The function File - Import - Point Data' can be used to import geometric objects. These objects are represented by polygons and polygonal surfaces; you can even import volume grids using this format. It is not possible to import smooth surfaces (splines) using this formati, but you can spline the polygonal representations to achieve smooth curves and surface.

If you need to import higher order representations of surfaces and curves, it is better to use the more complicated and spaceous `IGES' format.

MegaCads-Format `Point Data'

The objects are defined by carthesic coordinates, which can get transformed to several transformations while reading the data. These transformations are performed in the following order:

1. Scaling of the coordinates in x-, y- und z-direction by the scale factors [Sx, Sy, Sz],
2. Rotation by an angle Wz around the point P0,
3. Rotation by an angle Wy around the point P0,
4. Rotation by an angle Wx around the point P0,
5. Translation of the coordinates in x-, y- und z-direction using the translation vector [Tx,Ty,Tz].

The input file is made up of the following structure:

• Header:
  • Number line containg the number NB of data blocks (objects) in the file.
• NB Data Block(s):
  • Header line containing scale and translation factors,
  • Number line containing the number(s) NI, NJ, and NK of coordinate points, [plus an optional switch NT,]
    • NI*NJ*NK coordinate lines (x y [z])
      The values for the z coordinate can be omitted; Megacads assumes a value of zero for the missing value.

Hints:

• For two dimensional objects (airfoil coordinates), set the coordinate counts for NJ and NK to 1,
• The optional switch NT can be set to 1 to perform a standard transformation (useful for fuselages and nacelles made up from sections). The transformation is a rotation of the section back into the x-y plane by setting y' = sqrt(y^2 + z^2) and z' = 0.0. y and z are the coordinates in the file, y' and z' are the transformed coordinates, as used by MegaCads.
• Comment lines can be inserted anywhere in the file, but not inside a block of coordinates. Comment lines start with a "#", a "%", or a "$" sign.

Example:

#
# Dataset including far field boundaries for the P3V9 nacelle.
# Datensatz mit den Fernfeldgrenzen für die P3V9 Triebwerksgondel
#
# Creator: Martin Hepperle 9/1994
# 
# Number of data sets in this file
# Zahl der Datensätze in dieser Datei
# |-----|
# |  N  |
# |-----|
     13
#  
# The following transformation parameters are valid for the next
# data set.
# Die folgenden Transformationsfaktoren gelten für den nächsten
# Datensatz.
#
# ---- Scaling -----------------------------------------------------
# ---- Skalieren ---------------------------------------------------
# Sx .... The scaling factors applied to the three axis directions
# Sy .
# Sz .... Die Skalierungsfaktoren für die drei Achsrichtungen
#
# ---- Translating -------------------------------------------------
# ---- Translatieren -----------------------------------------------
# Tx .... translation vector applied to the three axis directions
# Ty .
# Tz .... Translationsvektor für den Koordinatensatz
#
# ---- Rotating ----------------------------------------------------
# ---- Rotieren ----------------------------------------------------
# P0x ... pivot point for the rotation around the three axis directions
# P0y .
# P0z ... Drehpunkt für die Rotation um die drei Achsrichtungen
#
# Wx .... rotation angle for the rotation around the three axis directions
# Wy .
# Wz .... Drehwinkel für die Rotation um die drei Achsrichtungen
#
# |------------------------- Datensatz 1 ----------------------------|
# |  Sx    Sy    Sz | Tx   Ty   Tz  | P0x  P0y  P0z |   Wx   Wy   Wz |
# |-----------------|---------------|---------------|----------------|
  0.422 0.422 0.422   2.32 0.0  0.0    0.0  0.0  0.0    0.0  0.0  0.0
#
# number of points for this data set, i, j, k
# Punkteanzahl für den Koordinatensatz, i, j, k
# |-------------|
# |  I   J   K  |
# |-------------|
      21  1   1
# coordinates, no comments permitted inside the block !
# Koordinatenpunkte, innerhalb dieses Blocks sind keine Kommentare erlaubt !
   23500.    284.3     0.234
   23500.   1050.00    0.396
    ...       ...       ...
#
# ---------------------------- data set 2  ---------------------------------
# ---------------------------- Datensatz 2 ---------------------------------
# |------------------------- Datensatz 1 ----------------------------|
# |  Sx    Sy    Sz | Tx   Ty   Tz  | P0x  P0y  P0z |   Wx   Wy   Wz |
# |-----------------|---------------|---------------|----------------|
 0.0435 0.0435 0.0435  2.325 0.0 0.0   0.0  0.0  0.0    0.0  0.0  0.0
#
# no. of pts.  i, j, k
# |-------------|
# |  I   J   K  |
# |-------------|
      2   1   1
#
   23500.   1050.00      0.
   23500.   1650.00      0.
#
# ---------------------------- data set 3  ---------------------------------
# ---------------------------- Datensatz 3 ---------------------------------
#
    ...
# more data sets
# weitere Datensätze
#