[Soc-2013-dev] Weekly Report #7

[Daniel Stokes]

== Progress ==
I started this week by doing some touch up on the level of detail work from
earlier this summer and submitting a patch for it to the code review site:
https://codereview.appspot.com/12216043/

Overall bug hunting this week didn't go so well.

Added some documentation to the wiki to close 2 reports:
[#26391] Collision sensor fails to get triggered when colliding a Softbody
in GameEngine<https://projects.blender.org/tracker/index.php?func=detail&aid=26391&group_id=9&atid=306>
[#29792] bge.constraints 6DoF parameters (stiffness,damping,angle limit)
has no/strange influence<https://projects.blender.org/tracker/index.php?func=detail&aid=29792&group_id=9&atid=306>

Closed the following 3 bug reports for the reasons noted in the reports:
[#27265] 2.57b GE: Updating of debug Property display from linked scenes
not working<https://projects.blender.org/tracker/index.php?func=detail&aid=27265&group_id=9&atid=306>
[#32767] Object Properties do not hold correct
values<https://projects.blender.org/tracker/index.php?func=detail&aid=32767&group_id=9&atid=306>
[#36329] Character physics type doesn't react to
actuator?<https://projects.blender.org/tracker/index.php?func=detail&aid=36329&group_id=9&atid=306>

I have investigated 6 other reports:
[#29474] getScreenRay returns wrong objects with orthographic
camera<https://projects.blender.org/tracker/index.php?func=detail&aid=29474&group_id=9&atid=306>
As far as I can tell, this should work. However, adding a glReadPixels to
get the depth buffer for the gluUnProject in the getScreenVect function
that getScreenRay relies one does appear to correct the problem. The
problem with this solution is that glReadPixels was originally removed from
this function to fix another bug, and it also causes an OpenGL sync that
would be best to avoid.
[#32175] bge.texture.ImageRender alpha channel returns 255 for every
pixel<https://projects.blender.org/tracker/index.php?func=detail&aid=32175&group_id=9&atid=306>
This bug requires the use of a framebuffer with alpha bits. This feature
was added, but later removed in order to fix a bug. I have not yet done the
necessary follow up to figure out if we can have a framebuffer with alpha
without introducing bugs.
[#32470] localPosition giving world
coordinates<https://projects.blender.org/tracker/index.php?func=detail&aid=32470&group_id=9&atid=306>
This one seems kind of nasty. When a parent child relationship is
converted, the child's local transforms are not set. However, setting the
value during conversion seems to cause extra transformations to occur so
that the scene may not match between the viewport and the game engine,
which would be confusing and would break some existing set ups. I could
have screwed up the math here, so another look could be worthwhile.
[#33215] KX_MeshProxy.transformUV() argument
ValueError<https://projects.blender.org/tracker/index.php?func=detail&aid=33215&group_id=9&atid=306>
Fortunately this one looks simple, I just need to get in contact with
Campbell to ask him some questions about the features that raise the error
described in the report.
[#35454] Setting parameters on joints with softbodies causes blender to
crash<https://projects.blender.org/tracker/index.php?func=detail&aid=35454&group_id=9&atid=306>
This one occurs because the constraint wrapper only half supports soft
bodies. It will set up a relationship with a soft body, but it is not a
constraint and therefore returns an invalid constraint id to the wrapper.
Then when the wrapper tries to use the invalid constraint id, the crash
occurs. I have a patch that raises python exceptions whenever the wrapper
tries to perform an operation with an invalid id (and notes that this
occurs with soft bodies), but I am not sure yet if this is the best
approach to handle this report.
[#18987] alignAxisToVect() Factor
Bug<https://projects.blender.org/tracker/index.php?func=detail&aid=18987&group_id=9&atid=306>
We seem to have a lot of reports like this one. Not really a bug, but
something should probably be done. I have a patch that adds a note to the
function's documentation that points out that factor can cause undesired
behavior at angles near 180 degrees. I spent some time today figuring out
how to generate the docs to test my patch, and now I just need to double
check if this is the way we want to deal with this report.

For these reports I will be talking with my mentor and some of the other
developers to see how to best resolve them.

I have also flagged the following 2 reports for closing in one week for the
reasons noted in the reports:
[#19016] "Real" armature modifiers not
working<https://projects.blender.org/tracker/index.php?func=detail&aid=19016&group_id=9&atid=306>
[#19277] Mesh deform in views but not in game player, armitage moves
parented objs though<https://projects.blender.org/tracker/index.php?func=detail&aid=19277&group_id=9&atid=306>

This leaves only 5 reports closed with 8 in progress. There were other
reports that I looked at but I didn't start recording incomplete reports in
my log until later in the week, though I did post comments in reports as I
made discoveries. I spent a fair amount of time digging through game
engine's physics code trying to solve bugs, but I did not have much success
there (though I got a good tour of that part of the code base chasing these
bugs).

== Next Week ==
Since I am not doing so well with the bug hunting, next week I will work on
some of the community requested features. The first one I plan to work on
is getting the displace modifier working in the blenderplayer (this is also
reported as a bug). This requires some code reshuffling that could
potentially lead to procedural texture support in the game engine. I plan
to investigate the feasibility of adding procedural texture support, and if
it looks reasonable I will work on that. Otherwise I will move on to other
requested features as deemed appropriate by my mentor and other BGE
developers.

I also plan to follow up on some of the investigated reports mentioned in
the progress section, especially the last three listed.

== Questions/Problems ==
See the investigation results above :P
I will also be contacting some people specifically about some questions.

Hopefully next week is more successful.

Regards,
Daniel Stokes
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