Project DWG Link vs Family DWG Import

[Anonymous]

Hello,

Within Revit projects, there's the option of linking or importing CAD. I'm aware that one should not import CAD to projects, due to it importing all kinds of undesirable information which may stay behind even after you delete the detail and affect performance. Linking CAD alleviates this by keeping it all together as one bundled object, however Revit families only have the CAD Import option?

1. Why do families only allow for CAD Import in families?

2. Why does CAD Import in families seem to behave as a grouped object like CAD Link in projects?

3. Is it also bad to import CAD to families, or are you essentially linking the CAD file?

Thanks.

[Anonymous]

Hello,

Within Revit projects, there's the option of linking or importing CAD. I'm aware that one should not import CAD to projects, due to it importing all kinds of undesirable information which may stay behind even after you delete the detail and affect performance. Linking CAD alleviates this by keeping it all together as one bundled object, however Revit families only have the CAD Import option?

1. Why do families only allow for CAD Import in families?

2. Why does CAD Import in families seem to behave as a grouped object like CAD Link in projects?

3. Is it also bad to import CAD to families, or are you essentially linking the CAD file?

Thanks.

[nicholas_seibert]

Hi Florisvisser5049

Yes, there are some do's and don't of working with DWGs.  The first question is what do you want to use it for.  That will help make some decisions.  In general I tend to not Import a DWG, because it is easy to lose track of it in your file.  There is not an "import manager" or something like that to track down DWG's that you have imported into your file.  This can negatively impact performance if you end up having extra dwg's in your file.  If it is a Link you can manage them in the Manage Links dialog.

The other thing to keep in mind is when you bring in your DWG there is the option for "Current View Only", the other option meaning it is in your model, so it will appear everywhere...3D,Elev,section views and floor plans. See this video on that below.  Depending on the use of your DWG this option might be better for you.

https://knowledge.autodesk.com/support/revit-products/getting-started/caas/screencast/Main/Details/3...

Families in general don't support any links.  Bringing a DWG into a project via a family has it's benefits, if the DWG is 3D then it will cut and respond the things like View Range and Far Clip.  That is probably the biggest benefit to using a family and typically why people go that direction(i think).  The family can also be managed and removed easily from the project if it's a family via the project browser.  Once again the family doesn't support links, so it would be a manual process to update the DWG if it changes.

One final general rule, try to make sure your DWG is as clean as possible.  Anything in the DWG that is way off in space or a layer that is hidden will give you some headaches in Revit.  My suggested would be to delete anything in the DWG you don't need and then purge the DWG.  Thaw, turn on all layers and do a zoom extents to make sure you are only seeing what you want to see.

Hopefully this helps, if you run into something else let us know.

Thanks!

[nicholas_seibert]

Hi Florisvisser5049

Yes, there are some do's and don't of working with DWGs.  The first question is what do you want to use it for.  That will help make some decisions.  In general I tend to not Import a DWG, because it is easy to lose track of it in your file.  There is not an "import manager" or something like that to track down DWG's that you have imported into your file.  This can negatively impact performance if you end up having extra dwg's in your file.  If it is a Link you can manage them in the Manage Links dialog.

The other thing to keep in mind is when you bring in your DWG there is the option for "Current View Only", the other option meaning it is in your model, so it will appear everywhere...3D,Elev,section views and floor plans. See this video on that below.  Depending on the use of your DWG this option might be better for you.

https://knowledge.autodesk.com/support/revit-products/getting-started/caas/screencast/Main/Details/3...

Families in general don't support any links.  Bringing a DWG into a project via a family has it's benefits, if the DWG is 3D then it will cut and respond the things like View Range and Far Clip.  That is probably the biggest benefit to using a family and typically why people go that direction(i think).  The family can also be managed and removed easily from the project if it's a family via the project browser.  Once again the family doesn't support links, so it would be a manual process to update the DWG if it changes.

One final general rule, try to make sure your DWG is as clean as possible.  Anything in the DWG that is way off in space or a layer that is hidden will give you some headaches in Revit.  My suggested would be to delete anything in the DWG you don't need and then purge the DWG.  Thaw, turn on all layers and do a zoom extents to make sure you are only seeing what you want to see.

Hopefully this helps, if you run into something else let us know.

Thanks!

[Anonymous]

Thanks for your response @nicholas_seibert.

Just to clarify: the main reason importing CAD is bad practice is because one loses track of all the imported CAD objects? Layer information, etc. doesn't actually get lost in the file? Basically I want to know if I import a CAD drawing to a family to use as guidelines for a Revit family and then delete the CAD when I'm done, that it won't leave behind any undesirables embedded in my family, like layer information, etc.? 

[Anonymous]

Thanks for your response @nicholas_seibert.

Just to clarify: the main reason importing CAD is bad practice is because one loses track of all the imported CAD objects? Layer information, etc. doesn't actually get lost in the file? Basically I want to know if I import a CAD drawing to a family to use as guidelines for a Revit family and then delete the CAD when I'm done, that it won't leave behind any undesirables embedded in my family, like layer information, etc.? 

[Anonymous · Accepted solution]

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@Anonymous wrote:

Thanks for your response @nicholas_seibert.

Just to clarify: the main reason importing CAD is bad practice is because one loses track of all the imported CAD objects? Layer information, etc. doesn't actually get lost in the file? Basically I want to know if I import a CAD drawing to a family to use as guidelines for a Revit family and then delete the CAD when I'm done, that it won't leave behind any undesirables embedded in my family, like layer information, etc.? 

---

I do this sometimes...then I copy/paste all the revit elements from one file to another....just to make sure nothing from the DWG follows into the project.

Sometimes though I cleanup the DWG as much as I can and actually keep the DWG in the family.  A good example are consultant logos that Revit's fill patterns cannot duplicate because of the "line to small" issue.

[Anonymous · Accepted solution]

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@Anonymous wrote:

Thanks for your response @nicholas_seibert.

Just to clarify: the main reason importing CAD is bad practice is because one loses track of all the imported CAD objects? Layer information, etc. doesn't actually get lost in the file? Basically I want to know if I import a CAD drawing to a family to use as guidelines for a Revit family and then delete the CAD when I'm done, that it won't leave behind any undesirables embedded in my family, like layer information, etc.? 

---

I do this sometimes...then I copy/paste all the revit elements from one file to another....just to make sure nothing from the DWG follows into the project.

Sometimes though I cleanup the DWG as much as I can and actually keep the DWG in the family.  A good example are consultant logos that Revit's fill patterns cannot duplicate because of the "line to small" issue.

[nicholas_seibert · Accepted solution]

The only thing that i know it will leave behind is the Line Patterns.  Unfortunately those are not cleaned up in a purge unused and they need to be delete one by one in the Line Pattern dialog under Manage>Additional Settings

I just did a double check and nothing else is jumping out as being left behind.

Thanks

[nicholas_seibert · Accepted solution]

The only thing that i know it will leave behind is the Line Patterns.  Unfortunately those are not cleaned up in a purge unused and they need to be delete one by one in the Line Pattern dialog under Manage>Additional Settings

I just did a double check and nothing else is jumping out as being left behind.

Thanks

[Anonymous]

Thanks for the assistance Gents

[Anonymous]

Thanks for the assistance Gents