I need some insight on a feature I’m trying to add to a combat system I’m making. I want to add a “knockback system” and the ways that I’ve tried to do so haven’t worked.
To clarify, I want both the attacker and the victim to be moving. When the player hits the victim, the victim will move back a bit and the player will advance towards the victim to continue the combo.
Things I've Tried So Far
I’ve tried two things so far,
Changing Velocity of the HumanoidRootParts
-- Basic Idea, not actual code
local HitHRP = hit.Parent.HumanoidRootPart
local PlrHRP = plr.Character.HumanoidRootPart
HitHRP.Anchored = true
HitHRP.Velocity = PlrHRP.CFrame.lookVector*45
PlrHRP.Velocity = PlrHRP.CFrame.lookVector*45
HitHRP.Anchored = false
This approach kinda worked. The knockback was delayed on the victim, but it still moved the player. On the other hand, the player didn’t move at all. No clue why.
Adding BodyVelocity Objects
-- Basic Idea, not actual code
local HitHRP = hit.Parent.HumanoidRootPart
local PlrHRP = plr.Character.HumanoidRootPart
HitHRP.Anchored = true
local HitBV = Instance.new("BodyVelocity")
HitBV .MaxForce = Vector3.new(math.huge, math.huge, math.huge)
HitBV .P = 100
HitBV .Velocity = PlrHRP.CFrame.lookVector*45
local PlrBV = HitBV:Clone()
HitBV.Parent = HitHRP
PlrBV.Parent = PlrHRP
game.Debris:AddItem(HitBV, .5)
game.Debris:AddItem(PlrBV, .5)
HitHRP.Anchored = false
This approach didn’t work at all, neither the player or the victim moved.
I don’t know whether my attempts were implemented wrong or if something else is going on behind the scenes.
Hopefully, someone can give me an idea on how to best add this “knockback system”
Just something quick. You do know that the variable that holds your bodyvelocity is named “HitBV” and when you try to reference it you use “BV” for some reason. Instead of HitBV.Velocity you use BV.Velocity
edit: Don’t know if your real code has that problem. but this code right here has it. Also, I usually set the P value to math.huge
local Speed = 40
local Force = 80000
local TotalForce = Force
local KnockBack = Instance.new("BodyVelocity")
KnockBack.Parent = part.Parent:FindFirstChild("HumanoidRootPart")--part is the target of the knockback/ the opponent
KnockBack.MaxForce = Vector3.new(TotalForce,TotalForce,TotalForce)
KnockBack.Velocity = Character:FindFirstChild("HumanoidRootPart").CFrame.LookVector * Speed -- based on the direction YOUR character is facing.
This is how I made my knockback, hope it helps, even if its crude.
Just want to note that, P on BodyMovers also takes into account the mass of the entire object they are moving. So you’ll either want to make the object Massless or take into account the mass of the object.
To be honest you might prefer to use the AssemblyLinearVelocity from the client’s perspective, which is way better than bodyvelocity
Edit:
if you need help regarding it, it’s a value inside every part, I usually add a remote event which triggers a local scripts with a text similar to:
(naturally VECTOR3 is a vector3 from the server script which triggers the knockback if you’re trying to add knockback, however you don’t have to use a vector3 from outside the script if you feel like the knockback is always gonna be the same, even if I think it’s really unlikely)
also sorry for the many edits and mistakes, it’s the first time I post something on the forum please be merciful lol
The velocity you want the player to have, for example if I want him to go fly up I’d put:
game:GetService(“Players”).LocalPlayer.Character.HumanoidRootPart.AssemblyLinearVelocity = Vector3.new(0,100,0)
However this is only if you don’t another player to trigger it, in which case you should use a remote event to trigger it and put the variable inside it, so unless you want the player who uses the script to trigger it you should just leave it as it is.
(if you don’t know what a event is I suggest you look it up and watch a tutorial)
You can replace that hit character line with this:
local upForce = Vector3.new(0, 250, 0) -- Replace 250 with whatever value works
local knockbackForce = caster.HumanoidRootPart.CFrame.LookVector * 1000 -- Replace 1000 with your value
hitcharacter.HumanoidRootPart:ApplyImpulse(knockbackForce + upForce)
What this code does is first get the vector for the upForce. This is what will knock the enemy character upward. That 250 is the force applied, NOT the velocity. Second, it gets the knockbackForce. This is the direction the caster is facing, multiplied by the force. Change it to your liking. Lastly it combines the knockback and the up force and applies it to the character. This is what will move the character.
use CFrame.LookVector of the attacker, for example
the force of your function would look like this:
force = caster.HumanoidRootPart.CFrame.LookVector*Vector3.new(200,0,200)
^ if the Caster is a character object and you want the player to be knockbacked in front of them with a speed of 200 and without moving upwards or downwards.
