Adding an instance's parent to RaycastParams.FilterDescendantsInstances

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#1

I’m making a weapon system that uses raycasts to find multiple player characters, but it isn’t working as there’s a crash bug in it:

module.findHits = function(chr, length)
	if chr.className == "Model" then
		local humanoid = chr:FindFirstChild("Humanoid")
		if humanoid then
			local primary = humanoid.RootPart
			rcParams.FilterDescendantsInstances = {chr}
			rcParams.FilterType = Enum.RaycastFilterType.Blacklist
			local result
			local results = {}
			while true do
				result = game.Workspace:Raycast(primary.position, primary.CFrame.LookVector*length, rcParams)
				if result and result.Instance and result.Instance.Parent.ClassName == "Model" then
					table.insert(results, result)
					table.insert(rcParams.FilterDescendantsInstances, result.Instance.Parent)
					print(rcParams.FilterDescendantsInstances)
				else
					break
				end
			end
			return results
		else
			error("Not a valid object")
		end
	else
		error("Tried to detect for weapon hit from non-model object")
	end
end

The thing is that it’s not adding anything to the rcParams.FilterDescendantsInstances object, making the game crash due to it not breaking the loop. Why doesn’t it add the instance’s parent to the list?

#2

I still need help on this; I can’t seem to fix it. How do you add a object to an array? table.insert doesn’t work.

#3

In your loop, you didn’t add a wait() thus crashing your game/client;
while loops tend to crash if there isn’t a wait() inside them.

while true do
	result = game.Workspace:Raycast(primary.position, primary.CFrame.LookVector*length, rcParams)
	if result and result.Instance and result.Instance.Parent.ClassName == "Model" then
		table.insert(results, result)
		table.insert(rcParams.FilterDescendantsInstances, result.Instance.Parent)
		print(rcParams.FilterDescendantsInstances)
	else
		break
	end
	task.wait(1/60) -- Add a wait here, so the loop doesn't cause a crash
end
#4

The problem isn’t recursion. It’s that the raycast doesn’t add the hit part to result; if all the parts
parents are blacklisted, the raycast won’t hit anything; therefore making result and result.Instance == null, triggering the break. My problem is that it won’t add to rcParams.filterDescendantsInstances, making it recur forever.

#5

This is a very frustrating issue I’ve experienced with using these new modifier objects.

You have to manually construct a new table, add all of your instances in that, and then assign that table as the new value of the FilterDescendantsInstances field.

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FilterDescendantsInstances clones itself every time it's used
#6

Just as a little help, how can I move one table to another? Is there a function; perhaps a cloning function?

edit: nvm- shallowCopy(obj) will do.

#7

You could try:

local function cloneFilterInstancesTable(rcParams)
local newTable = {}

for _, instance in ipairs(rcParams.FilterDescendantsInstances) do
table.insert(newTable, instance)
end

return newTable
end

I’ve actually never tried this though, so I’m not sure if the results would be as expected when trying to read the FilterDescendantsInstances table.

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#8

Seems like a valid usecase for table.unpack or the global function unpack(), check the following for example.

local raycastParams = RaycastParams.new()
raycastParams.FilterDescendantsInstances = {workspace}
raycastParams.FilterDescendantsInstances = {table.unpack(raycastParams.FilterDescendantsInstances), workspace.Terrain}
print(table.unpack(raycastParams.FilterDescendantsInstances)) --Workspace Terrain

To put it simply, you construct a new table value, unpack the currently filtered instances from its table into the constructed one and add additional instances to the constructed table.

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