This seems like simple code, but roblox isn’t finding anything in the region. Here’s my code:
function PartToRegion3(part)
local PointA, PointB = part.CFrame * (0.5 * part.Size) , part.CFrame * (-0.5 * part.Size)
local rg = Region3.new(PointA, PointB)
return rg
end
local rg = PartToRegion3(game.Workspace.RacePoints.Finish1)
while true do
for i,v in pairs(game.Workspace:FindPartsInRegion3(rg, nil, math.huge)) do
print(v.Name)
end
wait(3)
end
Remember: A region’s boundaries / faces will always be parallel to world axes. The region’s corners will be located at your part’s corners, but it will be rotated if there’s any rotation on the part which is not a multiple of 90 degree. If your part is rotated, you should be using BasePart:GetTouchingParts instead. Make sure to create a .Touched event for your main part if its uncollidable before, as it won’t work otherwise. You can just connect it to an empty function.
Taken from my module, you can easily modify it though:
module.Region3FromPart = function(Part) --Not written by me lel.
local Size = Part.Size
return Region3.new(Part.Position-(Size/2),Part.Position+(Size/2))
end
EDIT: didn’t mean to reply to you oof
EDIT 2: I originally got the code from here: Quick Explanation on Region3? - Scripting Helpers 
Solutions that just add the size fail to account for cases where the part is rotated. I think the best solution is to use the part’s bounding box.
function PartToRegion3(part)
local abs = math.abs
local cf = obj.CFrame -- this causes a LuaBridge invocation + heap allocation to create CFrame object - expensive! - but no way around it. we need the cframe
local size = obj.Size -- this causes a LuaBridge invocation + heap allocation to create Vector3 object - expensive! - but no way around it
local sx, sy, sz = size.X, size.Y, size.Z -- this causes 3 Lua->C++ invocations
local x, y, z, R00, R01, R02, R10, R11, R12, R20, R21, R22 = cf:components() -- this causes 1 Lua->C++ invocations and gets all components of cframe in one go, with no allocations
-- https://zeuxcg.org/2010/10/17/aabb-from-obb-with-component-wise-abs/
local wsx = 0.5 * (abs(R00) * sx + abs(R01) * sy + abs(R02) * sz) -- this requires 3 Lua->C++ invocations to call abs, but no hash lookups since we cached abs value above; otherwise this is just a bunch of local ops
local wsy = 0.5 * (abs(R10) * sx + abs(R11) * sy + abs(R12) * sz) -- same
local wsz = 0.5 * (abs(R20) * sx + abs(R21) * sy + abs(R22) * sz) -- same
-- just a bunch of local ops
local minx = x - wsx
local miny = y - wsy
local minz = z - wsz
local maxx = x + wsx
local maxy = y + wsy
local maxz = z + wsz
local minv, maxv = Vector3.new(minx, miny, minz), Vector3.new(maxx, maxy, maxz)
return Region3.new(minv, maxv)
end
(bounding box code adapted from zeuxcg’s code)
Thank you so much for this, that is extremely useful and well thought out. Exactly what I was looking for.