Re: [Plib-users] BGL Loader

[John T. <ndc...@mx...>]

Steve Baker wrote:

> John Tsao wrote:
> >
> > Surprisingly to me, about 90% of the the polygons in BGL files (for urban areas)
> > are actually composed by  BGL_BUILDING.  The command takes 4 arguments of  the
> > dimension of the buildings (another 4 are typically just 0's)...
>
> Probably the origin of the building is three of those...dunno what the fourth would
> be.  Probably a rotation angle.
>
> > ...and simply draws blocks.
> > I need to think about how to embed this procedure into ssgLoaderMDL.
>
> Just make it generate an ssgVtxTable containing a cubeoid.
>
> You can hack the code to generate an arbitary cuboid from plib/src/ssgAux/ssgaShapes.cxx
> (ssgaCube::regenerate() is the function you need).  Please don't actually generate an
> ssgaCube object though (although that would *seem* reasonable) because it would create
> a dependance on libplibssgaux.a that would break the build mechanism for 90% of PLIB
> applications.
>

I have tried ssgVtxTable in tux_example. Looks Ok.  To be safe, I think I won't use
ssgaCube.
One little question: I know what a normal vector of a surface is. However, it looks like
every vertix can have it's own normal vector. I am confused.

John Tsao