Making a bullet spawn from a certain point while maintaining it's direction

[BetterCallBrenda (Nancy)]

In my game, I send the center of the screen to the server and fire projectiles based off of that.
Client

local currentCamera = workspace.CurrentCamera
local VIEWPORT_SIZE = currentCamera.ViewportSize
local unitRay = currentCamera:ViewportPointToRay(VIEWPORT_SIZE.X / 2, VIEWPORT_SIZE.Y / 2)
module.abilityEvent:FireServer("PrimaryFire", {unitRay.Direction, unitRay.Origin})

The server then handles the damage dealing and fires an event to the clients to handle the projectile.

Server

local simBullet = myCaster:Fire(origin, direction, weaponAttributes["Bullet_Speed"], CastBehavior)
RS.Remotes.visualEffect:FireAllClients({'ViviPrimary', myPlayer, origin, direction, weaponAttributes["Bullet_Speed"], weaponAttributes["Max_Distance"], myBools["Enchantment"]})

Client

myCaster:Fire(origin,direction,soeed,castBehaviour)

This is fine for actual gameplay, as the bullets go exactly where I want them to.
https://i.gyazo.com/b10600959ce12945fbedae9817ee23f6.gif

However visually I would want the bullet to spawn from somewhere else while still going in the same location. (For the example I would like it to spawn from the character’s right hand) However when I do this it messes up the trajectory. How would I be able to do this so it’s still accurate to what’s actually happening on the server?
https://i.gyazo.com/24dc369e9ab6e5b68670ccc3ea891014.gif

I am also using Fastcast if that plays into anything.

[Prototrode (Vernumerator)]

First we need to find the focal point. This can be done by casting a ray at the mouse’s location and getting its hit position. If it doesn’t hit anything, we can calculate it using the unit ray:

local unitRay = currentCamera:ViewportPointToRay(VIEWPORT_SIZE.X / 2, VIEWPORT_SIZE.Y / 2)
--raycast 1000 studs in front of the camera
local hitscan = workspace:Raycast(unitRay.Origin, unitRay.Direction*1000)
--default to 1000 studs in front if the ray hits nothing; otherwise use the hit position
local focalPoint = if hitscan then hitscan.Position else unitRay.Origin+unitRay.Direction*1000

Once we have the focal point, we just need to adjust the actual bullet direction to aim at that point. We can use CFrame.lookAt and then retrieve its LookVector:

--the origin would be the gun muzzle
local direction = CFrame.lookAt(ORIGIN, focalPoint).LookVector
module.abilityEvent:FireServer("PrimaryFire", {direction, ORIGIN})

[xDeltaXen]

Here is the code for the client side sending.

A:

I figured it out. I had to send the origin from the client, which by default is the center of the screen. I then had to offset the bullet position by half of the bullet size.

[BetterCallBrenda (Nancy)]

This is seriously awesome!! Thank you so much for your help! I was racking my brain trying to figure it out cuz I suck at math, I really appreciate this not only for the answer but also the explanation. Thank you again!