3D Space

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3D Space

• Authoring Interactivity 2

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3D Coordinates

• We will look at
• Coordinate systems
• Units and scale
• Axes
• Transforms
• Transform Properties

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3D Coordinates

• Coordinate systems
• 2d representations of points on a plane require 2
  coordinates
• x and y, e.g. (3.0, 2.1)
• Requires knowledge of units of scale

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3D Coordinates

• Coordinate systems
• 3d representations of points on a plane require 3
  coordinates
• x and y, e.g. (1.0, 0.5) representing
  horizontal axes
• z representing a vertical axis, e.g. - (1.0, 0.5,
  3.0)

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3D Coordinates

• Coordinate systems
• These coordinates are vectors
• Require an understanding of
• direction
• as well as the number of units

In this example, the z value will be
negative (1.0, 0.5, -3.0) Often denoted
as Vector(1.0, 0.5, -3.0)
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3D Coordinates
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3D Coordinates
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3D Coordinates
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3D Coordinates
So, this cube is 10 in x 10 in x 10 in
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3D Coordinates
Can change default units Under Customize
menu Units Setup
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Units

• Size of 3D objects will become very important
  when we apply physics later on
• Physics engine attempts to replicate real world
• So an object 1000m x 1000m x 1000m will behave
  differently to an object 1m x 1m x 1m
• Will need more force to move larger objects
• Pay attention to object sizes when creating in max

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Coordinate systems - Axes

• Objects positions and rotations in 3d space can
  be defined with
• Reference to their own coordinates
• These are local coordinates
• Reference to their parents coordinates (parents
  are objects that other objects are related to in
  a hierarchical manner) an earth object is the
  parent of a moon object
• These are parent coordinates
• Reference to the worlds coordinates
• These are world coordinates
• Where no hierarchical relationship exists between
  objects, the world is also the parent

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Coordinate systems - Axes

• Axes act as a visual representation of these
  coordinate systems.

In this example we can see the local axes of each
object showing their various Rotations The world
axes shown in the bottom left corner remains
unchanged
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Coordinate systems - Axes

• It is important to know the orientation of these
  local axes as they will effect how the object
  moves when scripted

Director example
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Coordinate systems - Axes

• It is often a good idea to reorient the axes of
  objects you have rotated in max to the world axes
  before exporting the world.
• This reorientation makes the response of objects
  to scripted movement more predictable.

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Coordinate systems - Axes
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Transformations

• Transformations are changes to 3d objects in the
  world space
• These transformations include
• Scale
• Rotation
• Position
• Transforms are the values of the transformations
• Transforms are shown in just under the timeline

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Transformations
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Transformations

• To transform an object with script
• We identify the world
• We identify the object within the world
• We access the transform property
• We state what type of transformation scale,
  position or rotation
• We assign a new value to the transforms as a
  vector
• member(3dWorld).model(smallBox).transform.posi
  tionvector(0,0,45)

Director example