Aligning models

[Bryan Thatcher]

After you merge models, how do you align the two. I didn't think Acad and Revit shared a base point, but I moved the Arch to 0,0 (it was way in the upper left of the CAD file) before linking it to Revit. And mechanical started with a CAD file from us with the way off 0,0. And they appear to be the same distance apart as our CAD and Revit. Please advise. Thanks.

[mitch.cornelius]

I would import the CAD file to revit origin to origin, then see the values of the xyz offsets. Merge the files together in navisworks and and plug those xyz values into the "File units and transform" function

[Bryan Thatcher]

OK, the CAD file comes in 681'-4" off in the X direction and 367'-0" in the Y direction. The settings in the screenshot put the mech model way off and changes the Z direction also. Any suggestions? Thanks.

[mitch.cornelius]

Try entering the dimensions in meters instead of feet.I realize the project units are set to feet, but the origin still shows a (m). Excel or google can each make the conversion for you pretty easily.

[Bryan Thatcher]

Still no luck. I don't know why it's affection the Z value. And would that be a positive X and negitave Y or the other way around? Thanks.

[mitch.cornelius]

I don't know either...It seems I have to try a number of different combinations each time until it works.

[rsloyer]

I would import the CAD file to revit origin to origin, then see the values of the xyz offsets. Merge the files together in navisworks and and plug those xyz values into the "File units and transform" function

I have been doing this very successfully, up until my current project.

For whatever reason, the nwc output from Revit of the model has a different origin than the Revit model itself. In fact, the model is even rotated 90 degrees in the vertical plane!

I was able to export a dwg file that maintained the same origin as the Revit model, and then move the origin in the dwg to where I wanted it, but using the dwg file in Navisworks is very far from ideal for a variety of reasons.

I exported a dwf file from Revit after using model slicer to get the parts of the building I wanted and the selection tree is fantastic, even better than the tree you get from an nwc export, but it has the same shifting origin point problem.

Since the files come into Revit differently than they come into Navisworks, there is no accurate way to scale the difference and get the into the right place.

[jspartz]

Measure from the location it's at to the location you want it to be in Navisworks than highlight the file and use the transform objects button in the measure tools. Sounds easy, but usually isn't. You need a matching location in each file, like crosshairs or a box to align with when measuring. I typically transform the Revit model because I have way more AutoCAD models and those are easier to align.

[rsloyer]

Measure from the location it's at to the location you want it to be in Navisworks than highlight the file and use the transform objects button in the measure tools. Sounds easy, but usually isn't. You need a matching location in each file, like crosshairs or a box to align with when measuring. I typically transform the Revit model because I have way more AutoCAD models and those are easier to align.

Therein lies the problem, which is the measure in Navisworks sucks. I have gotten pretty good at the snaps, but it's still nowhere near as good as it needs to be from a contractor's perspective. I have subcontractors that won't even try to use measure because they've gotten so frustrated with it.

[jspartz]

I know what you mean. I add crosshairs for each file, turn off everything else, zoom in as far as possible and pick. Then unhide the items before selecting and doing the transform. It's never off more than 1/256" - typically it's unreadable (displays 0" difference).