What is Alberti?

Alberti is a perspective layout drawing application, named after Leon Battista 
Alberti, who quantified modern perspective drawing in his treatise "Della 
Pittura". 

Why is it needed?

Undertaking a complex, accurate perspective drawing requires an enormous 
amount of physical space. Depending on the requirements of the drawing, a 
14x17 in. layout might require a drafting table 5 feet wide and 10 feet deep. 
On top of this, you would need a number of impractically large tools: a 
straight-edge, a drafting triangle, possibly a compass fashioned out of a peg 
and string.

In short, it makes perfect sense to do this in software.

Then why not use an existing solution like AutoCAD or 3ds Max? Because these 
tools are overkill. Alberti provides a highly streamlined interface tailored 
specifically to the requirements of rapid, natural perspective layout drawing. 
It is not a 3D modeling tool.

Features

At its most basic, Alberti provides an infinite, zoomable workspace, and two 
core tools: a line tool and an arc tool. With these tools and a knowledge of 
perspective, the basis of any conceivable form can be accurately constructed.

Natural extensions of these tools follow: perpendicular and parallel line 
tools. Automatic perspective space construction tools (in three-point, 
two-point, and one-point perspective flavors).

Alberti also allows the user to import images (such as scanned sketches) onto 
which a perspective space can be superimposed.