Terrain:IsInWater(Vector3 position)

Feature Requests Engine Features
#1

This is needed because using WorldToCellPreferEmpty or WorldToCellPreferSolid is not accurate enough to tell if your head is underwater or not.
If you stand on a shoreline it might say you’re underwater, if you swim in the sea it might say you’re above water.

This issue really makes it difficult to tell if a player is underwater or not.

P.S using Humanoid.Swimming is not accurate enough.

6 Likes
#2

Is ReadVoxels not sufficient? You can specify how small the resolution is.

#3

Here’s a use case for when the admins eventually ask: Drowning mechanic.

#4

GetWaterCell can still be used for this case.

#5

1009×81 4.36 KB

???

#6

The legacy terrain API still has backwards compatibility with smooth terrain, though I’m not sure how long this will be supported.

#7

Its just as inaccurate as the other two stated methods except here you also need to convert your position to terrain coordinates.

#8

How precise are you trying to get it?

#9

± 0.1 studs would be good enough.
Converting to terrain coordinates is ± 2 studs

#10

Including the water waves?

#11

No thats not needed.

#12

I don’t really understand how Humanoid.Swimming isn’t precise enough for you, but I guess you could try this…

local function terrainCast(origin,direction)
	local ignoreList = {}
	for _,v in pairs(workspace:GetChildren()) do
		if v ~= workspace.Terrain then
			table.insert(ignoreList,v)
		end
	end
	local r = Ray.new(origin,direction)
	return workspace:FindPartOnRayWithIgnoreList(r,ignoreList)
end

local function isUnderWater(humanoid)
	local char = humanoid.Parent
	if char then
		local head = char:FindFirstChild("Head")
		if head then
			local hit,pos,norm,mat = terrainCast(head.Position + Vector3.new(0,1000,0),Vector3.new(0,-1000,0))
			if hit and mat == Enum.Material.Water then
				return true
			end
		end
	end
	return false
end
#13

This would suffocate me if I were in an underground cave that has water above it.

P.S. I do have underground caves with water above it.

#14

Alright, maybe try this?

local function terrainCast(origin,direction)
	local ignoreList = {}
	for _,v in pairs(workspace:GetChildren()) do
		if v ~= workspace.Terrain then
			table.insert(ignoreList,v)
		end
	end
	local r = Ray.new(origin,direction)
	return workspace:FindPartOnRayWithIgnoreList(r,ignoreList)
end

local function isUnderWater(humanoid)
	local char = humanoid.Parent
	if char then
		local head = char:FindFirstChild("Head")
		if head then
			local _,ceilingPos = terrainCast(head.Position,Vector3.new(0,1000,0))
			local hit,pos,norm,mat = terrainCast(ceilingPos,Vector3.new(0,-1000,0))
			if hit and mat == Enum.Material.Water then
				return true
			end
		end
	end
	return false
end
1 Like
#15

It would work, if u change -1000 to the distance from head to ceilingpos.
But it would be VERY laggy, given you have to ask this atleast 2 times per second.

The method I use now works, but it’s not very good. But its more efficient than this.
I still think IsInWater is a crucial function that many more than just me uses.

#16

I beg to differ tbh.
I’m not sure why you need it to be this precise, are you sure you aren’t doing something incorrectly?

#17

A person whos head is above water doesnt drown.
Using the current terrain functions he will.

I need to check this often because you get hurt once per second ur underwater once u run out of air.
If you jump once on the water surface then this check might miss it unless it goes atleast twice per second.

#18

cc @Quenty, since he did this with Whatever Floats your Boat.

2 Likes
#19

For me it’s just a Y axis check to determine underwater state as all my water is flat.

This seems like a solid feature request, as we run into this issue with checking if parts are on fire or not too.

Right now the standard way to dynamically do this is a raycast to grab material and/or a cell check, although this is pretty expensive and not too accurate in many cases.

4 Likes