Assignment 2

From the articles:

1. "Building 3D Worlds – 3D Geometric Graphics I" from The Computer in The Visual Arts by Anne Spalter, Addison Wesley Longman Inc. 1999, pp 212-253.

2. On Geometric Modeling: Excerpt from “Modeling”. Architecture’s New Media by Yehuda Kalay, The MIT Press, 2004, pp 141-147.


Both of the articles, "Building 3D Worlds – 3D Geometric Graphics I" and Geometric Modeling from “Modeling,” give a good overview of simple techniques used to make 3D objects on a digital modeling program. I am familiar with many of these techniques (primitives, sweeps, Booleans, etc) from working with various digital modeling programs.
The “primitives” technique is when you use simple shapes such as spheres, cones, cubes, and cylinders collectively to form objects. This technique, alone, may make the object look boxy and unrealistic. Curving the edges and combining other operations will help to make a more realistic model.

Sweeping is another operation that can be used. Sweeps is when you move one 2D shape along a line or rotate it about a point to form a 3D object. For example, a circle is swept across a straight line to form a cylinder. This can create more unusual or cured shapes than the primitives method. This may be a good technique to use in furniture design when modeling a curved arm of a chair.

Boolean operations can also be a great help when modeling more complex figures. They include union, intersection, and subtraction. Two 3D objects can be joined together or intersected and joined to form on object, or one object can be subtracted from another to create a void in that object. Subtraction is perfect for creating a void in a glass.

Digital clay modeling is done in various ways. This is when one segment or plane of an object is transformed to alter the shape of the entire object. For example, a point on a line can be pulled to create a bend in the line, or a plane can be rotated to create a twist in the object. Most complex objects will use this method and a variety of all methods.

I was also familiar with the terms wire frame, surface modeling, and solid modeling from the Geometric Modeling chapter. Wire frame objects are made up of only the edges of the shapes. They do not show the side planes of the object or any other detail. They are easy to work with and it does not take as much time for the computer to render these objects. However, it can be hard to tell where objects intersect and what the true form will look like. Surface models can help a person visualize the model more than wire frame. In surface models, the edges and surface planes are visible. This hides all of the lines that are within intersecting objects and can help define the shape of the combined object. However, surface modeling does not show color texture or shadows like solid modeling can. Solid modeling allows you to calculate the volume and surface area of the object.

While reading "Building 3D Worlds – 3D Geometric Graphics I," I have worked with and understood everything up until the section on Hierarchy. I am somewhat familiar with Hierarchy, but I myself have never worked with it in a modeling program. It is a simple concept to understand, where each component of an object belongs to a larger component. When you move a larger component, all of its parts move with it, but when you move a smaller component, its larger components do not move. This technique is best used in animation for movies or video games. I have not used this when modeling architectural objects. However, I have used grouping that allows me to move only the objects in one group as opposed to just one or all of the objects in the model.

The chapter on Algorithmic Form Generation in "Building 3D Worlds – 3D Geometric Graphics I" was new to me. It was not until the invention of fractals that it was possible to describe many forms in nature. With this, self-similar objects can be repeated to form an object such as branches repeating to form a tree. Graftals were also created to reproduce objects but in a more random way than with fractals. With this technology, growth simulations can be made to create more complex plants. These technologies are great for producing realistic scenes in movies or video games.

Overall, these two articles give a good overview of basic modeling tools and an introduction to 3D modeling. While most 3D modeling programs have some form of these tools, one must learn the different ways each program works and carries out different techniques. However, using a 3D modeling program for interior architecture can make designing much easier. It will be easier to alter designs, and also to visualize designs in a realistic setting. Different textures can be added to visualize a variety of options very easily through the computer. Clients can see what a design looks like and how it works without a physical model being made. Digital modeling also allows for the model to be in more than one place at a time.