approximate measurements of rope in the Source engine are available here
this will look at non-solid ropes that aren't affected by wind
a JS implementation is available
Ropes in the Source engine span from a move_rope
to a keyframe_rope
(or from a keyframe_rope
to a keyframe_rope
).
In both cases two values are relevant for the rope simulation: slack and subdivision.
Slack indicates how low the rope hangs. It is simply a scalar value (usually in the range of a few hundred) that is added to the length of the rope when it is initialized [1].