3D Modeling

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3-D Modeling

• Designing in the world of 3-D

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Sources

• www.prodesktop.net
• http//www.3dcafe.com
• http//www.transvisioninc.com
• http//www.pixar.com
• http//www.tecso.com.pl/flash/flashindex.html

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3d Modeling

• Modeling in 3 dimensions is the future of
  computer design and animations. This technology
  has been available for many years, however due to
  the enormous costs to develop, this technology
  was out of affordability range for most
  companies.
• The uses for 3D design are almost limitless.

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Some Common Uses

• 3D development of landmarks even before they are
  constructed.
• Creating computer animated movies such as Pixars
  toy story.
• http//www.pixar.com/shorts/index.html
• Home builders can show a virtual reality tour of
  homes before they are built or can show buyers
  how their home looks with the custom options they
  choose.
• Automobile purchasers can see how their car looks
  with ther selection of colors, rims, accessories
  and additional options before they commit to
  purchasing their vehicle.
• Industry can utilize 3d modeling programs to show
  clients perspectives jobs before completion.
• http//www.tecso.com.pl/flash/flashindex.html

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3d Animation
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3-D Coordinate Space

• 3-D Coordinate Space
• Everything done in a 3d computer application
  revolves around the concept of a 3-d coordinate
  system.
• Imagine yourself (as difficult as it may be to
  do) at the very center of the universe. There are
  six directions ranged about you in three pairs
• Left and right--the horizontal or x directions.
  
• Up and down--the vertical or y directions.
• Forward and backwards or the z directions--for
  which we have no general name.
• Because of gravity, up and down have a physical
  meaning quite distinct from left and right or
  forward and backward, however we must try to
  throw away our concept of gravity for the use of
  3d modeling.

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Boolean Operations

• Boolean Operations are modeling methods that make
  use of two objects that overlap and therefore
  share part of the same space.
• In Boolean union, the geometry of the overlapping
  area is eliminated and a single object is created
  from the two using all of the exposed surface
  area. Union is generally used to merge objects
  that are most easily built from component parts
  that have been modeled separately.
• Boolean subtraction is used to sculpt out the
  overlapping volume from one object or the other.
  After the operation, one object is left, minus
  its overlapping region with the other object.
• Boolean intersection preserves the overlapping
  region only, eliminating all the rest of both
  objects.

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Boolean Operations Quiz
is each picture?
What type
of operation
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Results of Boolean Operations
Boolean Subtraction
Boolean Union
Boolean Intersection
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Model

• In the language of 3-D graphics, a model is a
  data file that contains the information needed to
  view or "render" a 3-D object. This information
  includes two types of information
• 1. The geometry--the shape--of the object.
• 2. The surface attributes of the object--meaning
  data that allows the object to be properly
  colored so that it looks like it is made of some
  kind of material (e.g. metal, glass, wood,
  plastic, etc.)

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2 Aspects of Modeling
Geometry
Surface Attributes Varnished Wood
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Primitive Solids

• Primitives are the basic 3D geometric shapes that
  are automatically generated by 3D modeling
  applications, and which therefore need not be
  constructed from scratch. A very considerable
  amount of modeling (perhaps most) begins with
  primitives, which are then edited and used with
  other primitives to create more complex objects.
• All applications provide spheres, cubes,
  cylinders (sometimes called disks) and cones.
  Some provide a wider array. All primitives have
  parameters that define their size and shape. A
  sphere necessarily has a center point and a
  radius, though the application may also provide
  for defining the sphere by its x,y and z
  extents--in effect defining the sphere by a cube
  into which the sphere will fit.

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Primitive Solids

• Cylinders Cubes Prisms/Cones

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Rendering

• Rendering is the process of producing images from
  a view of 3-D models in a 3-D scene. It is, in
  effect, "taking a picture" of the scene. An
  animation is a series of such renderings, each
  with the scene slightly changed.
• A camera is placed at a location in a 3-D
  coordinate space, pointing in a given direction.
  Those polygons that fall within the camera's
  field of view are mathematically projected onto a
  plane, just as a real camera projects an image
  onto film. The rendering process necessarily
  involves some means of determining whether a
  given surface of a model is obscured by another
  surface closer to the camera.

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Rendered Block
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Common 3d Modeling Commands Extrusion

• Extrusion is the process of creating
  three-dimensional geometry out of flat,
  two-dimensional shapes by drawing the 2-D shape
  along a path in 3-D space. The extrusion path may
  be a straight line or any kind of curve. If the
  path is linear, it may be normal to, or at any
  other angle to the extruded shape.

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Extrusion
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Revolve

• The Revolve command allows you to create a curved
  solid from a 2D object by sweeping it around an
  axis. Revolve can be used with an object made
  from Polygons, Circles, Ellipses, and Splines.
  Objects must have a closed path to be revolved.

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Revolve Command
Profile
Axis
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Loft Command

• The loft command allows you to create a solid
  object by extruding 2 or more shapes offset at a
  desired distance from each other. The shapes may
  be the same or different to use the loft command.

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Loft Examples
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Sweep Command

• A sketch is swept along a defined path to create
  a surface or solid. Some important
  considerations in sweeps include the relative
  location of the sketch to the sweep path and the
  curvature of the path. The sweep command can
  also be used to create a helix or a spring type
  object.

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Sweep Examples
Path
Profile