How Do A Ray Ignore Transparent Parts?

You would just go through the descendants and add the transparent parts to the ignore list.

local ignore = {}

for i,v in pairs(workspace:GetDescendants())do
	if v and v:IsA("BasePart") and v.Transparency >= 1 then -- 1 means fully transparent, so set this to the minimum transparency you want the ray to ignore
		table.insert(ignore,v)
	end
end

-- Then you would do

workspace:FindPartOnRayWithIgnoreList(ray,ignore) -- provided you have defined "ray"