you can fly!?
PD Pro Digital Painter, and Project Dogwaffle Professional:

Motion Tracking !
with the Brush Keyframer
more: what's new in 3.6?
take me back





















before...








after...









Try it for yourself with your full version of
PD Pro 3.6:

get the brush...
(zipped .tga file with shadow
transparency in alpha channel)



Motion tracking is new in PD Pro 3.6

Animated Skies -


- Mars
or click here for to track the Sun during a hasty descent and landing on mars. It's turbulent, and the Sun swings back and forth during the animation. But we're able to track it and place another brush image on it, such as that of a bright bloom or animated brush with animated streaks.



tracking a star
Buzz - Tracking a faint star to make it brighter








Motion Tracking 101

 - Phase 1:

Here we have a brush of a sphere (possibly rendered in a 3D program or painted with gradients in PD Pro). It casts a nice soft shadow, and uses an alpha mask so we can use it for composition over another image or video.

An original video clip of a walk through the forests is shown too. It was also loaded and stored into a custom animated brush for easy re-using. Next to it there's also a version with the finished motion tracked sphere rendered over it.

The main view shows an arrow pointing to the area where we'll start the tracking. It's there only for illustration purposes. When we enter the Brush Keyframer, we will place the brush there.





























use Brush>Store&manage...
to keep it ready for use.

brush loaded and ready




 - Phase 2:

Here we are using the Brush keyframer. The original movie clip was loaded first, and after entering the keyframer we get the current brush (a custom brush, in this case of that sphere with shadow). We place it in the desired start position for the first frame, and hit ENTER (or click the 'add keyframe' icon).

Then we scrub to the last frame, and noticing where the selected area of the moving path in the video has advanced to, we click that area to drag the brush to it. You can also adjust the scale of the brush to accomodate for the enlargement due to perspective distance.

After keyframing the end position, you're ready to enter the motion tracking. It's in the "Special" menu of the keyframer.





 - Phase 3:

When you enter the "Track Point" feature, you'll have access to two sliders:
  1. The Search Area: This is a larger box, in which a small box is expected to be found. The smaller box contains the pixels of interest that will be searched (tracked)
  2. The Block Size:  that's the block of pixels we're trying to track. It is best if there's an item inside that small block which is of high contracts and marked shape, like a cross or dot, black on white or something else easily tracked with Fourrier transform and Convolution math. By contrast, a general white noise area will be impossible to track.
In this current first release, the boxes of the search and block areas are not shown in the keyframer until you start tracking. So use the default values or a reasonable guestimate for how big to make these. The block area should always be smaller than the seaerch area.

Click on "Track" and the keyframer will start tracking the selected area found under the start position from the first keyframe.





 - Phase 4:

During the tracking, you'll see two nested red boxes. The inner. smaller area is indicating what it's looking for. The outer larger box is the search area in which it hopes to find it at the next frame.

Eventually, the whole path is found (unless the trace has been lost).




 - Phase 5:

If the tracking was successful then you'll see an updated and useable path. The white spline path you normally manually create by way of manual tracking will have been replaced with the new one.

In this example below we lost the tracking, as you can see that the path is a short curve and didn't extend through where we expected it to go based on initial estimates and start and end keyframes.

That's ok, we try again, refining the size of the track box perhaps to a small area, or selecting a clearer item and group of pixels, such as a bright rock near a dark shadow.  The better the contrast, the better the chance of successful tracking.

At the bottom of the brush keyframer, you'll notice a lot of red tickmarks. These are the recorded positions of the motion path detected by the motion tracker (whether usable or not). You can certainly remove some back keys there or modify their parameters, for example to change opacity or size. But keep in mind that much of that can also be done through the contact of the brush image itself which we're about to render along that new path.  In particular, the brush image can be an animation, so the size, color, shape and opacity and other details can be made to change that way.





- Final Phase:  use the tracking path for rendering


You will then finally use the "Render" button in the keyframer in order to start rendering the brush along that path. You can then 'Get' another brush and render along that same path. Perhaps for a glow/burn effect or smoke trals, with lots of motion blur to fake a smoke trail.

Before: the original clip was 640x480 large and a bit fuzzy. Here we show a smaller version, resampled down to 320x240 in PD Pro and also time-extended from 79 to 100 frames and playing at 24 fps: 

< Flash Version  or: Avi-Xvid version: motrack_before.avi





After: the result of using the automated new motion tracking of PD Pro 3.6 and rendering the brush along the path created by the tracker.

< Flash Version  or: Avi-Xvid version: motrack_after.avi








Tracking an area on a Moving Sky

sample sky
Here's something that we start as a simple static image: some sort of nebulous plasma-noise based sky from outer space perhaps?



You can create an animation with a bunch of frames that are duplicates of this initial image. So far no motion.

Then you can use the Timeline editor to apply the Transform filter and add a change in scale and sideways 'pan'.

You can also add  rotation. In a few seconds, you might have this:




tracking an area of this animation is not difficult if you want to do it manually, but it's not trivial either.

Using the automated motion tracker: In this case we just start the brush somewhere (no brush really needed at this point so we used something that we turned very small or transparent. Not in the keyframer, but in the custom brush itself. Or if the image of the brush is a set of black pixels, using 'add' mode won't change a thing. So the brush doesn't get in your way of preceisely picking the starting point.

Here's the tracking in progress...


The tracking is completed. A path has been found. This one was from the first animation (panning only, no rotation)



Load any custom brush, even animated brush. If you want you can use the internal brushes and simply convert tem to custom format.  Or create an animated version of a new brush from a static custom brush image. Or use the FXbrush tool to make animated flares with streaks that turn and change intensity with noise and more.

And click 'Get Brush' in the Brush Keyframer. Render the brush in Additive or whichever desired mode you want.

Use the brush>Store/Manage... featur to change intensity and color of the final brush before sending it into the keyframer for rendering. So, even if the path was generated and has a lock down on the opacity and rotation, you can apply additional transform through what's in the image sequence used by the brush.




Loading another brush or rerendering the same can add intensity. In this case we used a large bloom that was created with the Nova tool from the Linear toolset.  It was drawn against a black backdrop in the Swap buffer and  picked up as a custom brush, chromakeyed to back background for transparency around it, and rendered in additive mode.



   Mars landing

A rather challenging endeavour:  landing on Mars. Thanks to Carrara it's possible to imagine it and similate what it might look like to arrive in a capsule with a parachute or last-second thrusters stopping you short of crashing. The descent might experience a few turbulences.


original animation.

As you try to keep your sights at the Sun, it will wiggle and wave left to right and up or down. This is a good one for a motion tracker, becaue while it is not impossible to track it post-mortem manually, it would be tedious. As long as the bright Sun remains in trhe field of view we have a chance of  tracking it and locking on it so as to generate a path for a new brush to be rendered along it.

Before using the brush keyframer's motion tracker, we might want to apply a few filters, perhaps to increase contrast, or add a fog/grey filter in the lower half and a red-sunset filter in the upper half. The Timeline editor can be used for a variety of effects across the frames of the animation.

the enhanced animation, before motion tracking but after some
changes done with the Timeline editor.


On to the Motion Tracker. Here's a snapshot of the tracker at work.


the tracker is done: a strange path was found for
the Sun, which is what we asked it to track



rendered a brush across the path created by motion tracking the Sun

you can now load a desired fx brush, and render it along that path. Some fine tuning might be needed at times, such as if it lost the tracking for some of the path. Or if in fact there are things in front, obscuring the sun, such as clouds, or UFOs  :-)

Finally, you may want to show some special fx which are coming from the extreme cold and radiation. Perhaps we're not receiving a very good signal, and the electronics is about to go bust. We can also easily extend the clip by adding more frames which are replicas of the last frame, and then do some more post work like noise, video lines, deformations to indicate thermal distress to the opcical system of the camera etc...  and of course the final fade out to black with just a little bit of static.

failed martian landing
a failed martian landing... costing a typical tax payer only $146.95
($97 for PD Pro and $49.95 for Carrara Studio 3)