large points file - how to cut out a rectangle

I have a large (200mb) points file, from which I need to import just a
specific area into acad. Can this be done from the command line, or do
I need a separate, or add-in program?

 

Just curious - what does the 200Mb file represent? What type of work
do you do? I am told Terramodel handles large numbers of points much
better than ACAD but I have yet to see this theory proven.


Happy Trails To You

 

The file represents an area of sand dunes. I'm looking to cut out a
rectangular area and use acad to generate contours and experiment with
surface modeling/lighting. I just looked up Terramodel - too pricey, I
think.

 

HiHo;
Import the file into Excel or some data management program.
sort by X then Y. Import the XY range you are interested in
into AutoCad.

 

Can XL handle files this large?



Happy Trails To You

 

What Trimble does not tell you on their web site is that you buy the
FDM version of Terramodel from just about any Trimble dealer for $100
or so - I think the list is C$375 in Toronto. For another $100 you
can register it with Trimble for support by phone & email for a year,
so it's not as expensive as they'd have you believe.

The Field Data Module is the one they give away with the Sitevision
automatic grading systems, and you can do just about any dtm
preparation and points editing with it.

If you want to draw smoothened contours, or design roads or piping
systems, or manage a drawing/plotting system, or some of that
additional specialized stuff, then you're into the bigbucks versions.

If you are capable of doing some programming for simple processing of
ascii files why not process your file and throw away anything that is
outside a given rectangle, writing the ones inside to a new file, then
process that new file?


Happy Trails To You

 

Thanks for that. File opens OK in Excel - need to practice with sorting
and save formats.

 

Hey John,

I was looking yesterday for a text editor that could handle large
files so I could edit Autocad DXF files, and got a few good
suggestions.

I dl'd and tried one on the largish dxf I had, then remembered fooling
around with that zipped DAT file you sent me several weeks ago.

After loading it into the editor (EDITPAD.PRO) I was trying out, I
discovered that it after deleting the fuzz off the front of the file,
it actually has 606,759 points in it - not the 64k I/we thought
before.

I would guess that XL screwed up on that large a file and threw away
the extra (most) points.

I then imported the file into Terramodel and I'm looking now at a
(very) slowly revolving rendering of the whole darn thing. When it
finally gets through the stack of whatever the heck I asked it to do,
I'll render a smaller section of it and see what it actually looks
like up close.

I'm surprised that Tm didn't even hiccup over almost 2/3 million
points!

- Tom

Happy Trails To You