Get the distance the bullet has traveled
	distance = PointDistance(bullet.origin,bullet.position)

	-- Our bullet has gone too far...
	if distance > BULLET_MAXRANGE then
		bullet:Free()
	end

	-- Determine where the bullet will be next frame
	nextpos.x = bullet.position.x + bullet.velocity.x / 60.0
	nextpos.y = bullet.position.y + bullet.velocity.y / 60.0
	nextpos.z = bullet.position.z + bullet.velocity.z / 60.0

	-- Perform a pick between the current bullet position and the next bullet position to see if we have hit anything
	pick = LinePick( bullet.position, nextpos )

	-- Set position to the next position
	bullet.position.x = nextpos.x
	bullet.position.y = nextpos.y
	bullet.position.z = nextpos.z

	-- Update the damage of the bullet for falloff
	bullet.damage = math.max(bullet.initialdamage * bullet.falloff_base ^ (distance / bullet.falloff_distance), bullet.minimal_damage)

	-- Check if the pick succeeded
	if pick~=nil then

		-- Create a cust impact emitter
		SetWorld(fw.transparency.world)
		emitter=CreateEmitter(5,700,pick.normal,1)
		emitter:SetVelocity( pick.normal )
		emitter:SetRadius(0.1,0.5)
		emitter:SetWaver(10)
		emitter:SetColorf(0.5,0.5,0.5,0.1)
		emitter:Paint(material_impactdust)
		emitter:SetPosition( pick.position )
		emitter:SetRotationSpeed(0.1)
		bullet:Free()
		SetWorld(fw.main.world)

		-- If we hit a model, attempt to get it
		model=GetMeshModel(pick.entity)

		-- Check if the model exists
		if model~=nil then
			-- Calculate the direction of the bullet (Normalized velocity will have a magnitude of 1, making it a unit vector telling simply direction)
			bulletforce = bullet.velocity:Normalize()	

			-- Not sure why this was commented out by Josh?
			-- Seems like it applied some kind of ricochet ability based on normal?
			--d=-Dot(pick.normal,bullet.bulletforce)
			--d=math.max(0,d)

			-- Calculate force (direction * intertia)
			bulletforce.x = bulletforce.x * bullet.inertia-- * d
			bulletforce.y = bulletforce.y * bullet.inertia-- * d
			bulletforce.z = bulletforce.z * bullet.inertia-- * d

			-- Apply bullet force
			model:AddForceAtPoint( bulletforce, pick.position )
		end

	end
end
collectgarbage()
end

 

The project will run in two phases that, granted enough participation, occur simultaneously.

 

Phase 1 of this project is aimed at FUNCTIONALITY, not APPEARANCE, and should involve mostly coders.. The goal is to how weapons implemented, minus the actual models and art associated with them.

 

What Phase 1 is going to entail is:

• Creating a basic structure to derive other things from, for example we have bullet.lua, we should strive to create a base weapon.lua, projectile.lua (Missiles, Arrows, etc.), melee.lua (Fists, Knife/Knives, Swords, etc.), and any other classes.
• Adding features and weapon properties to the base structure, including: Damage, Minimal Damage, Damage Type, Bullets Per Shot, Cycle Time, Burst Shot Count, Burst Cycle Time, Fire Modes, Falloff, Melee Damage, Melee Cycle Time, Velocity, Turning Speed (guided projectiles), Explosion Force, Explosion Radius, Grenade Time, etc.
• Implement a cyclable system (similar to the current UpdateBullets) that can receive and route information regarding hit info. This is a table of information from when a bullet hits an entity, mainly damage type, damage amount, etc. It is used in higher level game logic to provide the affect of weapons on the health of props and players.
• Specialize from the base structure, to create pistols, machine guns, sub-machine guns, rocket launchers, mounted turrets, cross bows, sniper rifles, everything imaginable.

Phase 2 is all about the art. Models, textures, emitter particles, blood decals, muzzle flashes, scope textures, accessories, etc. for the APPEARANCE of weapons should be done during this phase. This can also extend into a Phase 3, where artists and coders work together to add full animation set support to the weapon classes, support for accessories (silencers, lasers, scopes, etc.), sounds, etc.

 

The goal of the project, again, is to create a set of weapons that the whole community is allowed to use for testing and development. Coders and artists wishing to participate should be aware from the start that your code/art is intended to be released free (I am assuming Creative Commons 2.0 should be an appropriate license?) for the entire community to use.

 

Let me know what you guys think, and if feedback is positive, we can get going more on this, and I will create a WIP Thread with checklists for all 3 phases and get this going as a full on community project.

 

Cheers,

Tyler

[Scott Richmond]

Fantastic idea! This sounds like a fun project. +1 rep for you.

[TylerH]

Thanks, like I said, granted enough interest I will make it full force community, else I will just post updates and try to work on it myself.

[TylerH]

*Bump*

 

Anyone?

[Rick]

I think it's probably to early for something like this for most of us. We are still learning the power and limitations of lua with LE.

[TylerH]

*sigh*.

 

I guess I am too used to Garry's Mod, where everyone is already godlike with Lua. Too bad the Ulysses community was turned away from making a Garry's Mod remake due to the license ambiguity.

[Rick]

Well honestly I'm ok with lua, but lua with LE is a little different. With each entity being it's own lua state, it complicates sharing data between entities. There are some design things that are different and don't have anything to do with just knowing lua but instead how Josh exposed LE to lua and how he's using it.

[Josh]

Every entity does not have its own state. Every model class has its own state, which means all instances of any model share a state and can access everything about each other.

 

For communication between different kinds of models, I recommend the messaging system.

[Josh]

Regarding the weapons, I am very interested in seeing some tracers. It seems like gunfire is a combination of a lot of different things, and it's hard to pull it all together to make a convincing gunfight.

[Rick]

Every entity does not have its own state. Every model class has its own state, which means all instances of any model share a state and can access everything about each other.

 

For communication between different kinds of models, I recommend the messaging system.

 

 

I think you are going to find that the messaging system doesn't handle every situation. Sometimes entity communication with each other needs to be more advanced than just sending messages to each other.

[Josh]

Can you give an example?

[TylerH]

Well, SendMessage is clearly failing me in sending damage integers or a table of hit info...

[Josh]

You can send the damage value as a string. What is the hit info thing you are talking about?

[TylerH]

Hit info is just a Lua table with a few values in it. Like the attacking player, damage type, damage amount, etc.