BYU (.byu)

Background

    • 3D geometry format.
    • Used for visualization of 3D polygonal meshes in CAD systems and other applications.
    • BYU is an acronym for Brigham Young University.
    • ASCII format.
    • Represents 3D objects as collections of polygon primitives.
    • Can store multiple 3D objects.

Import & Export

  • Import["file.byu"] imports a BYU file as a Graphics3D object.
  • Export["file.byu",expr] exports a Graphics3D expression to a BYU file.
  • Import["file.byu"] returns an expression of the form Graphics3D[GraphicsComplex[vertices,primitives,opts]].
  • Import["file.byu",elem] imports the specified element from a BYU file.
  • Import["file.byu",{elem,suba,subb,}] imports a subelement.
  • Import["file.byu",{{elem1,elem2,}}] imports multiple elements.
  • The import format can be specified with Import["file","BYU"] or Import["file",{"BYU",elem,}].
  • Export["file.byu",expr,elem] creates a BYU file by treating expr as specifying element elem.
  • Export["file.byu",{expr1,expr2,},{{elem1,elem2,}}] treats each expri as specifying the corresponding elemi.
  • Export["file.byu",expr,opt1->val1,] exports expr with the specified option elements taken to have the specified values.
  • Export["file.byu",{elem1->expr1,elem2->expr2,},"Rules"] uses rules to specify the elements to be exported.
  • See the reference pages for full general information on Import and Export.
  • ImportString and ExportString support the BYU format.

Import Elements

  • General Import elements:
  • "Elements"list of elements and options available in this file
    "Rules"full list of rules for each element and option
    "Options"list of rules for options, properties, and settings
  • Graphics elements:
  • "Graphics3D"BYU file represented as a Graphics3D object
    "GraphicsComplex"list of GraphicsComplex objects, each representing a 3D geometry stored in the file
  • Import and Export use the "Graphics3D" element by default for BYU files.
  • Data representation elements:
  • "PolygonData"the polygon data in indexed form
    "PolygonObjects"list of Polygon primitives given in absolute coordinates
    "VertexData"list of vertex coordinates
  • Import with a data representation element returns a list whose elements correspond to the geometry objects stored in the file.
  • Import["file.byu",{"PolygonData",n}] gives the polygon data of the n^(th) geometry object.

Options

  • General Import options:
  • BackgroundAutomaticwhat background color to use
    ImageSizeAutomaticoverall size of the graphics to display
    LightingAutomaticwhat simulated lighting to use in coloring 3D surfaces
  • All options of Graphics3D can be given when importing from BYU.
  • Advanced option:
  • "VerticalAxis"{0,0,1}orientation to assume for the coordinate system used in the file
  • By default, the Wolfram Language assumes that in the coordinate system used by the BYU format the vertical axis corresponds to the third coordinate.
  • With the setting "VerticalAxis"->{0,1,0}, the Wolfram Language will apply the transformation {x,y,z}->{x,-z,y} to all graphics coordinates when importing from BYU, and the inverse transformation when exporting to BYU.

Examples

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Basic Examples  (0)

Scope (3)

This imports a simple BYU file and renders it as 3D graphics:

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Import the GraphicsComplex object representing this sample file:

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Read the vertex coordinates:

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Import the corresponding polygon information:

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Convert the sample file to a list of Polygon primitives:

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Use ParametricPlot3D to create a 3D geometry:

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Export it to BYU:

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Export inline 3D graphics:

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Introduced in 2007
(6.0)