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05/02/2008, 14h47

On Feb 5, 2:08 pm, Richard Heathfield <r...@see.sig.invalid> wrote:
> johnnash said:
>
> > i am writing a scientific software in C language which will be use for
> > calculation of radar cross section of large aerospace/marine objects.
> > the technique i will be using is ray tracing. The aerospace/marine
> > objects will be modelled by using NURBS surfaces. So a cad file
> > containing these geometrical entities will be the input to my
> > software. My questions are
>
> > 1. how can i read such cad files in C language ?
>
> http://www.wotsit.org/list.asp?fc=19provides file format information for a
> variety of CAD formats.
>
>
>
> > 2. How do I process the NURBS surfaces ? I mean how should I create a
> > struct which will deal with each surface ?
>
> http://www.rw-designer.com/NURBSgives some basic information on NURBS
> curves. (Don't take that site as gospel, though - it may be that the
> graphics guys - see below - have better recommendations.)
>
> Since the number of splines in each curve is variable, I would recommend a
> dynamic structure. If you can pin down what information you need to store
> and what the variable parts are, we could certainly you to express
> that in C.
>
> > Please me or guide me to a ng where some graphics/c experts may
> > be able to .
>
> For the C bits, right here is fine, but first you need to establish exactly
> what you're trying to represent and manipulate, and the best place for
> that is probably the comp.graphics.algorithms newsgroup.
>
> --
> Richard Heathfield <http://www.cpax.org.uk>
> Email: -http://www. +rjh@
> Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
> "Usenet is a strange place" - dmr 29 July 1999

Hi Richard,

Thanks for the tutorial it was certainly ful. as far as the C bits
are concerned the only problem I seem to have is as to how I must go
about designing the program. I'm only a intermediate level programmer
and have only 5-6 months of time to finish this huge project(working
full time). So I was wondering as to how I must divide this program
into smaller modules i.e. all the .h files and .c files. Is there any
particular methodology that might in deciding how I must break
down the problem into smaller pieces ?
Do you know about some ray tracing codes ? Do you think it will
to go through some of these codes in order to get some idea as to how
I must begin coding ?

05/02/2008, 14h47	#5
johnnash Messages: n/a Hébergeur:	Re: need some On Feb 5, 2:08 pm, Richard Heathfield <r...@see.sig.invalid> wrote: > johnnash said: > > > i am writing a scientific software in C language which will be use for > > calculation of radar cross section of large aerospace/marine objects. > > the technique i will be using is ray tracing. The aerospace/marine > > objects will be modelled by using NURBS surfaces. So a cad file > > containing these geometrical entities will be the input to my > > software. My questions are > > > 1. how can i read such cad files in C language ? > > http://www.wotsit.org/list.asp?fc=19provides file format information for a > variety of CAD formats. > > > > > 2. How do I process the NURBS surfaces ? I mean how should I create a > > struct which will deal with each surface ? > > http://www.rw-designer.com/NURBSgives some basic information on NURBS > curves. (Don't take that site as gospel, though - it may be that the > graphics guys - see below - have better recommendations.) > > Since the number of splines in each curve is variable, I would recommend a > dynamic structure. If you can pin down what information you need to store > and what the variable parts are, we could certainly you to express > that in C. > > > Please me or guide me to a ng where some graphics/c experts may > > be able to . > > For the C bits, right here is fine, but first you need to establish exactly > what you're trying to represent and manipulate, and the best place for > that is probably the comp.graphics.algorithms newsgroup. > > -- > Richard Heathfield <http://www.cpax.org.uk> > Email: -http://www. +rjh@ > Google users: <http://www.cpax.org.uk/prg/writings/googly.php> > "Usenet is a strange place" - dmr 29 July 1999 Hi Richard, Thanks for the tutorial it was certainly ful. as far as the C bits are concerned the only problem I seem to have is as to how I must go about designing the program. I'm only a intermediate level programmer and have only 5-6 months of time to finish this huge project(working full time). So I was wondering as to how I must divide this program into smaller modules i.e. all the .h files and .c files. Is there any particular methodology that might in deciding how I must break down the problem into smaller pieces ? Do you know about some ray tracing codes ? Do you think it will to go through some of these codes in order to get some idea as to how I must begin coding ?