Raycast Not Detecting Water (Or Anything) Under Boat

[MrGustavio (GUSTAV)]

1. What do you want to achieve?
   I’ve been trying to make a raft/boat that goes at full speed only when it’s in water, and slows down significantly when it’s not

2. What is the issue?
   When printing the raycast result, it always prints nil, no matter what solution I’ve tried. The raycast always finds nothing, no matter what’s below it.
   

   
   
   

3. What solutions have you tried so far?
   I looked through many solutions of the DevForum, but the ones that make sense don’t seem to work. I tried increasing the direction length from -1 to -100, I tried bringing the raycast origin height to a higher position, etc.

Example of something I tried:

Raycasting to detect terrain?

I tested the place. First things first, the code is in a local script so it doesn’t run. You need to place it in a server script if you want it to run server-side. Also I’ve found out the issue. The problem is that the position of the raft is already in the water, so it ignores the water and the next thing the ray picks up is the grass underneath. Rays have this weird thing where if the starting position is within a part, it ignores that part. To fix this is simple, set the starting position of…

4. My code:

local rayParams = RaycastParams.new(workspace.Terrain)
rayParams.FilterType = Enum.RaycastFilterType.Include
rayParams.IgnoreWater = false

local function waterMult()
	local result = workspace:Raycast(Vector3.new(primary.Position)+Vector3.new(0,10,0), Vector3.new(0,-1,0)*100, rayParams)
	print(result) -- always printing nil
	if result then
		if result.Material == Enum.Material.Water then
			return 1 -- full speed
		else
			return .1 -- diminished speed
		end
	end
	return .1 -- no result found (diminished speed)
end

[Katrist]

What is primary? RaycastParams.new doesn’t recieve a parameter, so I’m not sure what you were trying to do. You also shouldn’t using Enum.RaycastFilterType.Include.

Code (assuming that primary is just a part in the boat, and that primary.Parent is the boat’s model):

local rayParams = RaycastParams.new()
rayParams.FilterType = Enum.RaycastFilterType.Exclude

local function waterMult()
	rayParams.FilterDescendantsInstances = {primary.Parent}

	local result = workspace:Raycast(primary.Position + Vector3.new(0, 10, 0), Vector3.new(0, -100, 0), rayParams)
	
	if result and result.Material == Enum.Material.Water then
		return 1 -- full speed
	end
	
	return .1 -- no result found (diminished speed)
end

Also, .IgnoreWater is by default set to false.

[MrGustavio (GUSTAV)]

My bad, I found a solution to my problem that doesn’t require raycasting at all. It works beautifully.
Thank you Katrist for helping me, you rewrote my code much more efficiently than I did

Detecting If User Is In Water

I actually did something like this today, but the system was to either detect if someone was jumping on top of the water or was inside the water, it was quite easy (after finding out that using rays wouldn’t be that good compared to using regions). The whole idea is to use Region3 and workspace.Terrain:ReadVoxels with the Head’s position (well region). If the player is on top of water or inside water in general then their floor material will be Air, so a way to filter out the players that are …

The code:

local function waterMult()
	local primePos = primary.Position

	local min = primePos - primary.Size
	local max = primePos + primary.Size
	local region = Region3.new(min,max):ExpandToGrid(4)

	local material = workspace.Terrain:ReadVoxels(region,4)[1][1][1]
	if material == Enum.Material.Water then
		return 1 -- full speed
	end

	return .1 -- water not found (diminished speed)
end