Importing CAD

[mlaubacher]

Does anyone have any tips or good general practices when starting a set of plans based on imported CAD drawings?  My computer has all the horsepower it needs, but it has a hard time with real involved drawings from Auto Cad.

Thanks!

[Alaskan_Son]

This is a rather involved subject, but here are a few of the key things to consider...

 

A.  Whether or not you actually need all the imported layers and layer settings.

B.  The fact DWG files can include tons of CAD blocks that aren’t actually used in the drawing (things you may or may not want but things that can certainly boost your file size).

C.  The fact DWG files oftentimes contain tons of CAD blocks that ARE used in the drawing.  Problem with these as that you can’t snap to them.  

D.  The fact various items may or may not be drawn or dimentioned accurately and that various wall layers may or may not be included in the drawing.  This is very important to consider when placing your new walls.

E.  The fact we have a CAD To Walls tool available.  You may or may not want to use it.

F.  The fact multiple floors may come in overlapped on a single floor in Chief.

G.  The fact you may or may not know what any given layer is used for.

 

 

 The basics of my personal workflow are approximately as follows:

 

1.  Import the desired DWG file including all existing layers and layer settings but excluding any CAD blocks not actually referenced in the drawing.  If you happen to know what the various layers are used for you could optionally exclude some of them or map the layers right away, but I would be super careful about doing this since CAD blocks and their internal line work can reside on different layers (just like they do in Chief).  Similarly, I would also leave out the unnecessary CAD blocks unless you want/need them for some other unrelated purpose.  

 

2.  Explode CAD blocks, move linework to your own custom layer(s), and adjust the settings as desired for color, line style, drawing group etc.  Then, group by group, Cut/Paste Hold Position all that linework to a NEW plan, placing it onto the correct floors, and locking layers as necessary.  This will ensure you only bring over only exactly what parts you want, AND it will keep your layer sets as clean as possible.  

 

3.   As you go of course, you are deleting things you don’t need. 

 

4.  With my all the desired linework in the new plan, on the desired layers, and using the desired settings (in my case I put onto a very minimal number of layers—sometimes just one (all set to be some shade of gray) and lock layer(s).

 

5.  Figure out how walls have been dimensioned, which layers were included in the drawing (drywall, framing, siding, etc.) and choose or create the appropriate wall type(s).   You have to be very careful with this because I find many CAD-based drawings contain a lot of inaccurate wall thickness information and you have to adjust accordingly.

 

6.  Set the Resize About setting for walls so that you can snap to a special group of lines.  This can make very quick work of the tracing part.

 

7.  Place windows and doors (sometimes I actually do this as I go).  

 

8.  Same as above for cabinets, toilets, fixtures, etc.  

 

9.  Build roofs and foundations.

 

 

 That’s the basics anyway. For me, the most difficult part is really just cleaning up the line work so that you have all the information you need, ONLY the information you need, and have it all in a usable, easy to read, snappable format.  Then the tracing is quick and easy.  

 

 

 With regard to the CAD To Walls feature, it can be handy for quick conversion in some cases, but it still requires a lot of proper cleanup and layer mapping, and the biggest problem is that wall definitions, windows, and doors don’t always end up correct so you end up having to re-check everything anyway. In my opinion this is just better to do as you are tracing.   My thoughts are that we don’t want to depend TOO much on our software. It’s good to double/triple check certain steps and if you can use a sort of built in double/triple checking process, that is a lot better than just double checking.  The problem with a regular double check is this:  If you missed it the first time, you’re likely to miss it again he second unless you’re using an entirely different checking method—in this case both manually placing by hand and then glancing back over using a visual scan (with or without utilizing special layer settings in the process).  

 

 

[tommy1]

Well said Michael. A couple of other things I do is initially import the dwg to a cad detail so I have the original dwg. Then I'll send that dwg from the cad detail to plan view for editing. I generally be sure that when sending to plan view, I be sure that the front left corner is not too far from absolute 0",0". AutoCad files often show interior walls 4" think and they dimension to the framing (main layer). Exterior walls will normally be siding or stucco unless they show a thickness for brick. I have also had dwgs where the placement of windows and doors in plan didn't match up with the elevations. I've also had roofs from the dwgs didn't work as shown show just beware that this could happen. Hopefully they supplied ceiling heights, floor thicknesses and roof plate heights. I also generally trace the dwg and not use cad to walls. I always put the lines of the dwg on its own layer so I can turn it off when I'm finished using it and lock the dwg (unblocked) so I can trace it and not accidentally move a cad line. 

[DH7777]

 

 

 

 

 

 

 

 

 

 

 

 

 

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On 1/27/2019 at 10:09 PM, Alaskan_Son said:

This is a rather involved subject, but here are a few of the key things to consider...

 

A.  Whether or not you actually need all the imported layers and layer settings.

B.  The fact DWG files can include tons of CAD blocks that aren’t actually used in the drawing (things you may or may not want but things that can certainly boost your file size).

C.  The fact DWG files oftentimes contain tons of CAD blocks that ARE used in the drawing.  Problem with these as that you can’t snap to them.  

D.  The fact various items may or may not be drawn or dimentioned accurately and that various wall layers may or may not be included in the drawing.  This is very important to consider when placing your new walls.

E.  The fact we have a CAD To Walls tool available.  You may or may not want to use it.

F.  The fact multiple floors may come in overlapped on a single floor in Chief.

G.  The fact you may or may not know what any given layer is used for.

 

 

 The basics of my personal workflow are approximately as follows:

 

1.  Import the desired DWG file including all existing layers and layer settings but excluding any CAD blocks not actually referenced in the drawing.  If you happen to know what the various layers are used for you could optionally exclude some of them or map the layers right away, but I would be super careful about doing this since CAD blocks and their internal line work can reside on different layers (just like they do in Chief).  Similarly, I would also leave out the unnecessary CAD blocks unless you want/need them for some other unrelated purpose.  

 

2.  Explode CAD blocks, move linework to your own custom layer(s), and adjust the settings as desired for color, line style, drawing group etc.  Then, group by group, Cut/Paste Hold Position all that linework to a NEW plan, placing it onto the correct floors, and locking layers as necessary.  This will ensure you only bring over only exactly what parts you want, AND it will keep your layer sets as clean as possible.  

 

3.   As you go of course, you are deleting things you don’t need. 

 

4.  With my all the desired linework in the new plan, on the desired layers, and using the desired settings (in my case I put onto a very minimal number of layers—sometimes just one (all set to be some shade of gray) and lock layer(s).

 

5.  Figure out how walls have been dimensioned, which layers were included in the drawing (drywall, framing, siding, etc.) and choose or create the appropriate wall type(s).   You have to be very careful with this because I find many CAD-based drawings contain a lot of inaccurate wall thickness information and you have to adjust accordingly.

 

6.  Set the Resize About setting for walls so that you can snap to a special group of lines.  This can make very quick work of the tracing part.

 

7.  Place windows and doors (sometimes I actually do this as I go).  

 

8.  Same as above for cabinets, toilets, fixtures, etc.  

 

9.  Build roofs and foundations.

 

 

 That’s the basics anyway. For me, the most difficult part is really just cleaning up the line work so that you have all the information you need, ONLY the information you need, and have it all in a usable, easy to read, snappable format.  Then the tracing is quick and easy.  

 

 

 With regard to the CAD To Walls feature, it can be handy for quick conversion in some cases, but it still requires a lot of proper cleanup and layer mapping, and the biggest problem is that wall definitions, windows, and doors don’t always end up correct so you end up having to re-check everything anyway. In my opinion this is just better to do as you are tracing.   My thoughts are that we don’t want to depend TOO much on our software. It’s good to double/triple check certain steps and if you can use a sort of built in double/triple checking process, that is a lot better than just double checking.  The problem with a regular double check is this:  If you missed it the first time, you’re likely to miss it again he second unless you’re using an entirely different checking method—in this case both manually placing by hand and then glancing back over using a visual scan (with or without utilizing special layer settings in the process).  

 

 

I just posted this problem I'm having  "Trying to trace an imported dwg. floorplan. This is what's going. Every time I  draw an exterior wall directly over the floor plan it always places the wall 1/2" off the wall I'm trying to trace over. I grab the wall and gently move it into position and the wall snaps to the other side 1/2". I have turned snap off but realized this is going to be an all-day task trying to manually eyeball all these  3-1/2" walls onto their correct position. I have an 8,000 sqft 4plex I have to create renderings for my boss. I really never have had this issue (to this degree) before. I'm in x11 version. I was using x7 an although I still had this issue I could still get my walls to snap to the line I wanted. Now CA is refusing to let me get exact positioning. Basically, my finish drywall will snap to the edge of framing face or snap to where I have a 1/2 space between the framing face and backside of the drywall. I need to be able to move 1/2" either direction here and its not cooperating. I need help. I have looked into default settings and there is nothing related to this issue that I can see. Any suggestions?"

 

You mention in "6.  Set the Resize About setting for walls so that you can snap to a special group of lines." Would this help in my situation and how do I do this?  

[Alaskan_Son]

17 minutes ago, DH7777 said:

You mention in "6.  Set the Resize About setting for walls so that you can snap to a special group of lines." Would this help in my situation and how do I do this?  

 

Yes.  This will likely solve your problem.  You can find the setting in Edit>Default Settings>Walls>General Wall