revit in plain english

Friday, July 25, 2014

Coordinates, Base Points, Surveys and Making a Toposurface

This is a repost from four years ago with some updates...

If you browse through the forums, blogs, how-to videos and books you will find a wealth of information on the above titled subject. And it's all conflicting. It's just about the most confusing subject you will encounter in Revit. I will now add my voice to the many others. The method I'm proposing can be boiled down to a common point which is graphically represented in all files. You will then line everything else up based upon that. This technique will also work if Shared Parameters are used.


The architect must set this up BEFORE anything is done in Revit. No modelling, importing, linking, not anything.
Step 1. Set up the AutoCAD
AutoCAD survey drawings usually have 3D contours and 2D drafted information. The 2D stuff is at 0 Z elevation, the 3D is at it's actual height off of Sea Level. The 0,0,0 or Origin can be anywhere and sometimes it relates to something but sometimes not. We will be changing this.
Save as.
Give new name.
Move everything so the 0,0 is at the bottom left (don't adjust the Z). This could be at the property line intersection.
Make sure there is nothing outside of a 20 mile radius sphere from the 0,0,0. That means you will need to take a look in the Z.
Draw a circle on an individual layer at 0,0,0. This will mark zero for both the 2D and 3D dwgs you will end up with.
Optional: Rotate these to Project North. Make sure there is a North Arrow visible.
Break this file into two files, one with 2D plan info and the other with 3D contours. You can use the wblock command or saveas.
Of course, you should audit and purge the AutoCAD file as well.

Step 2. Not in Revit yet...

Get the longitude/latitude information relating to the AutoCAD site file.
If you don;t have it, open Google Earth and go to the address. Find the longitude/latitude of the corner of the site that corresponds with the 0,0, write it down.

Step 3. Revit Architecture

Revit has a 20 mile diameter of where you can draw or even import. You cannot have anything outside of that.

Manage Place and Locations will assign the Longitude/Latitude numbers to your Revit 0,0 (Origin)
Revit 0,0,0 is found by default at the centre of the elevation markers. It's also the default location of the Project Base Point and Survey Base Point. The Revit origin can not be moved.

Make a view called AutoCAD Site Plan.
Import the 2D AutoCAD. Origin to Origin. Current View Only turned on. You cannot change Revit's origin. The origin can be found at the nexus of the elevation markers in plan. This point is dead centre on your screen when you start from a standard Revit Template.
Then Import the 3D AutoCAD Contours, Origin to Origin. Current View Only turned off. You won't see this file yet, it's above your view.
Go to elevation, move the contours down to level 1.
Go to the site plan view.
Confirm that your Survey Base Point(triangle with an x) is at the centre of the circle you drew in AutoCAD.
Click on the Project Base Point (a blue circle with an x). Click in the 'Angle to True North' and type the difference between your project north and the true north. You may have to type a negative in front of the degrees to get the expected results.
The Project Base Point and Survey Base Point will be in the same place. That's fine.
You may also want to draw two Reference Planes based on the centre of the AutoCAD circle which is also the origin. Name them something logical.
Adjust your elevation markers and datums to focus on where your building will be.
Start drawing grids and modelling etc.
Step 4. Other Linked Revit Files...
Start your new Revit Structure or MEP file.Very first thing you do is link the Revit Architecture file (which we just setup) Origin to Origin.
Check that the Z has come in correctly.
Adjust your elevation markers and datums to focus on where your building will be.
Draw Grids and Levels over top of the linked Revit Architecture as needed. 
Start drawing grids and modelling etc.
About Exporting back to CAD...
When exporting back to AutoCAD the origins of both AutoCAD and Revit will line up as long as you have used the default location of the Project Base Point.

Create Topography in REVIT from an AutoCAD file 


pdf instructions 
video instructions


Monday, July 14, 2014

Another Visibility Issue: View Range not Affecting Structural Slabs




Autodesk Revit Development team, please fix this bug. Okay maybe it's not exactly a 'bug' but it is a feature which causes confusion and delay.



Model elements located outside of the view range generally are not shown in the view. The exceptions are floors, stairs, ramps, and components that stay or are mounted on the floor (like furniture). These are shown even when slightly below the view range.
Slab edges are shown when their bottoms are within a tolerance of the primary view range bottom.

Foundation slabs and structural floors located outside the view range use an adjusted range that is 4 feet (approximately 1.22 meters) below the bottom of the primary range.Floors are drawn with the Beyond line style if the floor exists within this adjusted range. 


Here's the credit: http://forums.augi.com/showthread.php?137848-Slab-showing-when-below-View-Depth

Friday, April 04, 2014

Measuring Revit Skills

Is there a standard measure of an individuals Revit skills? Would be nice to track individual and office progress. Might even be a cause for bragging rights. Below is a look at this from my perspective. After filling out the spreadsheet a person ends up with a Revit Score. Your comments are welcome. If you would like a copy of the Excel file in order to make suggestions send me an email jpolding@solidcad.ca.





Monday, March 17, 2014

Hidden Lines not Wider than Category

In Object Styles (or Visibility/Graphics), the Structural Framing Category, Projection Line Weight is set to 4. This means that the Hidden Lines Subcategory cannot be set higher than 4. Actually, it can be set higher than 4 but will not display higher than 4. 

Structural Framing Lineweight not Changing in Section

Imagine you have a Girder and a Joist as defined by Revit. You would like the Joist to be a thinner lineweight than a Girder, in every view. Not possible by default. Changes to the Subcategories of Structural Framing in Object Styles only affect plan, NOT SECTION. Subcategories of Windows, Doors, Wall Sweeps and other objects are affected by changes in Object Styles, just not Structural Framing. How do we work around this programming error? Edit the Structural Framing Family, make a new Subcategory, Assign the geometry to this new Subcategory. Now in the Revit Project file, open Object Styles and edit the lineweights of the new Subcategory you just made.
Anyone know why this is the way it is? Anyone have a better workaround?

Friday, March 07, 2014

Revit and Landscape Design

When asked 'does Revit do Landscape Design?' some will immediately say 'No!'. They are quick to point out it's 'limited' site tools. But I think we need to ask 'limited compared to what?'. AutoCAD doesn't come close to the overall drafting efficiency that Revit provides. Plus, AutoCAD has no automated site tools and it's 3D tools are definitely 'limited'. How about Sketchup? Sketchup has a similar 3D toolset to AutoCAD, granted it's graphics are much nicer. Still, both Sketchup and AutoCAD  slow to crawl when dealing with large file sets. AutoCAD Civil 3D is a wonderful tool, it handles large files and has excellent 3D and BIM tools. Civil 3D should be the tool of choice for landscape architects, problem is it's relatively hard to set up and use.

So to what are we comparing Revit's tools? To Revit mostly. All of us in the Revit community have been asking for improved site tools in Revit from day 1. This is mostly because of the potential we all see. Has Autodesk done anything about it? As of today, not much. Yet Revit's 3D and BIM site tools are better than AutoCAD and Sketchup and are easier to use then AutoCAD Civil 3D. So can Revit be used for landscape design? Yes, landscape designers and architects are using this tool around the world with success. Below are some examples:

Revving up for Revit, Building Information Modeling for Landscape Architecture 
Kudela and Weinheimer Landscape Architecture

Site Engineering for Landscape Architects
By Steven Strom, Kurt Nathan, Jake Woland

BIM AND LANDSCAPE ARCHITECTURE - IMPACT AND ISSUES
Posted on July 12, 2013 by Stephen Blacklock

Landscape Architecture in BIM
A Landscape Architects Revit Blog

Autodesk Revit Architecture...for landscape architects?