Particle Emitter (RandomPeripherals)

local partMax, delay = 8, 0.1
local block = {"minecraft:wool", "minecraft:stained_glass", "minecraft:stained_glass_pane", "minecraft:stained_hardened_clay"}
local holo = {peripheral.find("hologram_projector")}

do
    local interfaces = {peripheral.find("universalInterface")}
    for i = 1, #interfaces do for _, side in pairs(rs.getSides()) do
        local thisPer = interfaces[i].wrapPeripheral(side)
        if thisPer.setVelocity then holo[#holo + 1] = thisPer end
    end end
end

if #holo == 0 then error("No projectors found.") end

local particles = {}
for i = 1, #holo do
    holo[i].clear("minecraft:air", 0)
    holo[i].setVelocity(1)

    particles[i] = {}
    for j = 1, partMax do particles[i][j] = {3.5, 0, 3.5, math.random() - 0.5, math.random(), math.random() - 0.5, block[math.random(#block)], math.random(16) - 1} end
end

while true do
    for i = 1, #holo do
        local thesePars = particles[i]
        local holoMap, marked = {}, {}
        for j = 1, #thesePars do
            local thisPar = thesePars[j]
            local PosMark = thisPar[1] .. thisPar[2] .. thisPar[3]

            if not marked[PosMark] then
                holoMap[#holoMap + 1] = {["x"] = thisPar[1], ["y"] = thisPar[2], ["z"] = thisPar[3], ["name"] = "minecraft:air"}
                marked[PosMark] = true
            end

            thisPar[1] = thisPar[1] + thisPar[4]
            thisPar[2] = thisPar[2] + thisPar[5]
            thisPar[3] = thisPar[3] + thisPar[6]

            if thisPar[1] < 0 or thisPar[1] >= 8 or thisPar[2] >= 8 or thisPar[3] < 0 or thisPar[3] >= 8 then
                 thisPar = {3.5, 0, 3.5, math.random() - 0.5, math.random(), math.random() - 0.5, block[math.random(#block)], math.random(16) - 1}
                 particles[i][j] = thisPar
            end

            holoMap[#holoMap + 1] = {["x"] = thisPar[1], ["y"] = thisPar[2], ["z"] = thisPar[3], ["name"] = thisPar[7], ["meta"] = thisPar[8]}
            marked[thisPar[1] .. thisPar[2] .. thisPar[3]] = true
        end

        holo[i].draw(holoMap)
    end

    sleep(delay)
end