This dragging zone is visualized as the circle (the same as object origin)
in the spline bounding box center and dragging that circle drags the whole
spline.
Pretty much basic functionality, but quite useful in practice.
Requested by our roto team (Sebastian and Sean :) in IRC.
This actually implements the idea used in Gimp which is grabbing
an arbitrary point on the spline and dragging it, ensuring spline
goes over this point. This is really useful way to tweak spline
curvature.
Currently only affects on a closest handle, meaning no weighting
on changes for both handles which are adjacent to the same segment
will happen just yet,
Another limitation is that currently such a slide is a big jumpy
when you start sliding. This is because projection is not used
to calculate u value because projection used to fail a lot for
me here and didn't find a nice solution for this yet. But this is
to be improved for sure!
Summary:
The title actually says it all, it's just possible to
have independent free handles for mask splines. Also
it's now possible to have aligned handles displayed
as independent handles.
Required changes in quite a few places, but they're
rather straightforward.
From user perspective there's one really visible change
which is removed Handle Type menu from the panel. With
asymmetric handles it's not clear which handle type to
display there. So now the only way to change handle type
is via V-key menu.
Rewrote normal evaluation function to make it deal
with new type of handles we support. Now it works in
the following way:
- Offset the original spline by maximal weight
- Calculate vector between corresponding U positions
on offset and original spline
- Normalize this vector.
Seems to be giving more adequate results and doesn't
tend to self-intersect as much as old behavior used to,
There're still some changes which needed to be done, but
which are planned for further patch:
- Support colors and handle size via themes.
- Make handles color-coded, just the same as done for
regular bezier splines in 3D viewport.
Additional changes to make roto workflow even better:
- Use circles to draw handles
- Support AA for handles
- Change click-create-drag to change curvature of the
spline instead of adjusting point position.
Reviewers: campbellbarton
CC: sebastian_k, hype, cronk
Differential Revision: http://developer.blender.org/D121
Allow duplicating splines from inactive layers. This way it's
more useful IMO than restricting duplication to an active layer.
TODO: What should be a behavior for clipboard (currently it copies
splines from an active layer only)?
So now it's possible to copy-paste splines between layers.
Implementation is pretty much straightforward and duplicates
some logic which we've got in sequencer/tracking clipboards.
Will work on a common routine for clipboards later, for now
it's not so much crucial to have.
