Mortar shooting

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#1

Hello dev forums! I’m currently making a mortar type shooting system for a person in my game, but I’m wondering how would I achieve making a part launch into the air and do a ^ type shape in the air then coming down

image
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somewhat like this, if there’s a way you know which can allow it to be anchored it would help the most

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#2

Use vector forces. They do the physics work for ya.

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#3

I mean, how i think mortars work in real life is literally just a big round fired into the air and the force of gravity making them do parabolic movement, so the most basic and simple way of doing this is to shoot an unanchored projectile upwards, and mess with the force and density values of the projectile until you find what you want? :man_shrugging:

Cause otherwise If you want an anchored projectile i think you would have to dive into parabolic equations to calculate the movement.

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#4

The issue is the the character that shoots it is small and the player is big, the player might be able to effect it, also how would I do this?

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#5

Im new to vector forces how would I achieve this?

#6

Ohhh, so you’re making kind of like an RTS? like the conquerors? yeah in that case anchored is the way to go.

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#7

“i think you would have to dive into parabolic equations to calculate the movement.”, I’
m a bit taken back from this statement, I’m not sure how to do this

#8

honestly can disable collisions between the player and projectiles using physics service

#9

yeah exactly (extra few words)

#10

but then other parts like roofs or invisible barriers

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#11

Yeah its going to be an issue if you do it unanchored, cause what if you’re shooting a target thats moving away, or theres objects in the path? and even if you take all of that into account, relying on unanchored object physics is still iffy.

Im not very sure myself, as I’m not really good at physics. But I’ll get back to you if I find a solution

#12

Thank you! I’ll happily wait for that responce

#13

Hello there, its been quite some time since I first came across this thread, but I learned how to do this recently and figured I should share it!

I made a module that makes it as easy as this:

local movement = require(script.movement)

local start = part.Position
local to = Goal.Position
local angle = 45 --in degrees
local velocity = 25 --initial speed
local playlength = 2 --how long the movement tween plays for
	
movement.parabola(part,start,to,angle,velocity,playlength)

Where all you need to know is that the value for “velocity” is the speed it gets launched at from an “angle” value.

image
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essentially simplifying the formulas that you see on the image.

And heres how that looks like:


parabolic_part.rbxm (4.8 KB)

The simplified version of how it works is that using the proyectile motion formulas we determine the Y position of the projectile in an instant in time “t”. And we calculate the flight time (time the projectile is in the air) in order to use it in a loop so it iterates until the current time >= flight time, which is when the projectile has reached its destination. Heres the module:

local ts = game:GetService('TweenService')

local module = {}

function  module.parabola(object:BasePart,From:Vector3,To:Vector3,angle:number,velocity:number,playlength:number)
	local args = {object,From,To,angle,velocity,playlength}
	for i=1,#args do assert(args[i],'Err: Missing argument '..i) end
	
	local t,g = 0,9.8 --time and gravity
	
	-- Final and Starting positions
	local XZf,XZo = Vector3.new(To.X,0,To.Z),Vector3.new(From.X,0,From.Z)
	local Yf,Yo = To.Y,From.Y

	--Calculating Velocities
	local Voy = velocity*math.sin(math.rad(angle)) --Initial velocity in Y
	local ft = (math.sqrt(2*g*Yo-2*g*Yf+Voy^2)+Voy)/g --calculating flight time / max air time
	local Vxz = (XZf-XZo)/ft --Velocity in X and Z

	--functions to get position with respect to time y(t) xz(t)
	local ypos = function(t) return Yo + Voy*t - 1/2*g*t^2 end
	local xzpos = function(t) return XZo + Vxz*t end
	local V3pos = function(t) --return position in a vector3
		local xz = xzpos(t)
		local y = ypos(t)
		return Vector3.new(xz.X,y,xz.Z) 
	end
	
	--stuff for tweening / animating, for custom playbackspeed.
	local tinfo = TweenInfo.new(playlength,Enum.EasingStyle.Linear)
	local twt = Instance.new('NumberValue',script)
	local tween = ts:Create(twt,tinfo,{Value=ft})
	local run = true
	local cn

	tween:Play()
	cn=tween.Completed:Connect(function() cn:Disconnect() run = false end)

	while task.wait() and run do --position loop
		t = twt.Value
		object.CFrame = CFrame.new(V3pos(t),V3pos(t+.1))
	end

	twt:Destroy()
	print('completed movement')
end

return module
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