CAD file format specifications?

[Anthra Norell]

norseman wrote:
> Anthra Norell wrote:
>> Andres Acosta wrote:
>>> HI there Anthara have you checked out www.Blender.org, It is open 
>>> source and accepts a lot of your formats. for import and export.
>>> Anrdres
>>> Anthra Norell wrote:
>>>> Hi,
>>>>   Anyone working with CAD who knows about numeric data entry? I 
>>>> have 3d coordinates of a construction site on a slope (borders, 
>>>> setbacks and isometric elevation lines). Someone made me aware of 
>>>> Google's Sketch Up. It looks very attractive for the purpose of 
>>>> architectural planning, especially suited to create visual 
>>>> impressions. Doodling seems easy. But I have to start with modeling 
>>>> the terrain and the envelope and the only way to do that seems to 
>>>> be in one of several CAD file formats (skp, dwg, dxf, 3ds, ddf and 
>>>> dem). So I need to cast my numbers into one of these formats. Any 
>>>> suggestions?
>>>>
>>>> Thanks
>>>>
>>>> Frederic
>>>>
>>>
>>>
>> Andres,
>>
>>  Thanks for the tip. I wasn't aware of Blender. The web page looks 
>> promising. I downloaded it and am going to have a look at it.
>>
>> Frederic
>>
> ===================
> Frederic;
>         Could you be a little more specific about your data's current 
> format and the format that seems to best suit your needs?
>
> Tabular source data and dxf output files for use in CAD are quite 
> simple to write.  But this assumes dxf suits your display program's 
> needs.
>
> I think, for display purposes, Microsoft Word still accepts dxf files. 
> I run unix mostly and I don't keep up with Window$. ;(
>
>
> I suggest you Google for CAD (Computer Aided Drafting) programs. There 
> are free ones out there.  Most will take the DXF format.  If the 
> contours are pre-traced you can polyline them to make the contours 
> look correct. If the 3D points are X-section or random you will need a 
> contour generating program....  and so it goes.
>
> Let's start here - what is your area of expertise, how much math in 
> your background, why are you attempting this exercise?
>
> In order to communicate properly I need to know.  I can tailor my 
> comments to suit.
>
>
>
>
>
> Steve Turner
> Licensed Land Surveyor CA 5197 (inactive)
> 1st order Photogrammetric Compiler (2D depctions from 3D photo sets)
> in short  Map Maker, Master Grade
> norseman at hughes.net

Steve,
     Thank you  for your support. In a nutshell: I have a patch of 
constructible land and have the coordinates of its borders and a few 
other parameters. The patch is on a slope, so I had a surveyor do the 
isometric elevation lines. That's a lot more coordinates. The 
coordinates are plain text. Plain text is a breeze to convert into 
Python sequences. So I made a bitmap of the ground plan with the 
elevation lines as a template to play around doing architecture. A 
ground plan is 2d and as such is rather ill-suited to conceptualize the 
vertical dimension. Then someone made me aware of Google Sketch Up. It 
looks sort of like MS Paint in three dimensions: intuitive for doodling. 
Before I waste time doodling a flying or a subterranean house I want to 
make a three-dimensional template of the terrain and the constructible 
volume. The way to import numeric data, for what I see, is as one of the 
following CAD-file formats: skp, dwg, dxf, 3ds, ddf or dem. So I need to 
convert my coordinates into one of them, preferably the 
conversion-friendliest, but I don't have the specifications of any one.
     I had a look at Blender. It looks impressive too. It might be an 
alternative to Sketch Up. I'll worry about that later. My immediate need 
is a file conversion utility. A cursory inspection of Blender's menu 
tabs and the various help options didn't turn up a file-conversion 
utility. So, my question is: How do I convert a bunch of 
three-dimensional coordinates defining lines into a file format Sketch 
Up can read (skp, dwg, dxf, 3ds, ddf or dem)?

Frederic