In this assignment, we will construct a complete 3D model of CS 105 suitable for interactive visualization with a VRML 2.0 browser. The model should be complete (containing handrails, chairs, etc.), geometrically accurate (tolerance far less than 1 inch), and realistic-looking (with textures, etc.).

The goal of this assignment is to gain insight into traditional (interactive) 3D modeling methods. So, initially, please do NOT use procedural modeling methods (we will work on procedural methods for the rest of the semester). Instead, you should use an interactive 3D modeling tool. Cosmo Worlds (cosmoworlds), Autocad (acad), and possibly Alias (Alias), are available in Meca with on-line help.  You can use any information available to you to guide your interactive modeling, including measurements made with rulers, positions from floorplans, and images taken by cameras for textures. Autocad files for the CS building floorplans are available here. The DXF file (ascii version) for the first floor is here.

We have partitioned the modeling task into several ``pieces'' to be created by different groups of 2 or 3 people.
Pieces are assigned to groups on a first-come first-served basis.  The union of all these pieces should be a beautiful 3D model of CS 105:

• Group 1: Walls -
• Group 2: Floor & desks - rege, wtcorrea, and emilp
• Group 3: Ceiling - apleamon, eghchang, ianbuck
• Group 4: Handrails, chairs, and projector - gum, wxd, and wailee
• Group 5: All other objects (fire alarm, clock, etc.) - rjjensen, milliron, rodgers

Each piece of the model should adhere to agreed upon guidelines so that they all go together. We have agreed that the origin of the model is along the edge of the floor and the front wall at the center of the screen. The Y axis points up, and the Z axis points perpendicular to the front wall out into the room. One unit is one meter.
Here are other general guidelines to aid the modeling process ...

• Coordinate Systems:
  • Each object (e.g., chair) should be described in its own local right-handed coordinate system.
  • For each object, the Y axis should point up, and the Z axis should point out the ``front'' of the object.
  • Selection of the origin is very important to enable easy positioning and rotation with subsequent tranformations.  In general, the origin of each object should be the centroid of its base (i.e., the rotational center of the object in the plane on which the object rests).
  • Units are meters.
• Primitives:
  • Maintain as much semantic information in the model as possible
  • Use high-level primitives (e.g., spheres, cubes, cones, cylinders, etc), rather than unordered polygons
• Hierarchy - Group parts of objects according to these criteria, in order of importance:
  • First, by semantic function (so that actions can be associated with objects)
  • Second, by where they reside in space (think bounding box hierarchy)
  • Third, by other attributes
• Levels of Detail:
  • Create multiple levels of detail for complex objects and/or parts.
  • Create LODs for complex parts and well as whole objects
  • Each level of detail should be at least 2-4 times as simple as the next
  • The most detailed representation should have at most 1000 polygons
  • The least detailed representation should have at most 50 polygons
  • Many LODs can use textures to represent complex geometry (e.g., bookshelves, keyboards, window panes, etc).
• Other notes:
  • Describe logically different objects in different files, and use Inlines to combine them.
  • Use the DEF/USE instancing mechanism to place multiple instances of the same object.
  • Name semantically relevant nodes with vrml DEF statements even if they are not instanced again with a USE stmt.

We are working as an entire class on this project (the whole class gets the same grade).  So, please help each other as much as possible.  For instance, if you find a particularly effective way to perform a modeling task, please post a message to the news group so that others can benefit from your wisdom.  Likewise, if you get a digital camera to take pictures for textures, let others know so that you can both take pictures at the same time.

After we are done, we will produce renderings of our model and compare them to actual photographs taken from the ``same'' viewpoints in the real CS 105. The class grade will be affected by the similarity of these renderings and by the frame rate achieved during an interactive fly-through of the model using a VRML browser, like CosmoPlayer.
 

Related Links:

• VRML Repository
• SGI's VRML Site
• The Annotated VRML97 Reference Manual
• Alias/Wavefront
• Autocad