[Soc-2013-dev] Weekly Report #2: Cycles Motion Blur

[Gavin Howard]

All,

My report is at
http://wiki.blender.org/index.php/User:Gdh/GSoC-2013#Weekly_Report_.232:_Cycles_Motion_Blur.

This week was *very* frustrating for me. Soon after I sent my last
report, I got a compile error from trunk. I spent a lot of time trying
to figure it out. I ended up reinstalling my operating system because
I thought the libraries were corrupted. They were, but I also had to
get set up again.

In doing that, I ran into a problem because I used install_deps.sh to
get my dependencies. Now that Blender has moved to OpenEXR 2.0, I had
to compile it. Unfortunately, I link dynamically, and the computer
wouldn't run Blender because it couldn't find the .so file. I ended up
adding it to the config in /etc. To prevent other users from running
into that problem, I submitted a patch to modify install_deps.sh to
automatically add OpenEXR to the config. I know that I have commit
privileges, but I would only like to use them in my branch unless
given explicit permission. Please review my patch and see if it will
work.

Because I was fighting the compiler all week, I really got nothing
done. I finally got the compile working again earlier this evening.
Like I said, I am frustrated, but there's nothing I can do about it
but work harder next week.

However, I was able to do some thinking about the current state of the
Attribute class. I know about the AttributeStandard enum and two
options it has called ATTR_STD_MOTION_PRE and ATTR_STD_MOTION_POST.
Currently, under those, an Attribute only holds one mesh. Based on
suggestions by Brecht and Stuart, I was thinking of extending those
two to handle multiple meshes. The reason I want to keep them is that
steps before the frame need to be treated differently from steps after
the frame.

==== What I will do next week ====

Next week, I will be looking into the requirements of extending the
Attribute class. That will include diving into the code for the CPU
kernel. I need to figure out what changes need to be made there before
I have an idea of what I need to do. To be honest, I am pretty
frustrated with how little I have been able to get done by this point,
so my hope is to attack this thing next week. Hopefully, I'll be
writing code the next week.

==== Questions ====

First of all, please look at my patch
(http://projects.blender.org/tracker/index.php?func=detail&aid=35897&group_id=9&atid=127)
for adding OpenEXR config to install_deps.sh.

Also, I would like current devs to comment on my thoughts for
extending ATTR_STD_MOTION_PRE and ATTR_STD_MOTION_POST.

God Bless,
Gavin Howard