scripts/Bullet.LACE

   1 # Bullet shot vertically up
   2 #
   3 # z'' = -g -af = -g -k*v^2
   4 #     with k = 1/m * 1/2 * A * c.w * rho
   5
   6 coefficient.1(-1) -> -g    # gravity
   7 coefficient.2 -> k         # coefficient of friction
   8 coefficient.3(+1) -> v0    # initial vertical speed
   9
  10 iintegrate (-g, 10*: friction) -> -v
  11   IC: v0
  12 iintegrate (-v) -> z
  13
  14 invert -v -> v
  15
  16 multiply (-v, -v) -> v^2
  17 cmultiply (k, v^2) -> kv^2
  18
  19 # make sure friction acts against the direction of propagation
  20 invert kv^2 -> -kv^2
  21 compare v -> friction
  22   GT0: -kv^2   # v > 0 => moving upwards
  23   LT0:  kv^2   # v < 0 => moving downwards
  24
  25 output (v)        -> out.x
  26 Output (friction) -> out.y
  27 output (z)        -> out.z