I modeled a closed Ohio drive-in for a nonprofit market project using MicroStation for the base file, site3d for grading, OpenRoads for the entrance corridor, Meshy for canopy meshes, and GenAnywhere for unsold context. The pipeline held because each tool had one job and one output label.
What the package had to contain
The Comet Drive-In closed in 2012. The buyer, Barlow Community Market, needed a planning package for a 4,800-square-foot market hall in the old concession building, 36 vendor bays, three workshop buildings, 180 parking stalls, a stormwater basin, and a trail spur.
No new topographic survey existed. I had the boundary, a handful of spot elevations, the county road record, and two days on site.
1. MicroStation: the base file
I built one DGN in Ohio South State Plane, units set to feet, and never edited anything else. The boundary, ditch, building footprint, gravel edge, berms, and the concrete screen base each got a level: SURVEY, DITCH, BLDG_EXIST, PAVE, BERM, SCREEN_BASE.
Everything external arrived as a reference: county road centerline, parcel polygons, orthoimagery, and a utility scan from 2009. References stay read-only, which is the only reason the base file still matches the deed after three weeks of edits.
The same file produced the plan sheets, with inferred levels off for existing conditions and on for the planning exhibit.
2. site3d: grading and the basin
site3d runs inside MicroStation, so the design surface started from the same base geometry. The pad for the market hall came up 1.5 feet to meet the road grade. The basin went to 0.8 acres at 4 feet deep. Between the parking rows I used shallow swales rather than inlets and pipe.
The interesting output was the balance: 3,400 cubic yards cut, 3,100 fill. The 300-yard surplus was moved to the pad instead of hauled off. That changed the project cost sheet, not just the drawing.
I also used site3d to set the parking field at 180 stalls. The old drive-in held 380 cars, and keeping those rows would have painted stalls the market cannot fill.
3. OpenRoads: corridor and culvert
The entrance is the part that touches the county, so it needed corridor-grade geometry. County Road 12 runs at 55 mph with a blind rise north of the site. The new drive is 900 feet, plus a 150-foot turn lane. Sight distance has to reach 425 feet.
OpenRoads built the drive, the taper, the culvert crossing at the west ditch, and the shoulder tie-ins as one corridor. Pavement quantities and pipe length came out of the same model, which is the main reason I used it instead of hand-drafting the section.
4. Meshy: assets you can look at
The board wanted to see the canopy before committing to it. There were no drawings, only photos of tensile structures from other markets. I ran three of those images through Meshy and got textured meshes at three spans.
Scaling was manual: I set each mesh against a known door height in the concession building. The results are visually useful and dimensionally wrong. The fabric sag reads deeper than a real tensioned membrane, and the connection details are suggestion-level. I labeled the meshes as reference geometry and kept them out of the quantity takeoff.
5. GenAnywhere: context for the missing parcel
Eleven acres across County Road 12 have no survey and no recent imagery. GenAnywhere works by drawing a polygon on a map and letting the AI generate terrain and buildings inside it. I outlined that parcel, ran it, and got a farmhouse, two outbuildings, a driveway, and tree cover.
The driveway is invented. A real one exists about 200 feet north. I kept the output anyway, because the point was to see the market against a built edge, not to inventory the neighbor's property. It lives on GEN_CTX with a date stamp and stays out of every area and parking count.
Handoff notes
• Keep a single writable DGN and attach everything else read-only.
• Name levels for what the geometry is, not who made it.
• Record the coordinate system in the file name and the sheet title block.
• Recheck any downloaded or generated surface against at least ten measured points.
• Export the corridor and the grading surface together, or the quantities will not match.
What broke
The downloaded terrain read flatter than the lot is, which I caught with the 11 rod readings. The Meshy canopy was 8 percent too tall until I rescaled it. GenAnywhere added a driveway that does not exist. The OpenRoads corridor had to be rerun when the drive moved.
None of these were surprises by the end. Each one showed up because the tool had a bounded job and a labeled output. The failure mode I worry about is the opposite: one model that looks finished everywhere and quietly mixes survey, inference, and imagination in the same layer.
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