[Bf-committers] Python API for updated data and other questions

[Angus Hollands]

Hi all, I'd like to keep this short, because it's early in the morning, and
I need to sleep, but there are a couple of questions I have regarding the
Python API.

We currently have is_updated as a means for testing if data has been
changed since we last rendered it. I am working/ discussing with someone
who is looking to integrate an external game engine into Blender, with
Blender as an interactive editor using the 3D viewport, and it seems that
in a number of cases, is_updated does not seem to be functioning
(/correctly?). Furthermore, it seems that in some cases, view_update and
view_draw are not being called by Blender when they ought to be.

I appreciate that these concerns are not supported by example files, or
implementations, but this is more of a higher-level question. is_updated is
currently confined to a select group of Python objects, and doesn't seem to
extend upon the basic idea that the Blender RNA API that all fundamental
data possesses. To my mind, it seems sensible that if data is modified, it
is tagged on a per-DNA-item basis, rather than manually (it seems, please
note I have not confirmed this in the source) implemented basis.

Some solutions that other applications use to track data changes is a
sequence number that represent an individual state. This might be a better
solution, but does not address the question of discrete state changes which
are necessary to identify to avoid brute force data comparison.

Any comments on the subject would be highly appreciated.

Regards,

Angus Hollands

[Posted in bf-python-request and bf-committers]