Chromanator Tutorials: Animation
Creating artificial movement
Something that is not always immediately apparent when starting to use compositing tricks is that you no longer need to capture all the movement in the camera itself. Movement can be augmented in Chromanator by moving the different elements of the shot around the screen using the animation tools. For example, you can film an actor against a greenscreen with very little movement, then composite him against the sky and make it seem like he is moving across the screen at a great speed.
There are a few things to bear in mind:
- If you are shooting against a greenscreen, be sure to have the entirety of the subject within the frame at all times. If any part of the subject is off-frame, you will be restricted in your positioning of the element, as the missing part will be obvious.
- If you are planning on manually separating an actor from the rest of the scene using a garbage matte, be sure to have a clean background plate. Otherwise, when you reposition the actor, an ugly ‘hole' will be left in the scenery. A background plate can be used to fill in this hole.
- When shooting the separate elements, pay close attention to lighting in each. If the lighting does not match, the composite will be obvious.
For this example, I'll create a fireball that races across the screen. Rather than trying to actually throw a fireball anywhere, let alone towards our actor, I can use stock footage of explosions and flame to create the illusion of a large ball of fire. The fire elements need to be filmed carefully against a black backdrop and preferably need to be fixed in the centre of the frame:
We now take a live action plate of an actor reacting to the non-existent ball of fire and find the appropriate place to insert the flame effect:
Any object that is primarily light-based (such as fire, lightswords etc) should be composited using the ‘Add' composite method, which can be found in the object's Properties dialog.
- An object's properties can be viewed by displaying its menu on the Project View timeline and selecting Properties.
- Change the composite method to ‘Add'.
The fireball is now composited correctly, but it is still just remaining stationary in the middle of the screen. It is time to switch to the animation toolset by selecting the fireball object on the timeline and pressing the Object View button (bottom left of the screen). Clicking on the Animate tab displays the animation tools.
I want the fireball to be descending from the top left of the screen, so the first thing to do is move it off-screen by dragging the centre handle across the canvas. The canvas itself can be moved around the screen using the right mouse button, if necessary:
If I now move the playhead forwards to an appropriate point, I can reposition the fireball as if it is about to hit the ground. To give the impression of it moving away from the camera, it can be shrunk by right-dragging on the centre handle or using the scale slider in the toolbox:
As you can see, keyframes only exist on the frames where we moved the effect. Chromanator will automatically ‘tween' the frames between each keyframe, creating a smooth animation from one keyframe to the next. You can move to other frames and add more keyframes if necessary.
When using stock footage, such as explosions, the overall effect can often be improved by combining several different clips to create a 'new' explosion. Using Chromanator's grading and effects tools many different results can be achieved using the same footage. In this example video you can see the results of using three explosions together, the box blur RGBA tool to create a slightly gaseous impact effect and a simple mask on the crate.
Download the example video.