diff --git a/doc/overview.rst b/doc/overview.rst index de6f5369..4c8e4638 100644 --- a/doc/overview.rst +++ b/doc/overview.rst @@ -611,13 +611,13 @@ away and cause divergence. .. _Units: -Units are undefined -~~~~~~~~~~~~~~~~~~~ +Units are unspecified +~~~~~~~~~~~~~~~~~~~~~ -In MuJoCo basic physical units are undefined. The user may interpret the system of units as they choose, as long as it -is consistent. To understand this, consider an example: the dynamics of a 1 Meter spaceship that weighs 1 Kg and has a 1 -Newton thruster are the same as those of a 1 cm spaceship that weighs 1 gram and has a 1 dyn thruster. This is because -both `MKS `__ and `CGS +MuJoCo does not specify basic physical units. The user may interpret the system of units as they choose, as long as it +is consistent. To understand this, consider an example: the dynamics of a 1 meter spaceship that weighs 1 kilogram and +has a 1 Newton thruster are the same as those of a 1 cm spaceship that weighs 1 gram and has a 1 dyn thruster. This is +because both `MKS `__ and `CGS `__ are consistent systems of units. This property allows the user to scale their model as they choose, which is useful when simulating very small or very large things, to improve the numerical properties of the simulation. @@ -625,7 +625,7 @@ very large things, to improve the numerical properties of the simulation. That said, users are encouraged to use MKS, as there are two places where MuJoCo uses MKS-like default values: - The default value of :ref:`gravity