Ou... and that jump code:
First you must do that the object don´t drop below ground height
gh#=get ground height(1)
if object position y(1)<gh#+20 then position object 1,object position x(1),gh#+20,object position z(1)
then jump using real physics:
timestep#=(timer()-time)/1000 : time=timer()
if spacekey()=1 and object position y(1)=gh#+20
objectmass#=80 rem kilos(Kg)
jumpforce#=1000 rem newtons(N)
acceleration#=jumpforce#/objectmass#
gravity#=9.81
endif
acceleration#=acceleration#-gravity#*timestep#
velocity#=velocity#+acceleration#*timestep#
yadd#=velocity#*timestep#
if object position y(1)+yadd#<gh#+20 then acceleration#=0 : velocity#=0 : yadd#=0
position object 1,object position x(1),object position y(1)+yadd#,object position z(1)
You can chance gravity, objectmass and jumpforce so that jumpping feels right.