Best Way to Eliminate Classes from dwg. Imports?

[Rossford 23]

Thought about putting this in the "depressed" thread, but wanted to get more attention, since its not about X refs.

I get files in DWG and they have millions (well, thousands) of classes. I have my own class and layer system.

I was reading the manual last night and was intrigued by class and layer mapping.

Is that or some other work flow the best way to get dwg imports to convert to my class and layer system?

I got one yesterday, and while the layer was "grading" as mine would be, it had a bunch of classes like "level 10, leval 15" that didn't really convert to the actual topo levels, or even major and minor contours. For that matter, some non contour lines were nurbs and meshes, while the contours were 2D.

Of course, I know I can't make every one draft to my standards, but how do you guys and gals import dwg and make them useable?

[CipesDesign 76]

As far as I know there is no magic solution. It is very dependent on the quality of the drafting you are importing, especially the quality of the organization (which generally tends to be less than perfect, shall we say...). One way of slightly simplifying things is to add a prefix to all imported classes, for example: "Survey-". At least that allows the easy segregation of "their" stuff and yours. The prefix can be added during the import process, see attached...

[michaelk 275]

I never import a dwg directly into my drawing for exactly that reason.

You might find this workflow useful:

1. create a blank document. Import the dwg. Make sure the scale is correct. Save and close.

2. In your real drawing create a design layer viewport - external source and navigate to the first drawing.

Now that viewport's OIP will have access to all the classes of the original dwg, but those classes will not be in your drawing's navigation palette.

The link between the two vwx drawings stays live. So if you go into the source vwx drawing and delete something, the target vwx drawing will update the next time it is opened or whenever you manually tell it to update.

hth

mk

[Pat Stanford 690]

If you really need to work with the data from the DWG files, then you will have to do the cleanup, probably manually.

If you just need to have reference to their data, import the DWG into a VW file. Then use a Design Layer Viewport to reference the data into your working file. All of their classes will be encapsulated in the viewport and not interfere with your class structure.

If you need to compress their data into your layers, when you delete a class you get the option to reassign those objects to a different class. You can even select multiple classes at once and get all of the objects in all the classes reassigned in one go.

[Ozzie 17]

I import dwg layers as classes and assign them a prefix of ?z? ? keeps them to the bottom of my Class structure and out of the way

I NEVER bring a dwg into an existing drawing in VW ? too dangerous with naming conflicts etc especially if the dwg is large with lots of resources layers etc

I mostly create a Design Layer View Port and reference to them and draw over the top of them

If I need to I ?visit? that file and grab geometry from it that I need but am always wary when bringing it into my VW file attributes may not be set up as I want them ? by Class - whatever

It is difficult but always important you keep your VW file clean and light and know exactly what is in your working file

Had a large AutoCAK file last week that was a main drawing with several xrefs ? just a nightmare

Another thing because lots of dwgs are drawn on a black background ? be careful when bringing geometry in you know exactly what you?re getting

Sometimes I will bring geometry into a new temporary file Copy / Paste in Place ? clean up, get Class working as I want it and then transfer into my VW working drawing

Copy / Paste in Place above ? think about drawing origins of both files

[Jonathan Pickup 215]

you can use the class and layer mapping command to remove or merge classes and layers.

[Rossford 23]

Thanks for all the answers.

Jonathan, I quickly read about the class and layer mapping in my manual from the 2008 version. I trust it works about the same in 2011?

Might be a great monthly topic on your subscriber site, hint, hint......

[Jonathan Pickup 215]

If you are a subscriber, go to the back issues and download 0806 - June 2008 Class and Layer Mapping.

[Rossford 23]

Jonathan,

I am and I will!

Jeff

[Jonathan Pickup 215]

Thank you.

Do you join the online sessions? next month is site modeling

[Rossford 23]

Thanks, I have and I will. Site modeling is what I try to use most, not always successfully. I will check the schedule.

[M.CH 0]

Best way I find to resolve this is to open a new VW file and then import the DWG file. Save that file

Then on your working file use Create Viewport, on a design layer, then select source and create the dwg as reference file.

You can then control what you see through the VP dialogue box.

[Ozzie 17]

Especially if you are a magician because you cannot select anything in the external file to know easily what class or layer the geometry is in

Dunno how or if VW can ever solve this one easily

Having both files open at once seems to be the only way around it

[bcd 215]

...you cannot select anything in the external file to know easily what class or layer the geometry is in

Dunno how or if VW can ever solve this one easily

The trial&re-trial works in a clunky way to do this:

Select your referenced DLVP

In the OIP Click Layers

Turn off/on layers and

click Preview to identify the layer of interest

Press Cancel to dismiss the changes.

Then edit again to set the visibility as required.

Likewise for classes

I typically turn a list of classes on/off at a time to narrow down the search.

Yes, it would be very nice if the Visibility tool could control Layers & Classes within a referenced Viewport.

[Ozzie 17]

[quoe=BCD]Yes, it would be very nice if the Visibility tool could control Layers & Classes within a referenced Viewport.

Or directly select them as an option perhaps from the main file to know what they are

The way it is now is tedious but hey at least we can have external references