Navigating in 3D Max

1
Navigating in 3D Max

• V106.02 part A

2
Viewing Objects and/or Scenes

• Depending upon the software program, the image
  on the monitor could be a Perspective view, an
  orthographic view, or a combination.

3
Viewing Objects and/or Scenes

• 3D Studio Max, Rhinoceros, and some other
  modeling programs open with a four window display
  showing top, side, and perspective viewports.
• Maya opens with a single perspective view with
  orthographic views available on demand.
• Most programs allow you to fill your display area
  with any single viewport or varying multiple
  combinations of display windows.

4
Viewing Objects and/or Scenes

• Various veiwports may be formed by viewing
  angles.
• The image viewed depends upon the line of sight
  of the viewer.
• To move across a scene is called panning.
• The scene may be rotated about any of its three
  axes x, y, and, z.
• Views may be zoomed which magnifies the image.
  The size of the object is not increased.

5
Perspective

• Perspective mimics the way a human eye works and
  provides scenes that have a natural appearance.
  Perspective windows are included in all 3D
  modeling programs.

6
Perspective

• In perspective, parallel line converge at a
  vanishing point on the horizon. Perspective
  views typically contain one, two, three vanishing
  points. Horizons may be raised or lowered to
  change the vertical viewing angle.
• In perspective, objects seem to become smaller as
  they move away and larger as they come closer.

7
Perspective

• Objects seem to become dimmer as they move away.
  Atmospheric features in the software can be used
  to simulate atmospheric density.
• Perspective viewports can distort space and fool
  the eye when trying to position objects in 3D.
  It is not a good idea to attempt object placement
  and alignment using the perspective window alone.

8
Orthographic (Parallel Projection)

• Orthographic (Parallel Projection) viewports
  provide an image in which the line of sight is
  perpendicular to the picture plane.
• Ortho means straight. In orthographic
  projection the projectors extend straight off of
  the object, parallel to each other.
• Points on the objects edges are projected onto a
  picture plane where they form line on the plane.
  The lines create a 2D image of the 3D object
  being viewed.

9
Orthographic (Parallel Projection)

• Typically six different views can be produced by
  orthographic projection
• Top, bottom, front, back, left, and right sides.
• Lines and surfaces that are inclined to the
  picture plane appear as foreshortened edges and
  surfaces on the plane to which they are
  projected.
• Orthographic viewports are extremely useful in
  the accurate alignment and positioning of objects
  and features with respect to other features and
  objects .

10
Coordinate systems

• Coordinate systems are used to locate objects in
  3D space.
• Lines drawn perpendicular to each other for the
  purpose of measuring transformation are called
  the axes.
• In the 2D Cartesian coordinate system there is a
  horizontal axis called the X-axis and a vertical
  called the Y-axis.
• In 3D space a third axes is added called the
  Z-axis.

11
Coordinate systems

• Where axes intersect is called the origin. The
  coordinates of the origin are 0,0 on the 2D plane
  and 0,0,0 in 3D space.
• Numerical location placed uniformly along the
  axes are called the coordinates. These numbers
  identify locations in space. When written or
  displayed, numbers are always given in the order
  of X first, then Y, the Z.

12
Coordinate systems

• Axes may be rotated or oriented differently with
  in 3D space depending upon whether you are
  working with an individual object, a viewport, or
  objects within a scene.
• Local (user) coordinate system-assign axes to
  particular object.
• World (global) coordinate system-assign axes to
  the scene.

13
Coordinate systems

• Many 3D modeling programs allow you to constrain
  movement (rotation, scaling, and transformations)
  along one axis, tow axes, or three axes.
• For example, you could lock the X- and Y-axes
  thereby restricting movement of deformation to
  only a Z direction.
• Relative coordinates are used to transform an
  object starting at its current position.
• Absolute coordinates are used to transform an
  object relative to the origin.