Assignment #2

I think these two articles:  Geometric modeling and Building 3d worlds-3D geometric Graphics I, are very related with each other. They both provide a wide overview of different techniques to create 3D objects in a 3D computer program.

 The geometric modeling lecture deeply explain three general categories for representing geometric shapes:

Wire Frame Models: This is the simplest and oldest approach used to represent 3d forms. When we use a wire frame model we can only see the figure’s contours alone.

Surface Models: These models represent the vertices, edges, and faces of an object.

Solid Models: These are the most complete and well formed, they can support computation of intersection and difference of two objects.

Since I use AutoCAD as my main tool for modeling I’m very familiar with all these concepts.

I’ve also used the Constructive Solid Geometry representation whenever I need to model different parts of a building, like columns (cylinders), walls (blocks) combined through union, intersections and differences.

 On the other hand, the Building 3D Worlds-3D Geometric Graphics I lecture explains a detailed overview about 3D modeling and its advantages. During this reading I could recognize many of the concepts since I’ve used them to do 3D modeling work.

This lecture also accentuates the rendering method after the 3D modeling process is finished by first, creating simple model elements, assembling them into more complex objects, arranging objects in a 3D scene, choosing its materials, choosing its viewpoints and rendering methods.

At the same time I recognized different 3D tools such as Primitives and sweeping, which is like an extrusion tool: a 2D shape can be extrude in a straight line to become a 3D solid or it can be curved path around an axis to make a revolved form.

Boolean operation is also a tool that I’ve implemented. This approach has allowed me to make operations such as: union, difference and intersection on 3D objects. I could also recognize the Digital Clay and 3d Sculpting concepts. I few years ago I experienced using Maya Software; I particularly used it for character modeling. During this course I learned how to use splines curves and patches to create for example the face and body of a particular character. This option allows you to move each of the vertex that shape the patch in order to deform the surface and create a variety of contours. You can also increase or decrease the resolution of these patches, creating more vertexes and allowing the modeling process to be more accurate. At the same time we wanted to model the body of this character, the legs and arms were cylinders and later modeled into a more realistic manner. Hierarchy in 3D computer graphics, Joints and Slider were also very familiar to me. During the Maya course we used these tools to create for example the bones of the character. The hierarchy would organize the model components by their ability to control each other. This structure is also the basis for the Joints, which are the relationship among the model parts that determine precisely how one part can move relative to another. Figure 7.27 (page.237) explains the Slider tool (which is related to the Joints), which is able to move along one axis but not others. (For example: a wrist moving up and down).

Particle System is also a concept that I’ve worked with. These are self-similar forms and I was able to use this tool for creating samples of fire and explosions using the Maya Software.

Concepts such as Algorithmic Form Generation were new for me.

These kinds of 3d modeling tools are very effective and helpful at the time we seek to represent any interior space. We could model walls, stairs, furniture, and finally renderer it to obtain an outstanding representation of these future spaces. It is an excellent way to show our work either to clients or professors in a realistic manner.