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    Reply
    *stac.at.techgrafx

    Re: Import CAD

    02-21-2010 07:19 AM in reply to: RBartsch
    I'm not buying into your delusions. You assume that no one use the OSNAP feature in AutoCAD and
    will draw lines and place objects in some willy-nilly fashion. I doubt your full understanding
    of AutoCAD and it's capabilities.



    STAC


    wrote in message news:6341034@discussion.autodesk.com...
    "incredibly inefficient"?

    maybe somebody should actually try bringing
    a DWG detail into revit as an image for tracing
    and see how easy it is- vs. muddying-up the
    project file with DWG data..

    and why would revit want to use those sloppy old
    hand drawn lines from AutoCAD exactly the way
    they are anyway?

    people are just not thinking- they never do..

    see the image..
    Please use plain text.
    *Expert Elite*
    Alfredo_Medina
    Posts: 2,258
    Registered: ‎06-11-2009

    Re: Import CAD

    02-21-2010 07:42 AM in reply to: RBartsch
    Facts, not biased opinions, about the image you posted:

    1. The drawing on the left is not a group of 'sloppy hand drawn lines from AutoCAD' as you said. It's not drawn by hand, and the fact that a couple of lines were not trimmed is not a deficiency of the program with which it was created.
    2. The drawing on the right does not look as 'trimmed and dimensioned in a modern program'. It could have been trimmed and dimensioned on the other program used on the left, too; plus, not of them is dimensioned yet, plus both programs are being released at the same time.
    3. You misplaced one of the vertical lines, the one that is on the right side of the bolt. So your traced drawing is not a reliable reproduction of the original, whatever it represents. If that happened to you with a simple straight line while tracing over a small bolt detail, imagine how many lines you will misplace trying to trace over a large site plan full of splines.

    Alfredo Medina
    info@planta1.com
    ----------------------------------------------------------------
    Planta1 Revit Online Consulting | info@planta1.com
    Please use plain text.
    *Matt Stachoni

    Re: Import CAD

    02-21-2010 08:00 AM in reply to: RBartsch
    And in regards to the OP's desire to redraw a title block in Revit, you are
    pretty much left with option #1 (tracing a bitmap), option #2 (tracing the CAD
    linework) or a new option #3, importing and exploding the linework (easy but not
    recommended as a best practice).

    It's up to the user to decide which option is the sanest and most efficient.

    However, if I saw one of my employees turning a perfectly decent AutoCAD drawing
    of a bolt fastener into an image, importing it into Revit, and taking the time
    to trace over it, that person would not have that job for very much longer.

    Matt
    matt@stachoni.com


    On Sun, 21 Feb 2010 06:35:12 -0800, Alfredo_Medina <> wrote:

    >Dear Vector2
    >
    >What our friend is saying about a Lisp routine that does the job of creating the topography is true. I wrote one for me, too, and I explain its use to my students in my courses. Revit provides 3 ways of making a site: 1) By manually adding points with elevations , 2) By importing a drawing, and 3) By reading a list of points.
    >
    >The method that you are proposing (tracing over) has to do with option # 1, but it will be extremely awkward to trace over an image of a site plan, not only painfully slow and inaccurate, but also risky and unprofessional. Have you really tried? Those plans have some difficult curves, it will be a nightmare to trace it over, don't even suggest that.
    >
    >Option # 2, importing a drawing; you bring a 3D wireframe of a site plan, and then tell Revit to use that import to create the topography. Once created, you may erase the imported drawing. Nothing wrong with that, if it works.
    >
    >The other option, # 3, is the one that works with the Lisp routine. This option has the advantage that you don't need to import any CAD drawing, which is what you and others are against to. All you need is some previous work in AutoCAD before going into Revit. In AutoCAD, you need a 3D wireframe of your site plan; have all the contours elevated as per the actual elevations. Then, in AutoCAD, you run the Lisp routine. It only takes seconds to generate a list of all the x,y,z coordinates of the first and endpoint of every line or polyline segment. The routine saves the list in a .txt file. Then close AutoCAD, go to Revit > Site view > Massing and Site tab > Toposurface > Create from import > Specify points file > select the .txt file created by the Lisp routine > and Voilá! ...your topography is created in an instant. The result is accurate, since it is created with actual coordinates. Now compare this with tracing over an image!
    >
    >Alfredo Medina
    >Online training of
    >AutoCAD & Revit Architecture
    >www.planta1.com
    Please use plain text.
    *The Dark Princess

    Re: Import CAD

    02-21-2010 09:37 AM in reply to: RBartsch
    the lisp in question studies the entity picked (nentsel) and grabs the
    z-data accordingly.

    if it is a 3dface then it extracts the list of points, eliminates duplicates
    if ti is a text or mtect it converts the value to a z coordinate and
    searches for other entities of similar layers/values etc
    if it is an attribute it searches for similar blockas and attributes and
    does the same thing

    if it is a 3dpoint it simply extracts it
    splines/plines with text near them for height are converted into data points
    at an equal interval along the spline /plines
    if the spline/plines z is constant it will search for text near the points
    and if only one found attempt to extract z info - otherwise it pauses and
    asks the user to enter a z or indicate which object has the appropriate z
    value for that entity.

    output is to a x,y,z or z,x,y file, or create 3dpoints etc

    we received a 3dface representation of mount royal near mcgill uniuversity
    that contain about 40,000 3dfaces. the user was able to create the .txt
    x,y,z file in seconds.

    --
    TDP

    First things first, but not necessarily in that order.

    The Doctor
    wrote in message news:6341099@discussion.autodesk.com...
    Dear Vector2

    What our friend is saying about a Lisp routine that does the job of creating
    the topography is true. I wrote one for me, too, and I explain its use to my
    students in my courses. Revit provides 3 ways of making a site: 1) By
    manually adding points with elevations , 2) By importing a drawing, and 3)
    By reading a list of points.

    The method that you are proposing (tracing over) has to do with option # 1,
    but it will be extremely awkward to trace over an image of a site plan, not
    only painfully slow and inaccurate, but also risky and unprofessional. Have
    you really tried? Those plans have some difficult curves, it will be a
    nightmare to trace it over, don't even suggest that.

    Option # 2, importing a drawing; you bring a 3D wireframe of a site plan,
    and then tell Revit to use that import to create the topography. Once
    created, you may erase the imported drawing. Nothing wrong with that, if it
    works.

    The other option, # 3, is the one that works with the Lisp routine. This
    option has the advantage that you don't need to import any CAD drawing,
    which is what you and others are against to. All you need is some previous
    work in AutoCAD before going into Revit. In AutoCAD, you need a 3D wireframe
    of your site plan; have all the contours elevated as per the actual
    elevations. Then, in AutoCAD, you run the Lisp routine. It only takes
    seconds to generate a list of all the x,y,z coordinates of the first and
    endpoint of every line or polyline segment. The routine saves the list in a
    .txt file. Then close AutoCAD, go to Revit > Site view > Massing and Site
    tab > Toposurface > Create from import > Specify points file > select the
    .txt file created by the Lisp routine > and Voilá! ...your topography is
    created in an instant. The result is accurate, since it is created with
    actual coordinates. Now compare this with tracing over an image!

    Alfredo Medina
    Online training of
    AutoCAD & Revit Architecture
    www.planta1.com
    Please use plain text.
    Valued Mentor
    vector2
    Posts: 2,058
    Registered: ‎03-28-2009

    Re: Import CAD

    02-21-2010 02:26 PM in reply to: RBartsch
    Alfredo-

    nice to see you from time to time..

    i notice you make no case for importing
    DWG lines into a revit project..

    the only thing i understand you to be
    saying is that eventhough i made the
    detail look much better- it still might
    not be perfect..

    but imagine what it would be like if i had
    linked it in and snapped to the exact same
    lines.. it would have been the exact same
    sloppy AutoCAD mess PLUS my whole revit
    project file would have been contaminated..

    and don't kid yourself about that's not how they
    draw AutoCAD lines- i pulled that out of a huge
    library folder of AutoCAD details used by a 10
    person arch firm for the last several years..
    some of the details look okay- but many do not..

    listen to logic Alfredo- ANYTHING drawn in
    AutoCAD needs to be rebuilt from scratch in
    revit- and the best and easiest way to do that
    is to lay out all the lines over the top of an
    image of those lines and then clean them up..

    NOBODY has yet made a case for doing it
    a better way.. because i don't think they can..
    but that is what i am asking to see..
    Please use plain text.
    *Murph

    Re: Import CAD

    02-21-2010 02:41 PM in reply to: RBartsch
    Well in heck do you think that images comes from to start with? Are you
    going out on a site with a cutoff saw and a camera taking pictures to get an
    image? Or do you think Photoshop or some other image software is going to be
    any more "exact"?

    --

    Murph
    http://map3d.wordpress.com/


    "vector2" wrote in message news:6341191@discussion.autodesk.com...
    Alfredo-

    nice to see you from time to time..

    i notice you make no case for importing
    DWG lines into a revit project..

    the only thing i understand you to be
    saying is that eventhough i made the
    detail look much better- it still might
    not be perfect..

    but imagine what it would be like if i had
    linked it in and snapped to the exact same
    lines.. it would have been the exact same
    sloppy AutoCAD mess PLUS my whole revit
    project file would have been contaminated..

    and don't kid yourself about that's not how they
    draw AutoCAD lines- i pulled that out of a huge
    library folder of AutoCAD details used by a 10
    person arch firm for the last several years..
    some of the details look okay- but many do not..

    listen to logic Alfredo- ANYTHING drawn in
    AutoCAD needs to be rebuilt from scratch in
    revit- and the best and easiest way to do that
    is to lay out all the lines over the top of an
    image of those lines and then clean them up..

    NOBODY has yet made a case for doing it
    a better way.. because i don't think they can..
    but that is what i am asking to see..
    Please use plain text.
    Valued Mentor
    vector2
    Posts: 2,058
    Registered: ‎03-28-2009

    Re: Import CAD

    02-21-2010 03:19 PM in reply to: RBartsch
    Murph-

    i'm sorry but you are making absolutely
    no sense whatsoever..

    the issue is about how to get already
    drawn AutoCAD details into a revit file..
    Please use plain text.
    Member
    Posts: 5
    Registered: ‎12-02-2009

    Re: Import CAD

    02-22-2010 04:42 AM in reply to: RBartsch
    vector2, I could care less if you are tracing a bolt detail into revit, my concern is that you are suggesting tracing a copy of an existing surveyor's work in order to design a building or site from. And in response to your comment about how others draw lines; I think that maybe you need to not compare how the rest of us draw to some 10 year old details drafted by some rookie. I would be curious to know how long you have been in the CAD world, as everyone knows, there was a time when those sloppy lines (as you call them) were all we had to draft with, not to mention, those of us who started drafting by hand.

    I do agree that there needs to be a better way to do this.

    Mr. Medina, could you send me a copy of the lisp routine you spoke of?

    Just a Surveyor...
    Please use plain text.
    *Brian Winterscheidt

    Re: Import CAD

    02-22-2010 06:31 AM in reply to: RBartsch
    On 2/21/2010 1:08 AM, The Dark Princess wrote:
    > I have a lisp that takes acad survey and creates all 3d points necessary for
    > revit to create topography in seconds and far more accurately...

    I have a question on these lisp-to-point methods and resulting accuracy
    in Revit:

    I have encountered problems on creating topo in Revit where all points
    obtained from a linked .dwg file are accurate, but Revit does not
    triangulate/connect these points in the same order as the original .dwg,
    resulting in inaccurate topography, particularly in areas of steep grade
    change (retaining walls, etc.).

    Do your results from this lisp method overcome that, or have you ever
    encountered this problem?

    --
    Brian Winterscheidt
    LWPB Architecture
    Oklahoma City, Oklahoma
    Please use plain text.
    Valued Mentor
    vector2
    Posts: 2,058
    Registered: ‎03-28-2009

    Re: Import CAD

    02-22-2010 11:56 AM in reply to: RBartsch
    mike-

    who said anything about "surveyor's work"?
    Please use plain text.