By Paul
M. Grossman
Today we will be looking at creating another rather unique
effect, an exploding transition. You may recall seeing this
effect in the trailer for the movie Shattered. The video
screen breaks into bits like a broken sheet of glass. You can
use Video Action’s Explosion filter to go beyond the broken
glass effect. Our client is doing a promotion of an upcoming
3D Jigsaw Puzzle Exposition. They ask for a custom transition
for the spot that takes the video and blows it up into several
jigsaw puzzle pieces like this.
This is a two part project. Before we get to the filter, we
need to create a fragmentation map of the exploding pieces.
Here are three examples of fragmentation maps. The first mask,
called Frags.bmp, can be found under the Video Action Samples/Masks
directory. The second is a sample broken glass map. The third
is the map of puzzle pieces for this project.
Each piece is a flat shade of gray. There are a few things
to keep in mind when creating a fragmentation map. First, if
two pieces have the same gray value the will fly along the same
path. Second, although you can have up to 256 shades, more flying
pieces means more rendering time. The Puzzle30 image has about
thirty five flying pieces. Lastly, don’t use pure black.
It is reserved for creating a single layer alpha channel and
will render transparent.
Almost any paint program can be used to create a fragmentation
map. My personal favorite is the demo version of Matisse
Paint originally by Fauve Software before it was sold to
Macromedia. The demo outputs only in grayscale, which is perfect
for this type of work. It is available, as of this writing,
in America Online’s software archives.
Once the mask is created, the effect will be completed within
Video Action. The mask itself will not be in the Gallery. This
is a custom transition so we will use the Transition Wizard
to create it. Bring two clips to the timeline and create a transition
between tracks V1 and V2. Right-click on the transition and
select the Transition Wizard under the Rendered Transitions
sub-menu.
The transition Wizard shows the A and B clips in the transition,
and features several options. Different advanced effects can
be applied to both clips to achieve complex transitions. Don’t
worry about these extra options for now. All we want to do is
add an Explosion filter to the ‘A’ clip by clicking
the ‘FX on A Clip…’ button.
Next select the Explosion filter from the list on the Apply
Effects dialog.
The Explosion Filter dialog will now appear and the Preview
window will be black. Don’t worry, this is normal. Slide
the Phase slider to 0, choose ‘3D preset’ and choose
‘Random’ for Blast Direction. This gives a good looking
blast effect.
Click the Fragmentation Map ‘File…‘ button and
select the filter mask to use. The mask will appear in the small
window and the preview window will display the image to be exploded.
Next, click the ‘Keyframe’ button. Move the keyframe
slider to 100 % and then change the Phase slider to 100. Phase
is the percentage of the paths the pieces have traveled. Move
the keyframe slider to the middle and you will see a totally
destructive image.
Tip: You can choose to have more of a gravitational pull on
the pieces. On the last keyframe, drag the red bullseye target
in the preview window to the top of the screen.
Make it shine!
The effect is interesting at this point. We could let go at
that. But at the cost of a little extra rendering time you can
add shine and shadow to give the pieces depth.
The shine comes from adding the Shading filter. Uncheck the
‘Use Original Clip’ option. Then move the red target
to the upper right corner.
Click the Keyframe button. Add a keyframe in the middle and
drag the red target from the upper right corner to the lower
left corner. This gives the slick, glossy look of glass reflecting
a light source.
The Shadow filter is easily added, and the only change it needs
is to set the Inner and Outer borders to 0.
The effect is ready to be rendered.
Here are the two fragmentation masks shown above to help get
you started. (To download the files hold down the shift key
and click on the name.)
Puzzle30.bmp
BrokenGlass.bmp
And here is the final filter macro for this project. If you
download the Puzzle30.bmp to the root of your C: drive, the
Explosion filter in the macro will find it automatically.
(To download the filter hold down the shift key and click on
the name.)
Explosion.flt
Have fun!
