Workflows to help conquer difficult tracks in Mocha
Continuing on with my learning up on Planar tracking and Mocha, I’ve come across two factors thta can adversely effect a track. Namely reflective surfaces and drifting. Good news though, for I quickly learnt some techniques to minize such things! Please… read on…
Surface Reflections Throwing of a Track
For a reflective sufrace, use a Cutout exclude refletcive area from the Planar Track. Check out the following images for a brief explaination.
Fixing Drifting Throughout Your Track Using “Adjust Track” Mode
Often times a track will drift off target as it moves through the shot. In this case you can use Mocha’s “Adjust Track” feature to nudge the track back on target.
My workflow for doing this is as follows:
1.) Identify the last frame in which your tracked surface is undistorted. (Without any drifting)
2.) Make sure that the “Surface” cornder pins are in place to specify the surface you wish to insert/replace.
3.) Click to enable Mocha’s “Adjust Track” feature. Mocha will then generate 4 red ‘X’s, one at each Surface corner pin. Position these new markers over 4 easily identifyable features on you footage (High contrast areas work best). These 4 red X’s will form the reference points from which mocha will then base your future adjustment tweaks/keyframes to. The offset between the reference markers and the blue Surface corner pins will be maintained – the general procedure is to keyframe animate the position of the red markers, to bump the track in the right direction.
There should also be a keyframe marked on your timeline , this is referred to as the “master frame”.
4.) On your timeline move to where distortion / drift is at it’s worst, and reposition the 4 red markers so they are accurately positioned ontop of what you placed them on top of in step #3. (On top of the same object that they were in the “Master Frame”.
5.) “In-between animate the sections where drift still remains – eventually drift will be minimized!
Check out the following video for a summary of the two planar tracking techniques I’ve described above.
Stay tuned for more!