TEST E2

@name Simple PN Guidance
@inputs N:number TargetPos:vector
@persist LastR:vector LastTime:time LastPos:vector LastVel:vector
@outputs OutForce:vector

interval(1)
# 1) Time & positions
local t  = clk()
local dt = t - (LastTime?:t)
if (dt <= 0) { LastTime = t return }
LastTime = t

local Pos = entity():pos()
local R   = TargetPos - Pos
local Range = R:length()
if (Range <= 0) { return }

# 2) LOS unit & relative velocity
local u    = R / Range
local Vel  = (Pos - (LastPos?:Pos)) / dt
local Vrel = Vel - (LastVel?:vec(0,0,0))
LastPos = Pos
LastVel = Vel

# 3) Closing speed
local Vc = -Vrel:dot(u)

# 4) LOS rate
# ū̇ = (Vrel − u*(Vrel·u)) / R
local uDot = (Vrel - u*(Vrel:dot(u))) / Range

# 5) Commanded accel
local aCmd = uDot * (N * Vc)

# 6) Turn into force for a vector thruster: F = m·a
# assume you set mass elsewhere, e.g. Mass input or convar
local mass = entity():getMass()  # or pass in as @input
OutForce @= aCmd * mass