import sys, mujoco, numpy as np
from PIL import Image
m = mujoco.MjModel.from_xml_path(sys.argv[1]); d = mujoco.MjData(m)
for _ in range(int(sys.argv[3]) if len(sys.argv)>3 else 0): mujoco.mj_step(m, d)
mujoco.mj_forward(m, d)
cam = mujoco.MjvCamera(); mujoco.mjv_defaultFreeCamera(m, cam)
with mujoco.Renderer(m, 800, 900) as r:
    r.update_scene(d, cam); Image.fromarray(r.render()).save(sys.argv[2])
print("wrote", sys.argv[2])