I am trying to make a system that can revolve any amount of parts around a character, while keeping the same spacing between parts.
Here is an image of what I am trying to accomplish (notice the motor is always facing the character, I am trying to keep the front of the part always facing the character)
Could you place an Attachment and a HingeConstraint in the player and put Attachments in each Part to that?
Dunno how a HingeConstraint would work with something as mobile as a Player, but they seem pretty stable on vehicles.
You’d probably have to check the Massless property of all the Parts that are rotating so they don’t affect the Player’s movements.
So to start off, you probably need to know what the unit circle is in order to do this. Since you’re really only working in two dimensions (the height of the parts remains constant), we can represent your problem with x and y on a plane like so:
You can go here to play around with it:
An important thing to remember is that the unit circle uses radians, not degrees. Instead of representing a point on this circle with an x and y, it’d be much more intuitive to use a single angle measurement, right?
The full distance around the circle in radians comes out to be 2 * pi, here’s a chart for other measurements around the circle:
Since a full rotation is 2 * pi radians, a half rotation is just pi, or (2 * pi) / 2. Using this way of thinking, one can reason that (2 * pi) / an amount gives you the radian measurement for that length around the circle. Say you wanted 1/8 of the circle, well then (2 * pi) / 8 would give you that.
If we think about doing this in lua the easiest way would be to set up a table of parts that you would want to manipulate. Since this is part of the character, I’ll put the script in StarterCharacterScripts:
local character = script.Parent
local hrp = character:WaitForChild("HumanoidRootPart")
local parts = {}
local numberOfParts = 8
for _ = 1, numberOfParts do
table.insert(parts, Instance.new("Part")) -- put the parts into the table
end
for i, part in pairs(parts) do -- set the properties of the parts
part.Anchored = true
part.CanCollide = false
part.Parent = workspace
end
Then we can set up some variables for the unit circle
local fullCircle = 2 * math.pi
local radius = 10 -- the radius of the parts from the character
Now we need to figure out how we would get the x and y coordinates from the angle, luckily for us mathematicians have worked this out already, the y on a unit circle can be found by sin(angle) and the x can be found by cos(angle):
(t being the angle in radians)
We can write up a function to do this to get the x and y positions for any given angle, but since we’re not changing the y position of the part, only the x and z, we’ll use z instead of y. We can also multiply each number by the radius to set the radius of the circle, like this:
local function getXAndZPositions(angle)
local x = math.cos(angle) * radius
local z = math.sin(angle) * radius
return x, z
end
I think the best way to set the positions is to set the positions every frame, but you might think of a better way. Here’s what I’ve done with a function connected to Heartbeat in RunService.
To get the angle of the part, you can get the section of the circle for the first part and then multiply it by the number of the current part
game:GetService("RunService").Heartbeat:Connect(function()
for i, part in pairs(parts) do
local angle = i * (fullCircle / #parts)
local x, z = getXAndZPositions(angle)
-- multiplying CFrames combines them:
local position = (hrp.CFrame * CFrame.new(x, 0, z)).p -- .p gets the position part of the CFrame as a Vector3
local lookAt = hrp.Position
part.CFrame = CFrame.new(position, lookAt) -- a CFrame constructor that takes a position and a lookAt value and returns a CFrame looking that that position
end
end)
local character = script.Parent
local hrp = character:WaitForChild("HumanoidRootPart")
local parts = {}
local numberOfParts = 8
for _ = 1, numberOfParts do
table.insert(parts, Instance.new("Part"))
end
for i, part in pairs(parts) do
part.Anchored = true
part.CanCollide = false
part.Parent = workspace
end
local fullCircle = 2 * math.pi
local radius = 10
local function getXAndZPositions(angle)
local x = math.cos(angle) * radius
local z = math.sin(angle) * radius
return x, z
end
game:GetService("RunService").Heartbeat:Connect(function()
for i, part in pairs(parts) do
local angle = i * (fullCircle / #parts)
local x, z = getXAndZPositions(angle)
local position = (hrp.CFrame * CFrame.new(x, 0, z)).p
local lookAt = hrp.Position
part.CFrame = CFrame.new(position, lookAt)
end
end)
