NEW UI/WORKFLOW: Implement layers in Draw mode that can be displayed or hidden
From @sconklin on June 10, 2015 15:3
Originally reported by: Roman Telezhynskyi (Bitbucket: dismine, GitHub: dismine)

How we can see on image sleeve draw was rotated and above of two pattern pieces was drawn new pattern piece that use parts of both.
- Bitbucket: https://bitbucket.org/dismine/valentina/issue/312
Copied from original issue: valentina-project/vpo2#312
Original comment by Susan Spencer (Bitbucket: suzynumena, GitHub: Unknown):
Import multiple block patterns to base layer 0.
Join the block patterns together and establish connections between them in layer 1.
Make design changes in layer 2.
The Pattern file is saved from layer 2.
Original comment by Susan Spencer (Bitbucket: suzynumena, GitHub: Unknown):
This may be related to issue #[unknown]: Add 'Tracing Mode', in that it requires the definition of a base layer plus a design layer which overlays the base layer.
This is related to #51 Multidocument Mode, #52 Master pattern and derived pattern, and #53 : Add Rotate Pattern tool to manipulate the placement of pattern pieces in the base layer.
The user would open an existing pattern and assign it to the 'base' layer.
The user would rotate the pattern pieces in the 'base' layer.
The user cannot change the formulas in the 'base' layer (they can do this separately if needed, then open the changed pattern).
The user would design new points, lines and curves in the top 'design' layer.
The user can use the points, lines, and curves from the 'base' layer pattern in the formulas. (This may require a prefix to the 'base' layer objects to distinguish them from the new design points.)
The user saves the pattern which includes the 'base' layer pattern's formulas and arrangement.
Opening the saved pattern would show the arranged old pattern in the base layer and the new pattern in the design layer.
Original comment by Susan Spencer (Bitbucket: suzynumena, GitHub: Unknown):
This may be related to #335 "Add Multidocument Mode feature"
Requires implementing layers in Draw mode. Move and rotate pattern piece to a layer that can be displayed or hidden.
Related to #427 Save draft to an intermediate draft to hide previous steps