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How to obtain a list of all items hit by a ray?

Asked by

6 years ago

Is it possible to use a raycast from one point to another, and then making a table of all objects which the ray has passed through, rather than just returning the first object hit?

3 answers

Answered by

ABK2017 406

6 years ago

I dont know if there’s a more effiecient way, but you can repeatedly GetAllParts and then add them to the ignore list until it returns nothing (nil).

01local function GetAllParts(Ray)
02    local Parts = {}
03    local Last
04 
05    repeat
06        Last = workspace:FindPartOnRayWithIgnoreList(Ray, Parts)
07        table.insert(Parts, Last)
08    until Last == nil
09 
10    return Parts
11end

Answered by

ozzyDrive 670

6 years ago

Edited 6 years ago

You can take advantage of theworkspace.FindPartOnRayWithIgnoreList function. Every time a new contact is found, add it to the ignore list, find the next contact point and repeat the process until there are no points found.

https://gyazo.com/b62269248ed0c683cc1aa0aab3b8c33b

Here's the sample code I wrote to generate the above result:

01local function drawRay(ray)
02    local part = Instance.new("Part")
03 
04    part.Name = "ray"
05    part.Anchored = true
06    part.BrickColor = BrickColor.new("Bright yellow")
07 
08    local origin, direction = ray.Origin, ray.Direction
09 
10    part.Size = Vector3.new(0.2, 0.2, direction.Magnitude)
11    part.CFrame = CFrame.new(origin, origin + direction) * CFrame.new(0, 0, -direction.Magnitude/2)
12 
13    part.Parent = workspace
14    return part
15end
16 
17local function drawContactPoint(v3)
18    local part = Instance.new("Part")
19 
20    part.Name = "contact"
21    part.Anchored = true
22    part.BrickColor = BrickColor.Red()
23 
24    part.Size = Vector3.new(0.5, 0.5, 0.5)
25    part.CFrame = CFrame.new(v3)
26 
27    part.Parent = workspace
28    return part
29end
30 
31local function getAllContactPoints(ray)
32    local parts = {}
33    local points = {}
34 
35    repeat
36        local part, point = workspace:FindPartOnRayWithIgnoreList(ray, parts)
37        if part then    --  exclude the ray's end point
38            table.insert(parts, part)
39            table.insert(points, point)
40        end
41    until not part
42 
43    return points, parts
44end
45 
46--
47 
48local laser = workspace.laser
49 
50local ray = Ray.new(laser.Position, laser.CFrame.LookVector * 200)
51drawRay(ray)
52 
53local contactPoints = getAllContactPoints(ray)
54for _, point in next, contactPoints do
55    drawContactPoint(point)
56end
 View all 56 lines...

EDIT: Made sure the getAllContactPoints function doesn't return the ray's end point.

Answered by

gullet 471

6 years ago

There's no native way of getting them all, you'll have to loop FindPartOnRayWithIgnoreList and keep adding each hit part to the ignore list until there are no more hits.

How to obtain a list of all items hit by a ray?

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