Analytical Drawing: Three Dimensional Form and Structure Applying Geometry to Forms Most objects can be deconstructed using the following five geometric solids.

Analytical drawing is a type of drawing that eliminates the appearance of flatness by describing the volume of an object. This sense of volume is achieved by defining the edges of the object from all sides. The best way to understanding the concept of analytical drawing is to compare the five objects below in a flat, two-dimensional rendering to the same five objects above rendered as geometric solids.

Three-dimensional Bounding Box The bounding box is a tool used to accurately render the three-dimensional form and structure of an object. The bounding box is an external structure that links, organizes and gives measure to various parts of an object, ordering formal and spatial relationships. Although the three-dimensional bounding box may look complicated, you only need two angles (the width and depth of an object) in order to build the entire bounding box. Using line weight on the edges that exist closest to the viewer will further enhance the sense of three- dimensional volume.

Relationship Angles To draw a relationship angle, close one eye, extend your arm out in front of you and allow your pencil to visually align and rests against the edge of an object. Keeping your arm locked, open both eyes and see what angle your pencil is making in space. Hold that angle and bring your pencil back to your paper. Use the angle of the pencil as a reference for the angle you are about to draw on your page. This process (often referred to as sighting techniques) is how you transfer information from subject to paper. In a three-dimensional bounding box, relationship angles allow you to establish the width and depth of your object, along with the plane they rest on. If either angle is drawn incorrectly the box will appear as if it is falling off a table or rotating in space. Relationship angles can also be used on objects that do not require a bounding box. In fact, they can be used on any object or multiple objects to establish a relationship between two points. In the example of the shoes, angles are used to establish the relationship between the tow and heel, the angle of the laces, the alignment of the boot holes, the opening of the boot from top to ankle and ankle to toe, they also allow the boot to accurately rest on a plane even though we can’t see a floor. In addition, even though the boot is a mix of geometric solids and organic forms, it is still rendered as an analytical drawing so that the sense of volume is retained.

Homework: Analytical Line Composition of a Still Life Complete on 18” x 24” charcoal paper using a graphite pencil. Create a still life of many dimensional objects that range in size and shape.

First determine the composition of your objects. Then reference the Analytical Drawing handout to walk through each step of the drawing process, i.e. (1) find the bounding box and center of your entire composition by measuring the highest and widest points, (2) placing your individual objects in a bounding box, (3) finding the angles that exist with your objects, and (4) drawing relationship angles from one object to another to establish the space (depth) between each object. Start your drawing with very light lines that allow you to work over any adjustments you make on proportion, scale, and angles without having to erase your lines. Do not erase; instead keep all the analytical lines in your drawing

Your pencil will double a tool for carrying out the sighting techniques learned in class (always find angles or measure with a straight arm and locked elbow). Make sure to draw the edges of your objects from all sides to retain the illusion of volume.

Remember: Consider the hierarchy of your line weight to show how objects and edges get lighter as they move away from you in space. Your subject cannot be centered on the page and your composition should engage all four sides of your paper.