What did computer design replace? what were the two disadvantages to the past method(s) used by architects and draftsmen?

A. basically the plan drawings, then much more

B. harder to edit, unable to view in 3D

Explanation:

A. What did the computer design replace?

At the base, the Computer Aided Design (CAD) tools were created to replace the paper plans handmade by architects, draftsmen and other specialists/engineers who are creating structures on paper.

Over time, they added many functions like 3D viewing to be able to view the object design from various angles.

For buildings specifically, CAD can also include calculations of the materials needed (in terms of quantities and costs), resistance simulations to earthquakes and winds for example and so much more.  Saving lots of work and calculations.

B. What were the two disadvantages to the past method(s) used by architects and draftsmen?

The main disadvantage of paper plans and other pre-CAD methods was the difficulty to make changes.   For example, an architect designs a house for a couple, then the couple wants to have a bigger living room.  In the old days, a lot of work would have to be redone from scratch.  Now, a simple move of the mouse and all plans are adapted to the new specifications.

On paper-plans, it was impossible to have a 3-D image of the building or object.  So, they had to make multiple plans representing various angles/views of the object to provide a better understanding of the object.

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