I am starting to work with Mocha and realise it is a very powerful tool. I am looking to understand the purpose and effect of the various options in the 'Motion' section (e.g. Translation, Scale, Rotation etc.) I have read the manual and watched some tutorials, but I cannot find anything that explains (a) the purpose of each option, but more importantly, (b) what effect each of these settings has on the tracking. When should I enable/disable these settings? What is the impact of each of these settings on the track?
Any pointers to tutorials, videos or further info very much appreciated.
That will really go over the planar tracker in depth and give you a lot of information about the tracking parameters. It's a great resource. And is discusses when to use each setting. Basically translation is to grab X & Y data, scale and rotation are pretty self explanatory, if the object is scaling or rotating, use those options, shear is just a warp in X & Y like a square becoming a diamond, and perspective is the addition of Z Space warping to your object, like a door opening or a face turning away from you. You only use what parameters correspond to the motion of the plane you are trying to track.
You may also want to check out the Getting Started With Mocha series by Ben Brownlee, it's on our website at borisfx.com and streams for free. If you want to purchase it in HD, that is also an option. Here's an example of tracking basics from Ben Brownlee: https://borisfx.com/videos/mocha-pro-2019-whats-new-/