I guess you could try setting its movetype to
MOVETYPE_BOUNCEMISSILE, and possibly its velocity's Z axis' value to 0.
Code:
entity_set_int(ent, EV_INT_movetype, MOVETYPE_BOUNCEMISSILE);
new Float:velocity[3];
entity_get_vector(ent, EV_VEC_velocity, velocity);
velocity[2] = 0.0;
entity_set_vector(ent, EV_VEC_velocity, velocity);
Though not sure if by
above ground you mean
in air or
on ground. If you want for it to stay on ground, then setting its gravity to some high value should do the trick.
Code:
entity_set_float(ent, EV_FL_gravity, 9999.9);