Cleaning Up 2D Drawings Extracted from a 3D Model
Screenshot
	This workflow emphasizes how to use extracted line work from a 3D model in order to iterate and refine a design. Precision, accuracy and organization are also emphasized in using the line work to produce a final drawing set. Starting with an existing digital model, we will redesign and refine portions of a building. The use of layer management is critical in working efficiently.
Uses Tool(s)	AutoCAD 2012

This workflow concentrates on digital drawing techniques. A digital model has been Section ed, Split , and translated into line work by the Make2d command.

Steps

Organizing Drawings for Editing

As design students we often forget that digital models are primarily tools that we use to understand our designs, and that ultimately, our work will be described (and presented) within the confines of two-dimensions. Therefore, we should set some time aside for designing in 2D. After extracting plans and sections from a digital model it is important to take the time to review them.

For example, lets say that we want the westward facing windows to reflect the repetitive rhythm of the vertical mullions that recede along the south facade of the building.

Identifying design modifications

Before we can begin to redesign this aspect of the building, we will need to refer to our plans in order to understand how our proposed window adjustment will change the interior conditions of the design.

First, in order not to destroy our previous work, Copy the LONG SECTION, GROUND PLAN & 2ND FLR PLAN over. Rotate and align them accordingly. Using the Trim command, remove the line work that is representing the Split and removed portions of the digital model.

Plans rotated, aligned & trimmed

Construction Lines

Our redesign takes place on the ground floor. Using construction lines will be helpful in precisely viewing how our adjustments will alter the plan of the building.

For this workflow's sake, lets say that we want to experiment with using the dimensions of the narrow window as our standard window size to be equally distributed along the west facing wall.

Set up two new layers called "construction lines" and "window adjustment". Draw the new window, equally distribute it along the wall, and connect construction lines to the plan.

Construction lines - From section to plan

Redesigning

Now we can clearly identify where the added windows interfere with the interior wall partitions. Some adjustments will need to be made.

For example, some walls need to be cut in plan, others need to be moved a bit.

Wall to be moved

Using the Trim , Split , Extend & Move commands, redesign the west wall facade and interior. Don't forget to Copy glazing elements and position them into the newly cut openings.

Original versus redesigned west wall

Now we will have to honor the adjustments that we've made by including all newly revealed elevational information. Within our model two new interior surface corners are revealed as well as a continuation of the ramp. Draw construction lines extending from the plan in order to accurately position the new line work. Delete any newly obscured elevational information.

New elevational information revealed

Updating Master Drawings

Always remember to Copy any information that was modified and replace the old line work in the master drawings with it.

Assigning Line Weights

Cleaning up the line work is a critical step in generating legible drawings. If unfamiliar with this process, review this workflow: Cleaning Up Drawings in 2D Rhino + Illustrator

After cleaning up the drawings, we can begin to assign line weights depending on the distance that edges (lines) recede in space from the section cut plane. This operation is paramount in describing three-dimensional spatial relationships in two-dimensional representation (drawings).

Continuing with working on the Long Section, we can use the plans to determine how far our line work needs to appear to fall back into space. In order to stay consistent, create zones in plan that correspond to different line weights.

Connect the appropriate construction lines.

Line weight zone assignments + corresponding construction lines

Now, using the Properties panel, move the appropriate existing line work into their newly assigned line weight layers.

Repeat this step for the addition floor above.

Long section line weights assigned

Repeat the steps above for any remaining sections, plans & elevations.

Drawing set - Layers assigned