Andrea, indeed a ‘zero-data’ keyframe is always installed at keyframe 0 the first time animation is introduced to some object. There is (currently) no ‘option’ to e.g. change the zero-data-keyframe’s default number or make it relative to the initial keyframe.
You can however easily move the zero keyframe by dragging it over the timeline. Automatically a copy is made hence leaving the original zero keyframe at zero.
Indeed David this can coincide with previous data. In a displaced copy of the keyframe 0 (e.g. at tick 50) you can easily filter out the desired parameter by unmarking the checkbox.
To make an unanimated object’s transition ‘start’ at a certain keyframe I mostly use the following technique:
• Place the timelineslider at the desired start-tick
• In Animation Mode select the desired transformation mode (Position, Rotation, …) in the timeline selection buttons.
• Then click in succession on the up and down spin button of the inputbox for the desired direction (X, Y or Z) hence introducing briefly a 1 value keyframe at the spot and setting it back to zero.
• Finally move the timelineslider to the ‘end-of action’ tick to make the final input.
Maybe the plus/minus clicking on the spin button in the technique explained above could be avoided by making a simple keyboard Enter sufficient to set the zero value. I’ll make an entry on the wish list.
At present we have a right-click anywhere on the timeline allowing to add a keyframe either Empty or Precalcutated. This can be used on an unanimated object as well, giving more or less the technique you described. More or less because indeed Bongo needs to now for which transition the keyframe is needed – there are not only the 9 transformation parameters but also the object’s attributes and material properties. So after installing an ‘Empty’ keyframe you need to open the Keyframe editor (double-click on the keyframe) and mark the desired parameter.
I cannot easily think of a way to make this more simple. Adding a ‘Zero’ option in the ‘Add keyframe’ list (besides ‘Empty’ and ‘Precalculated’) followed by a next context menu allowing the user to pick the desired parameter might be an option?