Pointing a players arm towards a part

Help and Feedback Scripting Support
, ,
#1

Hello reader, hope you’re having a great day.

How would I go about pointing a players arm towards a part? More specifically, I am unsure how to go about manipulating the players’ shoulders’ Motor6D.C0 property to point towards a part each RenderStepped while using the shoulders natural position.

I have this code so far, which works, but the shoulder remains at the midpoint of the arm (Part0):

local shoulder: Motor6D = character["LeftUpperArm"]["LeftShoulder"];
local jointPosition = shoulder.Part0.CFrame:toWorldSpace(CFrame.new(0,0,0))
local cframe = CFrame.new(jointPosition.p, workspace.PartToPointAt.Position) * CFrame.Angles(math.pi/2, 0, 0) * CFrame.new(0, -1, 0)
shoulder.C0 = shoulder.Part0.CFrame:toObjectSpace(cframe)

I cannot use pre-defined offsets, as the R15 rigs scale during gameplay.

Thanks a lot for your help.
~ P3tray

5 Likes
Help with getting arm to point to vector3
#2

You could use the look at function to do that.

1 Like
#3

Could you elaborate? I’ve been messing with this for about 6 hours. This is a cry for help.

2 Likes
#4

Can you tell me the part name which is the highest in the hand? Like the shoulder name

1 Like
#5

The shoulder is called shoulder. This is an R15 rig. All default Roblox R15 rigs are named the same.

#6

No not the rig name, the part name. Let me see actually

1 Like
#7

It’s game.Workspace.PartToPointAt as seen on Line 3 in the question.
image

#8 
local lookAtCFrame = CFrame.lookAt(Shoulder.Position,LookAtPart.Position) -- This will the CFrame you should set your shoulder to
1 Like
#9

Try this code right here and change the names, tell me if it works

1 Like
#10

What am I supposed to do with lookAtCFrame? Where does this go in my code?

#11

lookAtCFrame is a CFrame value which you need to set as your shoulder CFrame

1 Like
#12

This creates a CFrame that is angled to face the LookAtPart.
But, it aligns it with the front. If improper alignment occurs, you can use a CFrame.Angles():

lookAtCFrame = lookAtCFrame * CFrame.Angles(0, math.rad(90), 0)
--using math.rad(90) for an example
2 Likes
#13

Mark my code as solved if it worked for you by the way :smile:

1 Like
#14

So my final code would look like this, if it so happens to point in the right direction?

local shoulder: Motor6D = character["LeftUpperArm"]["LeftShoulder"];
local jointPosition = shoulder.Part0.CFrame:toWorldSpace(CFrame.new(0,0,0))
local cframe = CFrame.lookAt(Shoulder.Position,LookAtPart.Position)
shoulder.C0 = shoulder.Part0.CFrame:toObjectSpace(cframe)
1 Like
#15 
local RunService = game:GetService("RunService")
local TargetPart = game.Workspace.Part

RunService.RenderStepped:Connect(function()
Character.IDontKnow.Motor6D.C0.CFrame = CFrame.new(Character.IDontKnow.Motor6D.C0.CFrame.Position, TargetPart.Position)
end)

Hope this helps.

1 Like
#16

Probably. I’m still new to a lot of things in Lua, so I don’t know what shoulder: Motor6D does.

Edit: I think it’s based on finding an instance with like values assigned.

1 Like
#17

It’s typescript. It defines the local variable shoulder as a Motor6D. It will error if it is not a Motor6D.

It is useful as by default Roblox doesn’t always know what type of thing a variable is, which means it cannot assist you with tab completion.

#18

Makes sense. I’m more of a Javascript person personally, so a good amount of this is still new.

1 Like
#19

This does not work. The arm has moved to a fixed position, and is not pointing at the part. Player movement does not effect the arm. The result is exactly the same if I replace CFrame.new with CFrame.lookAt.

Thank you for your contribution.

2 Likes
#20

Truly a 1,000 IQ thread. Never before seen such intelligent answers.

2 Likes