Create a bottom aligned triangle.

• Tools -> Roto -> Bottom triangle

• A Roto node with a bottom aligned triangle is created.

• Copy 'bottomTriangle' folder in your .Natron folder.
• Add following lines to your 'initGui.py' file, where <path> is the location of 'bottomTriangle' folder.

from <path>.bottomTriangle.bottomTriangle import *
NatronGui.natron.addMenuCommand('Tools/Roto/Bottom Triangle','bottomTriangle()')