[Soc-2016-dev] Weekly Report #01, Mantaflow Liquids

[Sebastián Barschkis]

Hello everyone,

my report for week #01 on my progress with the Mantaflow liquids is up. You can
read it on my progress page:

https://wiki.blender.org/index.php/User:Sebbas/GSoC_2016/Reports/Week_1

Or you can also read the unformatted version in this email:

= Week 1 =

=== What's been done ===

* Some cleanup in my 'fluid-mantaflow' branch. Merged master and removed
deprecated smoke code. Some Scons files where still there too.

* It turns out that my prototype did not scale very well: Loading the fluid
objects in the form of .obj into Mantaflow can become ugly (you'd have that
.obj file somewhere on disk) and might underperform. Especially when dealing
with large meshes. I discussed this with my mentor and he advised me to just
fill up a levelset grid which indicates what's inside and what's outside the
mesh (e.g. -1 in and 1 outside).

* So I tinkered with my best friend smoke.c and used the BVH trees to calculate
such a map. To load it into Mantaflow I used the same structures I am using
with all the smoke & fire grids.

=== Next up ===

* Discuss my approach to create a "map of points indicating points inside and
outside a mesh" on IRC. My implementation works but I feel there might already
exist a function or so for that (which I'm just not aware of).
* Clean up smoke.c so that smoke & fire work again. I had to disable a lot for
liquids to work.

=== Questions ===

* How problematic is it to "kill" a physics modifier (backwards compatibility,
issues in .blend files)? I am thinking of totally removing the "Fluid" modifier
and repurposing the smoke code to work for liquids as well.

Best wishes,
Sebastián