Episode II-III style Lightsaber rotoscoping
in Adobe After Effects

by Jon Carling

In Star Wars Episodes II and III a distinctive style of lightsaber blade was developed that is different from the other movies. This tutorial shows you how to reproduce this new style in Adobe After Effects. I use version 6.0 but it is probably adaptable to other versions.

Observations
There are five conventions of lightsaber blades that can be seen by looking at the available footage (for me that means trailers, but if you are reading this after the DVD comes out then you have access to some much better reference!):
1. Strong colour

Blades have a very strong colour and clear definition between solid white core and coloured glow.
2. Ignition/retraction flare

There is a short lens flare when a blade ignites or retracts.
3. Emitter glow

For static shots (especially close-ups) there is a wider glow at the emitter than along the rest of the blade
4. Pointed tip

Blade has a rounded-off point at the tip
5. Masked glow

Both the core AND the glow of a blade are masked by obstructions - including the edge of the screen. There is sometimes a bit of spill into the object used for dramatic shots.

OK now let's get on with the tutorial.

Setup
Open After Effects and import your source footage. Go to File>New Comp From Selection...

Name the layer 'Source' and set its quality to best.
Create a new solid. Make it white and click Make Comp Size. If the blade goes out of picture for any part of the footage make the solid larger than the comp - this is to preserve the correct glow effect.
Call the layer 'core', set its quality to best and hide it.
Call the composition 'blade' (or blade 1, 2, 3 etc. if there are more blades in shot)

Rotoscoping
Making sure 'core' is selected, create a mask that best fits the shape of the blade using the pen tool. I usually use a mask of six points, three at the base and three at the tip.

Click the core layer's hierarchy in the timeline and open the Masks spinney. Open up Mask 1 and click the stopwatch for Mask Shape.

Skip through each frame (using page down) and move each of the mask points to fit the blade.

IMPORTANT: Where the blade is partially or totally obscured you must mask where the blade actually IS - this may mean guessing. See the following examples:

This must be done even when the blade is totally obscured, as the chances are the glow will protrude outside the edges of the obstruction.
Continue until you reach the end of the shot. It can sometimes be a good idea to add a median effect of about 1 or 2 and checking the act on alpha channel box to round off the edges of the blade.

Producing the glow
Here is a diagram showing the anatomy of an EPIII saber glow:

Moving from the middle to the edge:
1. Inner core
2. Outer core
3. Glow
Also, as I mentioned before, there is a larger glow near the emitter.

Delete the source layer (we only needed it for reference) and replace it with a black solid.
Unhide the core layer and duplicate it, calling one layer 'inner core' the other 'outer core'.
Feather the outer core layer to match a reference picture such as that above. Good reference material can be got from the trailers or DVDs.
Duplicate the inner core layer and name the new layer 'glow'. Place it underneath the core layers.
Change the colour of the glow layer to the colour of your saber - you can always adjust this later.

If you want to produce a larger emitter glow then this is the point to do it (see later section for instructions).

Apply a Gaussian Blur effect to the glow layer. Adjust the size of the blur and the expansion of the glow layer's mask to achieve a nice glow. The settings depend on the distance of the camera from the saber, the size/resolution of your footage and the effect you want to create. Basically, fiddle with settings until it looks cool.

Compositing
Create a new composition from the source footage and set its quality to best. Nest the blade comp into your new comp, set its quality to best and its transfer mode to screen. Et voila! A saber. Play around with colour settings, blur/feather sizes and different transfer modes until you get a good shot.
The final step is to mask off the obstructions (this does not apply if your shot had the saber always in the foreground).
Set the blade layer at 50% opacity so you can see the footage underneath it. Find the frames where the obstruction should occur and draw a mask on the blade layer that follows the shape of the obstruction - in this case Hayden's head:

It is useful to turn on 'RotoBezier' for this.
Set the mask to Subtract and put the layer's opacity back to 100%. It is also usually good to play with the feather and expansion values to find the right level of light spill.
This mask should only exist on one frame, so click the mask's Shape stopwatch, the hit page up to go to the previous frame and drag the whole mask way out of the shot, then hit page down twice to go one frame after the obstruction and again move the mask out of the way. You may also be able to use the same mask for more than one obstruction frames, by moving the points to the new shape.

Extra effects: pointed tip
This is very simple. At the rotoscoping stage, for the frames where you wish to add a tip, just pull up the middle of the three tip points and adjust to get the right shape.

Extra effects: Ignition flare
Find a nice flare image (from the net or create one) and use colour balance to match the colour of your saber, then screen it on top of your shot at the point of ignition and animate its position to align with the emitter. Animate it's size parameter to grow then shrink over about 5-7 frames. If the emitter is moving very fast it is often useful to add motion blur to the flare.

Extra effects: Pulsing
For a pulsing effect useful for static, close up shots, on your blade comp add a Slider Control effect to a null layer or the background black layer.
Add an Expression to this control (Animation menu) and type in gaussRandom(-5,5) - you can replace 5 with a number that suits your shot later.
Add an expression to the expansion property of the mask of a core or glow layer. Add to the default expression (which is 'mask("Mask 1").maskExpansion') a plus sign ('+') and then use the pick whip to chose the slider control. Do this for the expansion property of all the layers. Preview the animation and adjust the numbers in the slider control's expression to achieve a good effect.

Extra effects: Emitter glow
Do this before you apply the gaussian blur to the glow layer.
Hide the core layers. Duplicate the glow layer's mask and call one mask 'blade glow' the other 'emit glow'. Using the elliptical mask tool add a circle that surrounds the emitter. Call this mask 'emit glow circle'. Animate this mask's shape parameter so it always follows the emitter. Now drag the masks so they are in this order: emit glow, emit glow circle, blade glow. Change the emit glow circle mask to Intersect.

Increase the expansion of the emit glow layer and you should see something like this:

Play with the feather and expansion settings of the emit glow and emit glow circle masks to get something like this:

Now when the gaussian blur is applied and the other layers unhidden you have a nice emitter glow (I have exaggerated it here for example purposes):

Any other things I can mention? Ah yes clashes. Just add a nice lens flare (Ryan W has a nice one you can download from his site) at the point of contact.

FINAL THOUGHT THINGY:
The best way to achieve a good saber blade is to play around with as many settings as possible while referring to some reference footage until you get a good looking effect.

Good luck!

.jon