Make ball not appear inside part with raycasting

[kweldev (kwel)]

I’m making a pool table and I want the preview ball appear against the other ball and not inside
robloxapp-20241006-2130097.wmv (575.4 KB)

local function createLine(ball)
	local rayParams = RaycastParams.new()
	rayParams.FilterDescendantsInstances = {ball, aimPart}
	rayParams.FilterType = Enum.RaycastFilterType.Exclude
	local mouse = mouseRaycast()
	local startPos = ball.CFrame.Position
	local targetPos = mouse.Position
	local lookAt = targetPos
	local distance = (startPos - lookAt).magnitude
	local direction = (lookAt-startPos) * distance
	local result = workspace:Raycast(startPos, direction, rayParams)
	if result then
		return result
	end
end

RS.RenderStepped:Connect(function()
	local result = createLine(whiteBall)
	aimPart.Position = result.Position
end)

[hotpocket285]

if you have the position of where the ball will hit against another ball w/ a raycast, you can get the direction of it in accordance to the other ball with vector math

local ballDir = (result.Position - result.Instance.Position).Unit

once you have the direction you just have to offset it by the radius of the ball so its against it

aimPart.Position = result.Instance.Position + ballDir * (result.Instance.Size.X / 2)

[kweldev (kwel)]

Thank you, It works! Now I added a beam from the aimball and to the ball that the raycasting is selecting, how would i make the beam appear after the ball to show the path?

local ballDir = (result.Position - result.Instance.Position).Unit
aimPart.Position = result.Instance.Position + ballDir * (result.Instance.Size.X / 1.005)
local attachment = Instance.new('Attachment', result.Instance)
aimpartBeam.Attachment1 = attachment

[hotpocket285]

you’d have to do the inverse of the ballDir you have already

the vector function is basically

(endGoal - startGoal).Unit -- returns a velocity aiming from the startGoal to the endGoal

so you’d want to get the direction of the bank which would be

local ballBounce = (result.Instance.Position - result.Position).Unit

and you’d make the attachment go from the ball’s current position and the end point of the beam would be something like

local beamLength = 1 -- number i just picked, you can alter this to whatever you wish the length of the beam to be)
local ballBounce = (result.Instance.Position - result.Position).Unit
attachment.WorldPosition = result.Instance.Position + ballBounce * beamLength

[kweldev (kwel)]

U are a genius bro, thank you so much!

[kweldev (kwel)]

Would you also know how i can make ball follow the guide line everytime? Cause it’s really inconsistent.

[hotpocket285]

you’d have to program your own velocity system which wouldn’t necessarily be too hard since its basically spherical collisions on a 2d plane, you already have the direction bc of the ball bounce variable, you’d just have to interpolate the ball to move by a set amount of speed. however if you wish to use roblox physics, it may be inconsistent because the engine isn’t the best at handling sphere movement