doc-en/par-new-en.tex

   1 \section{Construction from scratch}
   2
   3 The object \Lkeyword{new} constructs a solid.  Two parameters are used: \Lkeyword{sommets}
   4 which indicates the list of coordinates of the different vertices, and \Lkeyword{faces} which
   5 gives the list of faces of the solid; a face is characterized by a list of the indices of its\Index{vertices}, listed
   6 in counterclockwise order
   7 when the face is viewed from the exterior of the solid.
   8
   9 \clearpage
  10
  11 \subsection{Example 1: a house}
  12 \begin{LTXexample}[width=6.5cm]
  13 \psset{unit=0.5}
  14 \psset{lightsrc=10 -20 50,viewpoint=50 -20 30 rtp2xyz,Decran=50}
  15 \begin{pspicture*}(-7,-4)(7,7)
  16 \psSolid[object=new,
  17   sommets=
  18     2  4  3   -2  4  3  -2 -4  3   2 -4  3
  19     2  4  0   -2  4  0  -2 -4  0   2 -4  0
  20    0  4  5   0 -4  5,
  21   faces={
  22   [0 1 2 3] [7 6 5 4] [0 3 7 4]
  23   [3 9 2]   [1 8 0]   [8 9 3 0]
  24   [9 8 1 2] [6 7 3 2] [2 1 5 6]},
  25   num=all,show=all,action=draw]
  26 \end{pspicture*}
  27 \end{LTXexample}
  28
  29 Note that the solid \Lkeyword{new} uses the same options as the other solids.
  30 For example, we give the same solid as above below, using the parameters
  31 \Lkeyword{hollow}, \Lkeyword{incolor}, \Lkeyword{fillcolor}, and \Lkeyword{rm}.
  32
  33 %% example 2
  34 \begin{LTXexample}[width=6.5cm]
  35 \psset{unit=0.5}
  36 \psset{lightsrc=10 -20 50,viewpoint=50 -20 30 rtp2xyz,Decran=50}
  37 \begin{pspicture*}(-7,-3.5)(7,7.5)
  38 \psSolid[object=new,fillcolor=red!50,incolor=yellow,
  39   action=draw**,hollow,rm=2,
  40   sommets=
  41    2  4  3  -2  4  3  -2 -4  3   2 -4  3
  42    2  4  0  -2  4  0  -2 -4  0   2 -4  0
  43    0  4  5   0 -4  5,
  44   faces={   [0 1 2 3][7 6 5 4][0 3 7 4]
  45    [3 9 2]  [1 8 0]  [8 9 3 0][9 8 1 2]
  46    [6 7 3 2][2 1 5 6]},
  47   num=all,show=all]
  48 \end{pspicture*}
  49 \end{LTXexample}
  50
  51 \subsection{Example 2: a \Index{hyperboloid} with a fixed radius}
  52
  53 %\psset{lightsrc=10 20 30,SphericalCoor=true,viewpoint=50 20 30}
  54 %\psset{SphericalCoor=true,viewpoint=50 20 30}
  55
  56
  57 As always, the options of the macro \Lcs{psSolid} can handle Postscript code, even \textit{jps code}
  58
  59 Unlike an example in pure PostScript, where we use the parameters
  60 $a$, $b$ and $h$ which are transmitted by the options of PSTricks.
  61 In this way one obtains a variable solid constructed from scratch.
  62
  63 Remark: the code being used comes from a \textit{jps} source used in practice, as in:
  64
  65 \noindent\url{http://melusine.eu.org/lab/bjps/solide/tour.jps}
  66 \begin{LTXexample}[width=6.5cm]
  67 \psset{unit=0.75}
  68 \psset{lightsrc=10 -20 50,viewpoint=50 -20 30 rtp2xyz,Decran=50}
  69 \begin{pspicture*}(-5,-5)(3,5)
  70 \psSolid[object=new,fillcolor=red!50,incolor=yellow,
  71   hollow, a=10, %% nb d'etages
  72   b=20, %% diviseur de 360, nb de meridiens
  73   h=8,  %% hauteur
  74   action=draw**,sommets=
  75    /z0 h neg 2 div def
  76    a -1 0 {
  77     /k exch def
  78     0 1 b 1 sub {
  79      /i exch def
  80      /r z0 h a div k mul add dup mul 4 div 1 add sqrt def
  81      360 b idiv i mul cos r mul 360 b idiv i mul sin r mul
  82      z0 h a div k mul add
  83     } for
  84    } for,
  85    faces={
  86     0 1 a 1 sub {
  87     /k exch def
  88     k b mul 1 add 1 k 1 add b mul 1 sub {
  89     /i exch def
  90     [i i 1 sub b i add 1 sub b i add]
  91    } for
  92    [k b mul k 1 add b mul 1 sub k 2 add b mul 1 sub k 1 add b mul]
  93   } for
  94 }]
  95 \end{pspicture*}
  96 \end{LTXexample}
  97
  98
  99
 100 \subsection{Example 3: importing external files}
 101
 102
 103 From a file describing a solid in a particular format (other than \texttt{\Index{.obj}} or \texttt{\Index{.off}}),
 104 we can create a \texttt{\Index{.dat}} file containing the coordinates of the vertices,
 105 and another \texttt{.dat} file containing the tables of indices of the vertices on each face.
 106 These files can then be entered as parameters \Lkeyword{sommets} and \Lkeyword{faces}
 107 when using the PostScript instruction \Lkeyword{run}.
 108
 109
 110 In the example below, the files \verb+sommets_nefer.dat+
 111 and \verb+faces_nefer.dat+ have been placed in the directory of the compiler.
 112
 113 \begin{LTXexample}[width=5.5cm]
 114 \psset{unit=0.4}
 115 \definecolor{AntiqueWhite}{rgb}{0.98,0.92,0.84}
 116 \begin{pspicture}(-7,-9)(7,7)
 117 \psset{lightsrc=30 -40 10}
 118 \psset{viewpoint=50 -50 20 rtp2xyz,Decran=50}
 119 \psset{RotX=90,sommets= (./sommets_nefer.dat) run}
 120 \psSolid[object=new,fillcolor=AntiqueWhite,linewidth=0.5\pslinewidth,
 121     faces={(./faces_nefer.dat) run}]%
 122 \psSolid[object=new,fillcolor=red,linewidth=0.5\pslinewidth,
 123     faces={(./faces_nefer_levres.dat) run}]%
 124 \psSolid[object=new,fillcolor=black,
 125     faces={(./faces_nefer_sourcils.dat) run}]%
 126 \end{pspicture}
 127 \hfill
 128 \begin{pspicture}(-7,-9)(7,7)
 129 \psset{lightsrc=-10 -40 -5,lightintensity=.5}
 130 \psset{viewpoint=50 -80 10 rtp2xyz,Decran=50}
 131 \psset{RotX=90,RotZ=30,sommets= (./sommets_nefer.dat) run}
 132 \psSolid[object=new,fillcolor=AntiqueWhite,linewidth=0.5\pslinewidth,
 133   grid,faces={(./faces_nefer.dat) run}]
 134 \psSolid[object=new,fillcolor=red,linewidth=0.5\pslinewidth,grid,
 135     faces={(./faces_nefer_levres.dat) run}]
 136 \psSolid[object=new,fillcolor=black,
 137     faces={(./faces_nefer_sourcils.dat) run}]
 138 \end{pspicture}
 139 \end{LTXexample}
 140
 141
 142 \endinput