[Bf-committers] NLA negative clipping bug

Fabrizio ilac at maltanet.net
Sat Jun 4 17:59:41 CEST 2005

NLA 'strip start' and 'action start' clip at frame 1

 The problem is that we are no longer able to set 'Action start' or Strip
start' to a negative value which was possible pre 2.36. Removed feature but
also also offically a bug because it's not backward compatable with files
created pre 2.36 that had negative starting points.

Importance of negative Strip start:
This is important as one sometimes need to sart the Strip from a negative
value. As it is, it simply clips your strip to one (even when opening old
files). This doesn't make sense as Action length is mapped to Strip
ength  - therefore shortening the strip shortens the 'period' over which the
action happens (faster). One has to clip the action for them to happen at
the same time but this is not easy when the ratio is not 1:1 - which is part
of the point having NLA strips to begin with. Moving the whole timeline is
also not always an option or (even an easy) as little data is available in
the NLA  and so there are several time-related issues such as movie
textures, particles, RVKS. time remappping etc which make this a VERY
complex task.

Importance of negative Action start:
'Hold' works forward not backwards so to 'hold' a position backwards we have
to set action to start much earlier than the first keyframe (Not a problem
as IPO's values work indefinetly back and forward) but if the action starts
from 1 you can no longer put the 'hold' space before the action. And moving
the whole action is tediuos if it is used by other armatures too.

So please could we have the ability to use 'negative values' back in the NLA
in with the imminent  2.37 bug fix release?

The NLA is limited enough as it is. I know the NLA is up for a re-vamp
together with the animation features  but that's a whole release away - and
proably a long one due to the animation refactor ( Speaking of which - look
to the adobe Aftereffects timeline for NLA inspiration - it truly is a
marvelous example of a what a timeline should be when it comes to features
and control! Hope to have some time for a proposal over coming weeks!)

versions affected:
bf 2.36
bf 2.37

OS: Winxp home ed



ps. Try as I might, I still can't log in to bug tracker (Yes, I've changed
my password as instructed) so sending bug report to bf mail-list. Excuse the
intrusion. Thanks

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