Computer Modelmaking 101
PART 2 Computer-Generated Ruins and Antiqued Surfaces


Illusion is the basis for all scenographic art. Although theatrical performance is not dependent on having explicit images to support what playwrights include in their text, theater practice of the past four hundred years has made pictorialization a part of the theatrical experience. Despite Shakespeare's fervent plea to his audience that, "on your imaginary forces work," scenery has become an integral part of theatrical thinking and practice.

At first, scenic production was almost exclusively a painter's art; settings of the Restoration Theater, the period that marks the beginning of modern scenic practice, consisted primarily of large flat images against which performers were viewed. Actors, dancers, and singers had little direct involvement with three-dimensional scenic units; stages were usually raked planes to facilitate the viewing of audiences seated on flat auditorium floors. Platforms and stepped units were little used until late in the nineteenth century and coincided with an increasing invasion of the performer's space of three-dimensional scenic units that formerly were only large painted images at the rear of playing areas. The ballet is the only form of theater still primarily based on this early style of scenic production.

When popular theatrical tastes shifted from live stage performances to cinema, and later to television, audiences demanded ever-more "real" pictures to accompany the stories presented. Film media was almost from the beginning a form that required artists to create an illusion of reality from the playwright's written directions.

The advent of the computer, and its present-day inclusion in scenographic practice, has done nothing more than give scenographic artists newer and quicker ways to externalize those worlds embedded in a writer's text.

Oddly enough, the techniques used in computer-generated scenographic imagery is basically similar to late-nineteenth century and twentieth century scenic-building practice which uses framed forms onto which various kinds of flexible skins (canvas, muslin, wire cloth, etc.) are stretched. These covered forms are then textured and painted to create patinas of age or the effects of use. The under-structures are usually the simplest volume to which the form being created can be reduced. The modern computer modeler's task is little different from that undertaken by most scenic builders of the past century. Basically, the steps taken to create three-dimensional forms on the computer mirror those used in real-world scenic building.

A Note on Image Sources

Before beginning the main exercise, let us review some things most working scenographers know well: the manner by which scenographic designs evolve. The first two steps in the process are required no matter what kind of design is undertaken or what media or technique of fabrication is employed:

1. Conceptual Planning: This phase, it should be expected, is accomplished through the interaction of many people; directors, costumers, lighting designers, technical staff, etc.

2. Research Gathering, Sorting, Scanning, Selecting: This phase requires of the scenographer to take into consideration the wishes, restrictions, and constraints of the production as defined by those listed above, and to begin the culling of ideas and materials into a workable plan. These functions have not greatly changed over the past century. When the computer came into the design process, however, many ways scenographers went about their craft changed significantly.

An example as to how research gathering changed since the advent of the Internet is that many of the visual materials once gathered from libraries or from personal visual image resources can now be acquired from on-line image databases.

For instance, if I decided to use an image like that shown in figure 1, a Greek sculptural form known as a Caryatid, as the basis for a computer-generated three-dimensional object, I would first have to locate it, and then find the means to put it into my computer (usually by scanner).

Fig. 1 Caryatid from ArtToday Image Database

By using an Internet image service such as Zedcor's ArtToday, the actual source of figure 1, I have access to over 500,000 images from which to choose. Although this is a commercial service, the present yearly rate is only $70; for working scenographers or for theater design departments in colleges or universities, this cost is quite reasonable considering the ease with which imagery is accessed. Moreover, in the near future Zedcor plans to increase their archive to over 1,000,000 images that includes many Dover books, which are important resources for many scenographers. Figure 2 shows the Search Window of this database.

Fig. 2 ArtToday Image Database Search Window

Using the small window at the left of the screen, I am able to search for any images related to the name Caryatid. A hundred images were found in a matter of 5 seconds that were shown in small image formats nine or ten images at a time. When a particular image is deemed suitable, it can be downloaded onto the Desktop.

Creating Objects with Antiqued Appearances

The steps for creating objects and attaching bit-mapped surfaces to them was taken up in Modelmaking 101, Part 1. Here we only add some new information to the process and narrow the focus of our technique. Perhaps the most important point to be made here is that complex three-dimensional objects are less efficient to model and to render than are simpler ones.

Almost any shape, for that matter, can be made into a three-dimensional object using one of several options. For our purposes, however, I will only discuss three: lathed forms, extruded forms, and two-dimensional shapes.

Figure 3 shows a lathed half profile for the form created below.

Fig. 3 Strata 2-D Half Profile from Pasted Outline of Caryatid

This profile was based on the general outline of the image of the Caryatid shown in image 4-A, which was copied while still in the image-editing program Adobe Photoshop. There this silhouette shown in figure 4-B was created using tools of that program.

Fig. 4 Photoshop Outline Form for Lathed Object Profile

Once created, it was copied to the Clipboard and pasted into Strata Studio Pro as shown in Modelmaking 101, Part 1. This image was only used as a pattern for making the simpler half profile shape shown in figure 3.

Bump Maps Versus Vertices

Sophisticated as human vision is, the single eye is easily deceived. And it is monocular vision, which is most often the case in images captured by film media and that perceived on the computer screen, that allows the brain to be tricked into seeing a third dimension to objects when only two are present.

Computer three-dimensional objects do occupy a kind of space analogous to that of our common real-world kind. Computer three-dimensional objects can also have raised points, indentations, and angled surface planes just as actual objects do. But it is also possible to give three-dimensional object surfaces, such as that shown in figure 5-A, a variation of form and texture that they don't really have and in so doing give the illusion to a viewer that they are more complex than they are (fig. 5-B).


Fig. 5 Lathed Object Wireframe Mode and Mapped Image Rendering

These surfaces, moreover, respond to computer light sources in much the same way that their real-world counterparts do. The mechanism for these trompe d'oeil effects (a French term that simply means "deceive the eye," lies in the use of bump maps, a term that has a particular meaning in computer graphics. But just what is a bump map?

A bump map is a computer field that creates a image that seems to have uneven surfaces or textures despite the fact that the object is still one composed of smooth planes. The bump map fools the rendering engine into thinking that an object has an irregular surface when it is still relatively smooth. What makes this deception possible is that the rendering is interpreting white and dark areas mapped to the objects as actual raised or depressed areas. It is not possible here to go into the entire explanation as to how this process works; I strongly recommend that anyone who uses the computer for scenographic modelmaking that they study this subject since knowing how bump map files are created will not only improve their general modelmaking skills but will also significantly speed the rendering times of their models. To see how effective bit-mapped images can be when applied to simple forms like that shown in 5-A, study figure 5-B, an object created for the designs in this section as it is seen in ambient light (or to use Strata's term Global light). Then see how this same object responds to the placement of lights from various positions. Although the object itself is still a smooth lathed one, the white areas of the bump map respond as if they are raised areas reflecting the angle and color of lighting instruments in an actual theater.

Figure 6-B shows a Strata Studio Pro Spotlight focused at approximately 45° in plan and elevation to the object.

Fig 6-C shows the light with a changed color and shifted 180° in plan and elevation to the object. Figure 6-D shows the light with yet another color and shifted to the left side of the object in the same plane as the object.


Three-Dimensional Scenic Units and Set Properties Storage Rooms

There are very few working scenographers who do not recycle concepts and scenic forms into more than one design. On the computer, often it takes a great deal of time and tinkering to create a complex object for a particular project such as the one shown above. Once made, however, a few simple steps makes this object available for future designs.

In real-world theater, often elaborate objects built for one production are saved for future use by storing them in special spaces set apart from the main theater. The scenographer using the computer to model settings has much the same option. In Strata Vision 3d and Strata Studio Pro, objects built for one model can be saved as special files called Shapes and kept in libraries that are analogous to the storage rooms theaters maintain.

Not only can single objects be saved as Shapes and used in future models, but composite Shapes, that is, a Shape composed of one or more objects, can also be kept in the computer storeroom.

Figure 7 shows a unit of three Caryatid forms combined with a base wall unit and a top wall unit saved as a single Shape in its pre-rendered form.

Fig. 7 Wireframe Mode of Shape from Scenic Objects Library

Figure 8 shows an elevation view of the same unit.

Fig. 8 Rendered View of Shape from Scenic Objects Library

Figure 9 shows the completed model. The floor is also a Shape that is saved in a Scenic Objects Library. Any kind of object that might be useful in the future can be turned into a Shape and stored. For the program to be able to find these Shapes, however, they must be placed in the Shapes Folder of the main Strata Studio Pro or Vision 3d folder.

Fig. 9 Library Shapes used in Setting

Loading In Objects from Computer Storerooms

These are some steps needed to bring in an object to a current model.

1. When objects are used in a template model, they should not be brought into the model directly by dragging and clicking from the Shapes pallet, but should, rather, be placed into the model using the Insert Object command found in the Modeling Menu. The steps used for this procedure are as follows:

A. Go to the Shapes Menu and select Insert Shape.

B. If the Shape required is in the Shapes Library but not on the Shapes pallet bar, it is necessary to Load the Shape. This is done by clicking on the Load Shape option in the Shapes Menu shown in figure 10.

Fig. 10 Load Shapes Option

C. Pressing down on the Insert Shape bar shows the Shapes that can be inserted into the model as shown in figure 11.

Fig. 11 Insert Shapes Option

D. Click the mouse on the object name and an icon like that seen in figure 12-A appears in the modeling space. Hold down the Shift key to constrain the objects shape and drag the icon down toward figure 12-B. The object (fig. 12-C) in inserted into the modeling space. The size of the objects is determined by when the drag of the mouse is terminated. Holding down the Shift key insures that the object is correspondingly proportional to the original object and not distorted.

Fig.12 Insert Shape

Figure 13 shows the loaded Shape as it appears in the rendered model.

Fig. 13 Rendered View of Loaded Shape

Modifying Textures for Specific Projects

One of the good things about bit-mapped or paint images is that, using image-editing tools and filters of programs such as Photoshop, textures can be customized to fit specific projects. Although I have a number of brick-patterns in the Textures folder of Strata Studio Pro, none seemed exactly what I had in mind. The nearest was a pattern I had created using the shareware Photoshop filter named SF Mr.Sa^Kan-1.01, one of a set of filters included in a small collection called SuckingFish Filters. The original pattern I created is shown in figure 14.

Fig. 14 Original Brick Pattern

Using this file as a starting point, I was then able to weather and color the brick nearer to the tonality I imagined for the building walls of the model for a scene from West Side Story. The new brick pattern is shown in figure 15.

Fig. 15 Weathered and Colored Brick Pattern

This brick pattern was then applied to both the walls and to the street of the model as shown in figure 16.

Fig. 16 Balcony Scene - West Side Story

From even this brief discussion of ruins and antiqued surfaces, it is easy to see that by using relatively easy techniques in conjunction with low-resolution bit-mapped graphic images computer scenographic modelers can create complex scenes that even Piranesi might feel at home in.

And if you don't know who Piranesi is, here is an image of his from the ArtToday image database, the place from where we started.

Fig. 17 Piranesi Print: View of Antique Rome

Could this image serve as the basis for a computer scenographic model? No doubt about it. What you do on the computer is directly related to the tasks you put to it.

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