Robot Simulator Software

Hai,

I was wondering if there exists an integrated robot
simulator..........i
mean a simulator where i can somehow input the geometry of the links or
the
design of a mobile robot.......specifications of the
motor...........specifications of the various sensors.........so that,
once
a control algorithm has been given it simulates the performance of the
robot...........i know its possible to simuate dynamics, controls, path

planning etc independently...........but i am looking for a software
which
allows me to simulate the entire robot along with the
environment..............


thanks,
RoboGuru