Drawing Classification Systems (Part-1)

Design drawings enables the professionals designers to visualize and communicate the features of a three-dimensional object or interior space.Then,detailed construction drawings are made to accurately describe what materials are to be used and how the object or space is to be constructed.The design drawing can be a three-dimensional pictorial sketch that shows what the object looks like in reality,or a series of related yet different views of the objects,such as a plan or top view and an elevation,as illustrated in figure.The first approach,the single view,attempts to portray the object as the eye would see it.The second approach,the multiview, relies on the eye to view a series of images and the mind to then put these views together into a whole.For example, a floor plan shows width and length of objects within a space.An elevation view is then drawn to illustrated height,but no third dimension or true depth is visually indicated.Classifies the various drawing systems according to these two broad categories.Many computer software programs now can produce some very convincing single-view drawings from multiviews, then allow designers to quickly flip back and forth between these two types of drawings.

Multiview Drawings:-

Multiview drawings can be visualized by what is commonly called the glass box theory.In this process,a three-dimensional object is imagined to be surrounded by a clear glass box.If the viewer looks along the perpendicular through any plane on the glass box.The object can be imagined to be a flat,two-dimensional image on that particular glass pane.The object can be viewed from above ( called a plan view) or the side (called an elevation view.) In turn,if these image are drawn separately, the viewer reverses the process and projects (by imagining) the multiviews onto a whole three-dimensional object.

Orthographic Projections:-

The word orthographic refers to the projection system that is used to derive multiview drawings based on the glass box model.Drawings that appear on a surface are the view a person sees on the trans-parent viewing plane that is positioned perpendicular to the viewer's line of sight and the object.In the orthographic system, the object is placed in a series of positions (plan or elevation ) relative to the viewing plane.

The most common types of orthographic drawings are the plan,elevation,and section.However no single one of these drawings can communicate the actual configuration of a three-dimensional object or space.They must be used together to accurately depict spatial and solid elements.In fact, more complex objects and spaces will require several more of each of these drawings. Multiview drawings lack the pictorial effect of perspectives (which are a type of single-view drawing),yet are more accurate for conveying correctly scaled objects,scaled objects,interiors,and buildings.

Single-view-Drawings:-

Single-view drawings attempt to picture an object or space as we normally see it in reality with all three dimension appearing simultaneously.They present relationships of objects.Space and materials in a realistic or photographic - looking manner.Single-view drawings can be either para line or perspective views.In para line or perspective views.In para line drawings lines are drawn parallel to one another and object features retain this relationship as they appear to record in the distance.This parallel phenomenon is what gives this drawing system the name praline.

The perspective view produces a more realistic picture,as it attempts to duplicate the way our eyes actually see objects and space.In perspective drawings,parallel lines in space or an object appear to converge to common distant vanishing point,as illustrated.Perspective drawings resemble a photograph and are the most convincing of the drawing systems.They generally take more time to produce by hand,but computer generation has made the process less time-consuming.

A) RECEPTION DESK SECTION:-

Paralines are usually faster and easier to develop than perspectives, as receding horizontal lines can be drawn with instruments,without calculating depths or drawing lines to a common vanishing point as is necessary in perspective drawings.However,when using computer-aided design (CAD),the speed of the rendering programs will govern which of these is produced the quickest. Paraline drawings are categorized according to the projection method used to develop them,and can be subdivided into two distinct types,axonometric and oblique.

Axonometric Projection:-

Some interior-designer refers to all pralines as axonometrics; how-ever,axonometric drawings are technically just one form of paraline drawing. Axonometric means "measurable along the axes."Axonometric drawings include three axes that relate to width,depth,and height.Each line drawn parallel to these axes is drawn at an exact scale.with the true length of the object depicted.The axonometric,diametric,and trimetric.These views are distinguished by the degree of variation visible of the principal faces of the object.In the isometric view,all faces represent true scales.The letter two systems show one or more faces in a reduced scale.

Isometric (derived from the Greek words meaning"equal measure") drawings presents the three primary faces of an object equaly and at the same angle with the viewing plane.The planes of width and depth are drawn at 30 degrees and the height is held vertical.Dimensions are scaled equally along all three axes.Isometric drawings are the easiest of the axonometric systems.To construct,but the visual distortion caused by parallel lines not appearing to converage to a distant vanishing point gives them a distinctly pictorial effect.Computer software now allows the designer to programme in dimensions for width,height,and depth.Then,isometric"wire frames."that show the construction lines can be quickly generated on the screen,as illustrated.Hidden or unwanted lines can also be easily turned off or removed from the image.

In dimetric and trimetric drawings,all principal faces are not held at equal angles to the picture plane.The dimetric drawing makes two faces equally visible and shorteness the third face.The trimetric rotates an object so that all three faces are at different angles to the picture plane.

In both dimetric and trimetric drawings,the scale along one or more of the principal faces is reduced proportionately to emphasize or deemphasize a features of the object.Both dimetric and trimetric drawings are more time -consuming to construct then isometric drawings,but have the advantage of presenting an object's best features and more closely resembling perspective drawings.