Any way to bypass this raycasting issue?

[C_Sharper (Sharpie)]

Hey, so I’m having an issue with some raycasting code.

Basically, if the origin (start position) of the ray is colliding with another part that I want the ray to hit, it won’t hit it, despite it being directly in the ray’s path.

This is a problem I’ve always been aware of with raycasting, and it just came up again as I was playtesting. I wondered if there was a bypass I could do with collision groups, although that might make it so the rays can’t hit those parts entirely.

I hope this post makes sense, if not I can try to clarify further.

Thank you!

[JackscarIitt (Jackscarlett)]

I don’t believe there is a reference that allows a ray to pierce through parts, but you could use a loop perhaps?

Ray detecting multiple parts at once

There’s no built-in way of doing this. But you can achieve the same effect by raycasting repeatedly, adding each target to an ignore list before doing the next raycast. One implementation might look like so: function findAllPartsOnRay(ray) local targets = {} repeat local target = game.Workspace:FindPartOnRayWithIgnoreList(ray, targets) if target then table.insert(targets, target) end until not target return targets end You can read up on the other two raycasting functions here and…

I’ve always wondered this issue myself as well, and I suppose a search showed this

[SOTR654]

Use RaycastParams to ignore/detect what you want, and are you using CFrame.LookVector?

Raycasting

[JackscarIitt (Jackscarlett)]

@C_Sharper

although that might make it so the rays can’t hit those parts entirely.

I believe he’s wanting the ray to pierce through all the parts? And not just ignore specific parts?

[SOTR654]

It depends on how you set it, as FilterDescendantsInstances is a table, you can put everything you don’t want inside and put FilterType in BlackList

[RatiusRat (Boopmaster)]

If he wants the ray to not hit anything then you can set a whitelist to nothing.

[Moonvane]

This should do it

(Not tested)

function findPartOnRayWithOriginInsidePart(part, originPos, direction, raycastParams)
    
    local function originIsInsidePart()

        local positionPart = Instance.new("Part")
        positionPart.Size = Vector3.new()
        positionPart.CFrame = CFrame.new(originPos)
        positionPart.CanCollide = true
        positionPart.Transparency = 1
        positionPart.Anchored = true
        positionPart.Parent = workspace

        local touchingParts = getNonCanCollideTouchingParts(positionPart) -- just in case the part is non cancollide
        
        positionPart:Destroy()

        for _, touchingPart in next, touchingParts do
            if touchingPart == part then
                return true
            end
        end

        return false
    end

    if originIsInsidePart() then
        return {
            Instance = part;
            Position = originPos;
            Normal = direction;
        }
    else
        return workspace:Raycast(originPos, direction, raycastParams)
    end
end

[LiegePalpatine (Kriss)]

You could use fastcast comes with a built in function

[JackscarIitt (Jackscarlett)]

Still

Is it possible to get all parts intersecting a Ray?

I have a GJK distance and intersection implementation. That should work until a c++ implementation is made. I ran into issues like this years ago (particularly when working on my navigation mesh pathfinder). Below is pretty much all the code you need. You could remove the spherical check, since the maximum number of parts FindPartsInRegion3 returns is relatively small. I’d recommend replacing FindPartsInRegion3 with my AABB structure if the parts wont be moving around too much. --< BEWARE >--…

FilterDescendantsInstances would only ignore the specific parts when the ray gets cast in a direction, not detect them individually, and I don’t believe it wouldn’t matter if you were to set the FilterType to a Whitelist or a Blacklist since the Ray would detect the first part that it hit then stop regardless

[SOTR654]

Nothing that a loop doesn’t solve, right?

while wait() do	
	local rayresult = workspace:Raycast(origin,direction,Params)
	if not rayresult then		continue/return		end
	print(rayresult.Instance)
end

And the problem of @C_Sharper is the distance of the ray, surely he is using CFrame.LookVector as direction.

[RatiusRat (Boopmaster)]

Maybe you could use game:GetServer(“Runservice”).Heartbeat:Wait() instead of Wait().

[P1xelR3n (Pix3lR3n)]

You could detect when the Raycast hit’s a desired object, and then continue the Raycast by sending another Raycast from the point it hit in the same direction it’s heading towards.