SLC method of force

Discussion in 'Halo 2 Modding Tutorials' started by TroyMac1ure, Dec 20, 2008 with 3 replies and 1,161 views.

  1. TroyMac1ure

    TroyMac1ure Enthusiast

    Setting the force value doesn't work on system link, this does.
    I did not create this, just found it elsewhere. All credit goes to CaptainPoopface.

    There are a couple of effects in H2 that are used to accelerate objects, such as when you break open the air canisters on Headlong, or when you fire the Scorpion turret. By using markers and a bit of trickery, you can do any of the following things:

    - Thrust yourself forward (grappling hook)
    - Yank an object or enemy toward you, Scorpion-style ("GET OVER HERE!")
    - Shoot someone straight up, or backward, or down
    - Make your biped temporarily run faster
    - Create a weapon that gives you an extra high jump, but with limited ammo
    - Give boost to any vehicle (the warthog is incapable of proper vehi boost)
    - Make a grav gun...

    Go to the effect [EFFE] for the scorpion's cannon_fire. It's the first scorpion effect in the list. Change the marker from cannon_flash to whatever direction you want the acceleration to go. The Havok engine has a few markers that are always available to you, and these are the ones we'll use: forward, backward, up, and gravity (down). For this tutorial, I've changed the marker to forward. Click the marker name, scroll to empty white space, type the new marker name, click the dropdown box again, and select the marker you just typed. Then click Save.

    I've also changed the effect duration to 0.05, because it's a little easier to work with. This will determine how long the acceleration lasts. You will be adjusting it later.


    Now scroll down to the Accelerations reflexive. The acceleration value is the key. I'd recommend setting it at 1 for starters (2 is a strong force, for moving the entire scorpion). Leave the inner and outer cone angles at 0.


    Null all the dependencies of the cannon_fire effect so that you do not have the obnoxious smoke and flashing and noise when you move an object.

    Now pick a projectile [PROJ] that you want to use to apply the acceleration. I've chosen the plasma pistol bolt. In the list of reflexives, you will see a slot for Impact Effect. This effect occurs whenever the projectile hits something. It is almost never used, but hoooooo boy are we going to use it. Swap this to the scorpion's cannon_fire effect. Now, when you shoot something with a plasma pistol bolt, it will accelerate forward!


    Adjust the effect duration and the acceleration value to get the desired outcome. It takes a lot of trial and error. Do you want a sudden, very strong force, or a slightly weaker force that lasts a long time? You decide. This is another one of those times when you will desperately wish for RTH.

    Some important notes about using effect acceleration:
    - Accelerations do not add! If you shoot an object twice with a 0.5 acceleration, it's acceleration is....0.5. This means there is a threshold force you must exceed before an object will move at all.
    - The object must have a phmo, or it won't be moved.
    - The force acts precisely along a vector, at the point of impact. This is quite different from jpt forces, which radiate spherically outward from the point of impact. Why is this important? When you try to move most objects, they will spin wildly. It is as though you are pushing with an invisible finger at exactly the point where you shoot the object, so if it's not the exact center of the object, there will be a net moment about the center of gravity (i.e., it's going to spin).

    It would be nice to work around this. You could try giving an object very high XYZ moments of inertia in the phmo tag, or shoot a big net of projectiles like the shotgun to minimize spinning.

    - Bipeds have something in their phmo (or elsewhere) that does not allow them to spin when they are acted on by forces, so it's much easier to move bipeds than blocs. However, they have high friction forces when in contact with the ground. This means it's much easier to move someone in midair than while he is on the ground. If you want to move bipeds, I recommend using a projectile that explodes on impact, such as the banshee bomb. Make the impact effect accelerate up, and make the detonation effect accelerate forward/backward (duplicate the scorpion cannon_fire effect and change the marker). That way, the biped will be lifted off the ground first, then moved in the direction you want. Alternately, you can clone the Accelerations chunk in the effect and give it another marker.

    - In the [JPT!] for the projectile you are using, be sure to set the force (or instantaneous acceleration) to 0 so that it does not interfere with the effect acceleration.

    - This method is SLC between any player and the host, but off-host to off-host is not yet tested.
    • Like Like x 2
  2. Greeenymeany

    Greeenymeany Enthusiast

  3. semperfi2026

    semperfi2026 Enthusiast

    i Wanna make Grappling Hookzor now.
  4. Blobbo

    Blobbo Newbie

    What the heck was the program used to make this? (PS. Sorry for the bump.)

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