Set part's CFrame based off of 2 attachments

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#1

Ok, this is a bit of a tricky question to explain, but I will try my best to explain it.

I’m trying to make a building system where these 2 attachments line up and snap together if in close enough proximity

c5f67d85573598e707d4c21b8e9b7b6b
c5f67d85573598e707d4c21b8e9b7b6b1546×529 438 KB 

local Debounce = false

local Orientation = BuildPreview.PrimaryPart.CFrame - BuildPreview.PrimaryPart.Position
		
BuildPreview:SetPrimaryPartCFrame(Orientation + Mouse.Hit.Position)
		
for _,CurrentAttachment in pairs(BuildPreview.BoundingBox:GetChildren()) do
	for _,OtherAttachment in pairs(game:GetService("CollectionService"):GetTagged("BuildAttachment")) do
		if CurrentAttachment.Parent ~= OtherAttachment.Parent and OtherAttachment:IsDescendantOf(game.Workspace) then
			if (CurrentAttachment.WorldPosition - OtherAttachment.WorldPosition).Magnitude < 1 and Debounce == false then
						
				Debounce = true
						
				BuildPreview:SetPrimaryPartCFrame(CFrame.new(OtherAttachment.WorldPosition))
			end
		end
	end
end

This script does this:

But I want the two attachments to line up. Instead what I have right now is just setting the builds position to the other attachments position

#2

try looking at weld maths for attachment snapping

part1.CFrame * C1 == Part0.CFrame * C0
--C1 and C0 are CFrame offsets, the same as attachments CFrame as attachments CFrame is relative to the parent
part1.CFrame * part1.Attachment.CFrame = Part0.CFrame * part0.Attachment.CFrame 
--Solve for part1 which is the one thats being dragged
part1.CFrame = Part0.CFrame * part0.Attachment.CFrame*part1.Attachment.CFrame:Inverse()
--Up to you to find the two attachments closest to each other
#3

AllignPosition and others of the sort will not work because the parts need to be anchored, and with the equasion that you provided to me, I can’t use CFrames for reasons. Is there any way I could calculate it with just Vector3’s?

#4

Why not use CFrames? I see the code up there already uses CFrames.

I believe It can be adjust it like this:

local part1FormulaCF = OtherAttachment.Parent.CFrame*OtherAttachment.CFrame*CurrentAttachment.CFrame:Inverse()
BuildPreview:SetPrimaryPartCFrame(part1FormulaCF)
1 Like
#6

This does not work. It just sets the BuildPreview’s CFrame to the parts CFrame

#7 
local wallCframe = RaycastInstance.CFrame *CFrame.new(attachment.Position)
wallCframe = wallCframe *CFrame.new(-ClonedSample.Attachment.Position)
wallCframe = wallCframe *CFrame.Angles(0, math.rad(attachment.Orientation.Y), 0)
ClonedSample.CFrame = wallCframe