#### 10.11.4 DrawFacet

• DrawFacet(facets1, [options1], facets2, [options2], ... )
• Description: that macro sorts all the facets and displays them with respect to their options with the possibility to smooth ( GOURAUD algorithm ) or not, but the eventual intersections are not handled. Possible options are:
• backculling := < 0/1 >. Shows if the non visible facets have to be eliminated or not (0 by default).
• color := < color >. setting the color (white by default).
• contrast := < positive number >. The ordinary contrast is $1$ (default value), a contrast set to zero means the color is solid. That number is used to vary the contrast between the facets of the same list.
• smooth := < 0/1 >. Shows if the GOURAUD algorithm (facets smoothing) has to be used or not in the pstricks or eps exports (0 by default).
• The default options are not reinitialized between <facets1> and <facets2> (idem for the following), then, by default, options of <facets2> and <facets1> are the same. If the options are identical, <facets1> can be replaced by <[facets1,facets2]>, or by an empty list ([]) for <options2>.
• If there is not smoothing at all, the macro DrawFlatFacet is a bit more accurate. If there are many smoothings (or only smoothings) to do on a great number of facets, the screen rendering can take time and the command draw("SmoothFacet",...) is then preferable, because the smoothing is only done at the export not at the execution.

 \begin{texgraph}[name=DrawFacet,                    export=eps]   Load("PolyedresII.mac"),   Marges(0,0,0,0),size(7.5),   background(full,beige),   DrawFacet(Sphere(M(0,0,3.5),1.5,30,15),                  [color:=steelblue,                   backculling:=1,smooth:=1],             Cube([0,0,vecK],M(1,1,0)),                  [color:=orange,smooth:=0],             Cube([0,0,vecK],M(2,2,-4)),                  [color:=gold]                  )   \end{texgraph}

DrawFacet