Explosive Effects

Creating Custom Transitions with Video Action

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.

Shading1_320.jpg (19948 bytes)

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.)



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.)


Have fun!

Click the image above to see an mpeg
clip of the effect in 'Action'!

You can find out more information about Video Action for PVR and EditBAY at http://www.dps.com.

The author welcomes questions and comments. He can be reached by email at [email protected]

About DPS Video Action
Video Action for Windows NT is the professional’s choice for broadcast quality digital video editing. Together with DPS’ award winning hardware Video Action delivers a full featured editing solution. The software package comes bundled with all of DPS’ desktop products – DPS EditBay, DPS SparkPlus, DPS Perception, and DPS’ real-time editing solutions the DPS Perception RT and DPS Perception RT3DX. The power of this software is apparent when it is combined with DPS’ award winning hardware. DPS Video Action software makes it easy to move from one DPS hardware platform to another without the need to learn a new editing program or user interface.

About DPS
About DPS – DPS is a leading designer and manufacturer of electronic hardware and related software used for recording, editing and processing broadcast quality video and audio material. The company has three business segments: Broadcast, Professional Post-Production, and Security. DPS products are used throughout the world by television broadcasters, video production studios, post-production facilities and by the computer-based desktop video production industry. Visit our web site at www.dps.com.