Export Phases to DWG

[DaveP]

I'm looking for some info on Exporting to DWG. Specifically regarding New, Existing, Demo.
I found this thread:
http://forums.augi.com/showthread.php?t=2327&highlight=export+demo
but no real resolution:

My approach has been, if necessary, to export existing, demo and new work separately, from separate formatted views and rejoin them in AutoCAD or Microstation afterward.

You don't have phase aware control over objects when you export so walls are going on A-wall whether it is existing or new...true in 5.0 and 5.1, I've not observed any change in this with 6.0 so I'm assuming it remains true.

I should probably mention that we have to approach it this way because our engineers have expectations regarding where stuff will be and we are attempting to minimize confusion by abiding by their wishes.

It's a relatively simple task to reference the discreet phases of work together and each export can have it's own criteria for layer and color. Just set up different export rules for each.I also don't see anything about it in 7.0
Anybody know of anything new, or is this something I should drop into the WishList?

[Steve_Stafford]

...I'm looking for some info on Exporting to DWG...It's been a long time since that post. Keep in mind my comments then were based on export to Microstation DGN primarily and in the version that Revit support (J or 7) Microstation has 63/4 levels (layers)(sheesh, I can't remember which now...63 64?) So Revit couldn't create new layers for phased objects like it can for AutoCAD.

Newer releases have made some good effort on dwg export. One big improvement is how exported blocks are done. They used to create a discrete block instance for every object like a window (common name with a number suffix). Now Revit provides a copy of identical blocks instead. This makes it a lot easier to make a change to a block in AutoCAD and propogate the change to all the "same" blocks. Always more to do though.

I've posted a couple dwg files that I exported the other day. You can see how 6.1 creates a plan for each phase filter I used...Show All and Show Previous & New.

A fundamental issue for us that remains is BYLAYER status for objects that are part of complex entities that Revit understands how to display internally but over-rides on export. You'll see that walls are segregated nicely by layer and phase but the hatch is part of the same layer and color is "forced". This makes it difficult to manage visibility when referenced into another file or just for the sake of visibility while working on the file.

From a "backgrounds" perspective this isn't really a problem if you set up your export views so hatches aren't displayed etc., assuming that's possible. If you have to let someone else work with the file to continue to do design work it will annoy them.

Experiment a bit since every office has slightly different habits when it comes to AutoCAD standards. See how it works for you all.

HTH