-stlfile: CAD import via STL-file

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-stlfile: CAD import via STL-file

This section is for importing a geometry description from a CAD system^1.2 via a STL-file (STereo-Lithography). A STL-file describes a closed body via a set of triangles.

The so described body can be rotated, shrunk or expanded and shifted.

 ##############################################################################
 # Flags: nomenu, noprompt, nomessage,                                        #
 ##############################################################################
 # section -stlfile                                                           #
 ##############################################################################
 # file= /usr/local/gd1/examples/woman.stl                                    #
 # material  =  1                                                             #
 # whichcells= all, taboo= none, nboundaries=  1                              #
 # originprime    = ( 0.0, 0.0, 0.0 )                                         #
 # xprimedirection= ( 1.0, 0.0, 0.0 )                                         #
 # yprimedirection= ( 0.0, 1.0, 0.0 )                                         #
 # xscale = 1.0                                                               #
 # yscale = 1.0                                                               #
 # zscale = 1.0                                                               #
 # debend = no                          -- debend description around uaxis    #
 #    uaxis= z                          -- [xyz] : direction of debend-axis   #
 #    radius= 0.0                                                             #
 #    v0    = 0.0                       -- v0,w0: coordinates of the axis.    #
 #    w0    = 0.0                                                             #
 # show   = no                          -- ( yes | no )                       #
 ##############################################################################
 # doit, return, help                                                         #
 ##############################################################################

file= NAME_OF_STLFILE:
The name of the STL-File (in ASCII) that shall be imported.
material= MAT:
The material index that will be assigned to cells inside the volume.
whichcells
Possible values are all, or a material-index.
If whichcells=all, all volume inside the stl-body is assigned the material-index, provided the former material is not taboo. If whichcells is a material-index, only the parts of the stl-body that are currently filled with the given index are assigned the new material-index.
taboo
Possible values are none, or a material-index.
If taboo=none, all volume inside the stl-body is assigned the material-index. If taboo is a material-index, only the parts of the stl-body that are currently filled with another index than the given index are assigned the new material-index.
originprime= (X0, Y0, Z0):
xprimedirection= (XXN, XYN, XZN):
yprimedirection= (YXN, YYN, YZN):
xscale= XS, yscale= YS, zscale= ZS:
The coordinates of the STL-Data are transformed as follows: A 3x3 matrix (A) is built, such that A11, A21, A31 are the components of the normalized "xprimedirection". The direction "yprimedirection" is enforced to be perpendicular to "xprimedirection". The result is normalized and taken as the second column of (A). The third column of (A) is the normalized cross product of "xprimedirection" and "yprimedirection". (The matrix (A) is a rotation matrix.)
The coordinates of a point P of the STL-set are now transformed via
```
 
            P <= (A) * P
            P_x <= P_x * xscale + X0
            P_y <= P_y * yscale + Y0
            P_z <= P_z * zscale + Z0
```
show= [yes|no] :
Flag, specifying whether a plot of the transformed triangles shall be shown.
doit:
Puts the current data as the data of a stl-set into the meshing database.

Example

 # /usr/local/gd1/examples-from-the-manual/stl-example.gdf

 -mesh
    volume= ( -0.4,0.4, -0.4,0.4, -0.4,0.35 )
    spacing= 0.5/70

 -stlfile
    material= 34
    file= /usr/local/gd1/examples/brain.stl
 define(SCALE, 0.1)
       xscale= SCALE, yscale= SCALE, zscale= SCALE
       origin= ( 0, 0, -2.2 )
       xprimedirection= ( 1, 1, 0 ), yprimedirection= ( 0, 0, 1 )
    doit

 -volumeplot
    scale= 3
    doit

**Figure 1.13:** A discretisation of a brain, imported as a STL-file.
$\begin{figure}\centerline{ \psfig{figure=stl-example.ps,width=18cm,bbllx=-2pt,bblly=-2pt,bburx=760pt,bbury=552pt,clip=} }\end{figure}$

Example

 # /usr/local/gd1/examples-from-the-manual/stl-example2.gdf

 -mesh
     spacing= 2.2
 perfectmesh= yes
     volume= ( 0,200, 0,130, -200,0 )

 -stlfile
     file= /usr/local/gd1/examples/wagner60kASTL.stl
     xprime= ( 1, 0, 0 )
     yprime= ( 0, 0, -1 )
     material= 1, taboo= none
     show= yes,
     doit

 -volumeplot, scale= 2.5, eyepos= ( 1, 2, 0.5), doit

**Figure 1.14:** A discretisation of a Wagner bust, described as a STL-file.
$\begin{figure}\centerline{ \psfig{figure=stl-example2.ps,width=18cm,bbllx=-2pt,bblly=-2pt,bburx=760pt,bbury=552pt,clip=} }\end{figure}$

Footnotes

... system ^1.2: AutoCAD can export its data as a STL-file. The command is 'stlout'.

Next: -geofunction: Analytic description Up: Geometric primitives Previous: -gbor: A general body Contents