[Soc-2017-dev] Weekly Report #11 - Silhouette Operator

[Sebastian Witt]

**

*Weekly Report #11 - Silhouette Operator*

*

Week 11 is now over and the deadline approaches rapidly. With only two 
weeks to go, the Silhouette Operator needs to be done soon.

At the end of last week I had multiple issues and problems. Finding 
solutions for them was the first thing I did this week.


The mesh problem

In sculpting mode operations manipulate the base mesh structure. Without 
Bmesh it is a challenge to edit the topology. After discussing, we came 
to the conclusion that it is best to manipulate the mesh via the 
CustomData Api. I was able to implement a function which remaps the 
customdata arrays and allows the necessary behavior. I only need to 
design an undo/redo node to support those changes.


The orthographic matrix

I was able to get the correct projections by first projecting onto an 
orthographic plane and then project to 2D.


After solving both problems I continued to work on the intersection 
calculation.

Last week i had already implemented a method to calculate the 
intersecting parts within the existing mesh. Relying on the result of 
this, I designed an algorithm to calculate the intersecting edges of the 
silhouette parts.

Even though the algorithm delivers a precise result, it is currently 
very slow. I am hoping that i will be able to improve its performance in 
a later optimization step.


*The idea* is: Calculate two loops. One loop on the existing mesh and 
one loop on the silhouette. Then connect both loops smoothly while still 
passing the precise intersection loop.

Today i started to implement a method to calculate the interior and 
exterior vertices. In theoryi can easily implement a clipping tool by 
just flipping interior and exterior. A later subtractive mode for the 
tool will be rather quick to implement.


The Plan is set and I hope I will be able to finish implementing this 
feature as soon as possible!

**

Sebastian Witt

*

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.blender.org/pipermail/soc-2017-dev/attachments/20170811/92561752/attachment.htm