Operator to setup scene for camera tracking

This patch implements button called "Setup Tracking Scene". This button makes the following:
- Sets background to 3d viewports
- Makes camera be following solved camera (adds Camera Sovle constraint)
- Set ups render layers (foreground and background)
- Places sample objects into scene
- Makes nodes setup

Probably it can be cleaned up or simplified/optimized in some places.

P.S. There are some small improvements planned, but they aren't large and prefer to start reviewing patch sooner.

[ideasman42, 2011-11-22 14:36:08]

suggested edits for patch.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
File release/scripts/startup/bl_operators/clip.py (right):

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:30: def _set_background(space_v3d,
clip, user):
dont think _ prefix is useful here, funcs in funcs are always private.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:353: sc = context.space_data
(picky - but poll runs a lot) may as well add a the top and avoid multiple
getattrs

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:358: def _setupScene(self,
context):
utility funcs that dont use self can be @staticmethod's, same for other util
funcs which dont use self

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:403: # Remove all constraints to be
sure motion is fine
perhaps we should have an api function .clear(), py has this for dict's

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:417: def _findRenderLayer(self,
scene, name):
think this function isn't needed, or replae with 1 liner.

  return scene.render.layers.get(name)

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:470: if node.type in ['MOVIECLIP',
'MOVIEDISTORTION']:
(picky) use a set - {'MOVIECLIP', 'MOVIEDISTORTION'}

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:479: b.location[0] += 40
b.location += Vector((40.0, 20.0))

same for uses below.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:497: while len(tree.links):
# use this, py api optimizes for truth test on a collection.
while tree.links:
...

Another case where .clear() would be nice.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:673: if ob.type == 'MESH' and
ob.name == 'Ground':
Im not much a fan of doing name checks - perhaps chech mesh type and that it has
4 verts and 1 face?

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:679: all_layers = []
(picky) prefer LC's here, 1 liner...

return [(layers_a[i] | layers_b[i]) for i in range(len(layers_a))]

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:701: faces = [[0, 1, 2, 3],
(picky), prefer tuples for immutable seq's (unless you intend to modify later)

[sergey.vfx, 2011-11-23 12:45:31]

Fixed issues in local repo (can't reupload patch because it requires patch from
issue 5431052)

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
File release/scripts/startup/bl_operators/clip.py (right):

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:30: def _set_background(space_v3d,
clip, user):
Ok, removed

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:353: sc = context.space_data
Not sure understand you correct, but now "sc = .." moved above "if" and "if"
replaced with "if sc.type blablabla"

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:403: # Remove all constraints to be
sure motion is fine
.clear(0 was added in separated patch. Updated this code to use .clear

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:417: def _findRenderLayer(self,
scene, name):
Indeed. But think i can drop this function then and use
scene.render.layers.get(name) instead.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:470: if node.type in ['MOVIECLIP',
'MOVIEDISTORTION']:
Ok

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:479: b.location[0] += 40
Done

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:497: while len(tree.links):
Hrm. Think this clear isn't really needed.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:673: if ob.type == 'MESH' and
ob.name == 'Ground':
Don't think it'll work. "Ground" is creating by this script and this check was
added to prevent adding it several times. Artist can easily already have it's
own planes before running this script and in this case ground plane wouldn't be
created.
Probably custom properties can be used to distinguish automatically created
objects by script from objects, created by user

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:679: all_layers = []
One liners.. If you think it's easier to read, then ok :)

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:701: faces = [[0, 1, 2, 3],
In this case it's not intended to be changed.

[ideasman42, 2011-11-23 13:05:39]

a few replies for remaining issues.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
File release/scripts/startup/bl_operators/clip.py (right):

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:353: sc = context.space_data
On 2011/11/23 12:45:31, sergey.vfx wrote:
> Not sure understand you correct, but now "sc = .." moved above "if" and "if"
> replaced with "if sc.type blablabla"

Done.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:417: def _findRenderLayer(self,
scene, name):
On 2011/11/23 12:45:31, sergey.vfx wrote:
> Indeed. But think i can drop this function then and use
> scene.render.layers.get(name) instead.

Im not fussed if this function is simplified or replaced with
scene.render.layers.get, IMHO either is ok.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:497: while len(tree.links):
On 2011/11/23 12:45:31, sergey.vfx wrote:
> Hrm. Think this clear isn't really needed.

ok

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:673: if ob.type == 'MESH' and
ob.name == 'Ground':
On 2011/11/23 12:45:31, sergey.vfx wrote:
> Don't think it'll work. "Ground" is creating by this script and this check was
> added to prevent adding it several times. Artist can easily already have it's
> own planes before running this script and in this case ground plane wouldn't
be
> created.
> Probably custom properties can be used to distinguish automatically created
> objects by script from objects, created by user

agree, in that case tagging an object as being ground makes more sense though we
don't really have a precedent here.

obj["is_ground"] = True  # ?, maybe something like this.

http://codereview.appspot.com/5432048/diff/1/release/scripts/startup/bl_opera...
release/scripts/startup/bl_operators/clip.py:679: all_layers = []
On 2011/11/23 12:45:31, sergey.vfx wrote:
> One liners.. If you think it's easier to read, then ok :)

eeh, this is a bit subjective, I like LC's and this seems an appropriate use to
me, but some people complained about my code using LC's too much.

reminds me, would be nice to have boolean op support on boolean arrays so you
could just do (layers_a & layers_b) but thats for later.