Refining the site model

Post date: Feb 16, 2016 8:01:04 PM

I have worked on the site model to make it more complete, to establish a better strategy for editing, and to correct some of the problems that were affecting zooming.

Zooming

First, the problem regarding zooming. The major problem was an inserted AutoCAD file that had problematic extents set to thousands of feet away. I edited the AutoCAD file to delete the offending objects which were apparently 70,000 feet underneath our site (in the center of the earth apparently). Testing in AutoCAD, the file now goes to a reasonable display when I use the Zoom Extents command.

Instead of reinserting the AutoCAD file into the Revit file, I used the Link CAD command. This has two advantages: 1) if we change the AutoCAD file again, we can reload the link and the changes are incorporated in the Revit file; 2) it is possible to unload the AutoCAD file when it is not needed, which speeds performance of Revit. I found some scaling problems and location problems, but for now I have roughly scaled and located the drawing.

Online here are some notes about Revit zooming out too far. I don’t really understand how to make it behave the way that I want it to behave, but, like AutoCAD, the problem seems to be related to having some errant objects located far from the drawing. It is important to delete these. There is something also about using the Zoom to Fit All command, and setting the clipping planes to be No Clip. I found that the Level objects were not very near the site, so I moved them too. Anyway, these many changes have resulted in a model that behaves how I want it to with respect to zooming.

Many projects require this kind of “file scrubbing”. CAD and BIM files come from many sources. Some people are very adept and some people build very sloppy ugly models. It is very important that you build good models that are reusable.

Splitting the model

Although you cannot change the vicinity of our site, I would like you to edit the topography of our site. This makes it necessary to separate the Century Square site from the vicinity. The vicinity can be a fixed, unchanging model with toposurface and building masses. A smaller, faster model of the Century Square site can include a toposurface that can be edited. Revit provides a Split Surface command that allowed me to split the existing toposurface along the site edge. I could then delete the vicinity and save the file as the Century Square site, or delete the site and save a vicinity model.

These two models can then be linked into a project file. The “bind” command can then Century Square model import the site into the project and allow for full editing. The vicinity model can remain as a link so that it can be edited independently and unloaded.

Completing the vicinity model

I added some other major features to the vicinity model and the site model, including

• Northpoint Crossing
• University Housing
• The Stack
• Church Street
• Hurricane Harry’s

My preferred way of doing this requires a few extra steps, but makes a better model. I grabbed some backgrounds from Google maps and the Northpoint Square Web site to allow me to trace the buildings and streets.

Pad objects smooth out the contour lines to produce a level concrete pad at a designated height. Before placing a pad, it is good to know what is the needed elevation of the pad. I used the Annotate menu and its Spot elevation command to figure out the height at the location of the pad. I could then designate the elevation of the finished pad. Revit will dig into the toposurface or elevate above the toposurface as needed to place the pad. The trim and extend commands are very powerful for making a perfectly closed sketch.

With a pad object in place, the conceptual mass for the building is easy. I made “in-place” masses for The Stack and the Northpoint Crossing buildings. Simply sketch them over the image underlay. The trace command can select a chain of lines based on the edge of the pad. This can be extruded by using the Create Form command.

Some of the existing conceptual mass buildings needed to be edited. I opened the Mass family in the family editor. I deleted the old Safeway grocery store. I also added the additional buildings for the University Apartments just to the north of our site by copying the existing mass objects, placing, them, and rotating them.

I also drew Church Street by creating a subregion object on the toposurface. It would be good to draw the rest of Northgate streets, but I have not done that.

When I drew the Northpoint Crossing buildings, I realized that they are some of them are at a slightly different angle. It is possible to rotate a Crop Region in a plan view to get a more convenient angle for horizontal and vertical. This is a very neat trick.

Moving forward

I suggest that you make use of these improved models. Create a Project file or use the one that you are working on. Delete the toposurface and mass objects for the vicinity, and link the vicinity model. Link the site model too. You can edit its toposurface to show the land forms as you design them. At some point you may wish to Bind the linked model into your project. Or you may want to split the toposurface further so that you can manage repairs and increased detail in the existing conditions while still editing the parts that you are allowed to change.

My new files are in the Submittals/Site folder.