How can I make a "sphere" out of rays?

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1

I want to be able to use raycasting to create a large radius for detecting parts, but I want it to form a sphere instead of a single direction. I found this function on stack exchange:

for i, obj in pairs(objects) do
      local d = radius + obj.size
      local dx = obj.x - centre.x
      local dy = obj.y - centre.y
      local dz = obj.z - centre.z
      local sqrdist = dx * dx + dy * dy + dz * dz
      if sqrdist <= d * d then
         table.insert(hits, obj)
      end
   end
   return hits
end

the post didn’t provide a lot of information about implementing it. if this function does create a ball of rays could someone show me how I can use it properly?

1 Like
2

Why do you want to create a sphere?

I believe using rays to make something like that may be straining to the server, and without actually knowing why you’d like to use it, I can’t really help.

3

I want to create a turret with some way of detecting things from a distance.

I cant use region3 because region3 cant be moved or deleted as far as I know.

I dont want to use a physical part to represent range because the turret needs to remain a single part and cant be part of a model.

I also read that casting rays isn’t very demanding performance-wise as you can cast hundreds of rays without destroying performance. that is why I would like to use raycasting to accomplish my goal.

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4

You can use the .magnitude property of vectors and scan a list of trackable instances.

5

that doesn’t sound very efficient, I would have to put all if not some parts in a list for the turret to track.

6

You can compare the distance between the turret and all the targets first then cast a ray afterwards.
Trust me, comparing the distance between 2 vectors is really not expensive, even 50 targets a second.

7

sounds like a good method to accomplish what I need, but could you show me an example of getting two vectors and printing the distance?

8

Using rays to create a sphere is redundant. Just use magnitude to find the distance between the target and turret. If the turret isn’t controlled by a player the use of rays is pointless.

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9

You could use Region3 instead of a bunch of raycasts and just use rays for each target in the Region3.

10 
local Range = 50

local Targets = {}
local Players = game.Players:GetPlayers()
for i = 1, #Players do
    local Character = Players[i].Character
    if Character then
        table.insert(Targets, Character.HumanoidRootPart)
    end
end
-- This is not a reliable method to efficiently get all the targets, you need to add PlayerAdded, CharacterAdded and Humanoid.Died events to add and remove targets from the table

while Turret do
    local Closest
    for i = 1, #Targets do
        local Target = Targets[i]
        if not Closest then
            if (Target.Position - Turret.Position).Magnitude <= Range then
                Closest = Target
            end
        else
            if (Target.Position - Closest.Position).Magnitude < (Closest.Position - Turret.Position).Magnitude then
                Closest = Target
            end
        end
    end
    FireTurretAt(Target)
   wait(Cooldown)
end

This is for the magnitude check, you can handle the list of targets you want and put them in a table then iterate through all of them.

11

this would be perfect for detecting characters, but I also want to get specific parts that are also spawned later in the game by the player, would it be ok to get the children of the whole workspace and filter it from there?

12

You can tag and retrieve said parts using the CollectionService. This way you don’t have to filter through all of the workspace.

13

There have been many alternative ways of doing what OP wants, but in case anyone is curious about the original question, here’s the entrance to a whole rabbit hole.