NWScript:

void bounce_player(location loc) {

    ClearAllActions();

    JumpToLocation(loc);

    ActionDoCommand( SetCommandable(TRUE) );

    SetCommandable(FALSE);

}

void main() {

    // obtain the player and his nearest bouncer

    object player = GetEnteringObject();

    object bouncer = GetNearestObjectByTag( "force_bouncer", player );

    // find the location of player and bouncer

    location player_location = GetLocation(player);

    location bouncer_location = GetLocation(bouncer);

    // extract position vectors

    vector player_position = GetPositionFromLocation( player_location );

    vector bouncer_position = GetPositionFromLocation( bouncer_location );

    // extract other location components

    object player_area = GetAreaFromLocation( player_location );

    float player_ori   = GetFacingFromLocation( player_location );

    // calculate vector away from bouncer through player_point

    vector displacement = player_position - bouncer_position;

    // ensure that the magnitude of the vector is greater than 0

    // otherwise use the inverse of the player's orientation as the vector

    if( VectorMagnitude( displacement ) <= 0.0 ) {

        displacement = -1.0 * AngleToVector( player_ori );

    }

    // normalize the displacement vector

    displacement = VectorNormalize( displacement );

    // multiply displacement by force strength

    float bounce_strength = 3.5;

    displacement = displacement * bounce_strength;

    // calculate new player position by adding displacement to current position

    player_position = displacement + player_position;

    player_location = Location( player_area, player_position, player_ori );

    // Play a neat visual effect

    effect bounce_flash = EffectVisualEffect( VFX_IMP_SUNSTRIKE );

    ApplyEffectAtLocation( DURATION_TYPE_INSTANT, bounce_flash, bouncer_location);

    // Jump the player there

    AssignCommand(player, bounce_player(player_location));

    

    // Apply a knockdown effect

    //effect knock_down = EffectKnockdown();

    //ApplyEffectToObject( DURATION_TYPE_TEMPORARY, knock_down, player, 3.0);

    //AssignCommand(player, ApplyEffectToObject( DURATION_TYPE_TEMPORARY, knock_down, player, 3.0));

}

5. Implementation Notes:
v1
If the player is right on top of the bouncer when the script fires they could possibly be the same, therefore I check the magnitude of the displacement vector before I use it. If the magnitude is zero I simply knock them backwards based on their facing.

This plays a visual effect when they are knocked back, feel free to remove or change the effect to suit your purposes.

If you want to use different bounce strength values for different bouncers or change the bounce strength in a script uncomment the line that checks for a local float on the bouncer.

I wanted to knock the player down as part of the effect, but knockdown seems to crash my client. Poly mentioned the same problem in another thread, but until I know what is causing it I'll have to leave knockdown out. The effect is still pretty cool.

v2
Making the force walls entirely impassable was a real challenge. The problem was that if a player clicks on the screen it clears their action queue. If they have not yet jumped to the bounce point the action will be cancled, since they are still inside the trigger it won't fire again and they can walk through. This made it very easy to walk right through the wall by rapidly clicking. My solution was to disable player control using SetCommandable() after filling their queue. Unfortunatly a bug with AssignCommand() prevented this from working and it took several hours to hit on something that worked. There are two issues with AssignCommand(), the first is probably not a bug and is related to timing. The AssignCommand() seems to be delayed until after the current script has executed, this makes sense. What doesn't make sense is that if you set commandable to false after you have assigned a command, the assign function will not work. Instead you must order the player to use setcommandable on himself. The second problem with assign I believe is a bug, although possibly related to timing as well. If you have multiple AssignCommand() calls, they may not all be executed. Sometimes they will be, but it is not reliable. Putting all of the commands into a function and assigning that function with a single assign call seems to be a good work around.

If anyone finds a way to walk through one of these fields (as a player without jumping) please let me know.

-Solias