FXTutorials

Some may recognize the similarity of this shot to a similar one seen in The Descendants Teaser Trailer.  My attempt is similar, but nowhere near the same.  I don't know, but you might be able to do this in CC Particle World instead of Trapcode's Particular (if you want to avoid spending hundreds of dollars).

Shooting on a tripod is easiest here, but it wouldn't be hellish to motion track a shot like this.  Also, I shot mine in the morning and it's kind of bright.  Slightly darker lighting would be better because there are going to be bright elements in the shot.  In The Descendants Teaser it is night when this effect is shown.

    So, the first thing you're going to want to do is import your footage.
    Make a new solid (any color) that's the same size as the comp. 
    Apply the lightning effect to it (effect > generate > lightning).  Now, there are a lot of settings to mess with.  Here's a screen grab of mine.  Don't bother to hit any of the stopwatches yet, though.
    Set the layer's (not the effect's) blend mode to screen.
    Now, move to the first frame where your lightning is going to be fully "extended" (If you're not sure when that will be, it took 7 or 8 frames in my video).  Then, position the start point on your actor's hand and the end point out of frame if the forcefield isn't in frame yet like in my shot, or touching the forcefield if both actors are in frame together.  Does that make sense?
    When the lightning is positioned the way you want it, set keyframes for the start and end points.  Also, set a keyframe for the amplitude.
    Now, duplicate your lightning layer 3 times so that you now have 4 layers (5 counting the footage).  You can add more if you want, but I thought four looked to be enough.
    Set the "Random Seed" of each of the lightning layers to different individual values.  This, in a way, separates each of the lightning layers from each other, except at the end points.
    What I did next was to put two start points on each hand.  I then went to the end points and separated them from each other vertically.
    You're now going to have to work backward, frame by frame, moving each start point to the hand it belongs to, until you reach the first frame you want the lightning to come out of the hands.  In addition to that, animate the end points to come toward the hands as well.
    Now, at the first frame with lightning, change the "Amplitude" for each lightning layer down to about 2.  This makes it so the lightning doesn't look like it isn't "squished".
    Then, go back to the last frame with keyfames and animate each of the points forward in time as far as you need to go.
    At this point, pre-compose the lightning layers (layer > pre-compose).  You can name this comp "Matte"
    Now, in the main comp apply the "Fast Blur" (effect > blur & sharpen > fast blur) effect to the matte comp you just created and duplicate it 3 times and pre-compose those.  Name this comp "Lightning Final"
    In the "Lightning Final" comp, make a new black solid that's the comp size and put it below the "Matte" layers.  Open each "Matte" layer's "Fast Blur" settings and check the "Repeat Edge Pixels" option for each.
    Set the top layer's blur to 1, the next to 10, the next to 20, and the last to 40.
    In the main comp, set the "Lightning Final" comp's blend mode to screen and apply the "Color Balance effect to it (effect > color correction > color balance).
    In the "Color Balance" effect, check the "Preserve Luminosity" option and adjust the midtones and highlights until you achieve the color you're looking for.

    What I did now was add light around my hands.
    I grabbed Ryan Wieber's Lightsaber Contact Flash, froze it on the first frame, scaled it down, duplicated it (one for each hand), set the blend mode to add, then matched the movement of my hands.  Then, I keyframed the opacity so the lights would fade in as the lightning was about to appear.
    Another thing I did was duplicate the contact flashes, turn down the opacity, and increase the vertical scale to make them look like vertical lens flares.

    Alright, on to the forcefield.
    You're now going to want to make a new solid (comp size) and apply the "Fractal Noise" effect (effect > noise & grain > fractal noise).
    Make these changes to it (not the ones shown on the left): set the "Fractal Type" to "Strings", set the "Noise Type" to "Spline", set the "Complexity" to 1, and bring the scale (for the noise not for the layer) down to around 20.
    Change the layer's blend mode to screen.
    Keyframe the evolution twice so it increases during the shot about 315 degrees a second.
    Now, apply the "CC Sphere" effect to the layer (effect > perspective > cc sphere).
    Make the changes shown to the "CC Sphere" effect, except the radius and offset.
    Apply the "Color Balance" effect.  Check the "Preserve Luminosity" box and change the color of your forcefield.  For mine I turned the Blue Midtones and Highlights up to 100.
    Now you can resize the forcefield and use the offset control to position it over your character.
    You can now pre-compose the layer and check the move all attributes... box.
    What I did next was, in the main comp, masked off the bottom section of the forcefield to make it look like it went into the ground (shown).  Then I feathered it about 10 pixels.
    Apply the "Glow" effect (effect > stylize > glow) and make the following changes (bottom).  Then duplicate the effect three times, each time doubling the "Radius" from the one before.
    Now, go to the first frame you want the forcefield to be fully "formed" and apply the "Directional Blur" effect (effect > blur & sharpen > directional blur) and set a keyframe for the "Blur Length" at zero and move back to the frame the forcefield starts to form and blur it out a lot.
    Half way between the keyframes you just made, set one for the layer's opacity.  Then go back to the first keyframe and set the opacity to zero.

    Well, the final third (finally).
    Make two solids (comp size, any color).
    Apply "Trapcode's Particular" to one of them.
    Turn on the 3D layer switch for the other and, using the 3D rotation and position controls, match the angle and position of the floor.  You can scale it up if you like but it doesn't matter.  Once that's done, lock the layer if you want.
    Go two frames before the lightning hits the forcefield, set the "Particles Per Second" to zero, and hit the stopwatch for it.
    Go forward one frame and set it to about 2,000.
    Move the emitter to where the forcefield and lightning meet.
    Set the "Particle Size" to around 2 and mess around with the gravity and other physics until they are to your liking.
    Under "Physics" change the "Physics Model" from "Air" to "Bounce".
    Twirl down the "Bounce" settings and set the "Floor Layer" to the solid that is matched up with the ground.
    A new light will be created, telling the particle system how to use the floor.
    Change the "Floor Mode" to "Infinite Plane".
    Set the "Collision Event" to "Stick".
    Now, just like with the lightning, pre-compose, duplicate, blur, pre-compose, colorize.  But, be sure that when you first pre-compose you pre-compose the particle layer, the floor and the light.
    Now you're pretty much done.
    Another thing you can do, though, is to wiggle the emitter a little to make the particle spray seem a little more random.