The fence on the bluff property sat about four feet off the deed line, and nobody could agree which one was right. I had two tabs open and a client meeting in the morning. One was TopoExport, the other GenAnywhere. Both take a box on a map and hand back a site model. By the end of the week I had a simple split in my head: one is for arguments, the other is for drawings.
The Same Box, Two Different Promises
The interface hardly matters. You find the site, drag a rectangle, and wait. What differs is the promise underneath. GenAnywhere promises an interpretation: an AI model looks at the area you selected and generates a 3D version of it. TopoExport promises a transcription: it pulls mapped layers — parcels, buildings, roads, water, trees, contours — and converts them into files you can open elsewhere.
An interpretation is wonderful when the question is open; a transcription is wonderful when it is closed. Most projects contain both kinds of questions, which is why I stopped looking for a winner.
GenAnywhere Is a Very Good First Draft
I framed the bluff lot and a block of neighbors, and the model came back quickly. Rooflines, garages, the way the street bent around the ravine — it read convincingly at a glance. I used it to show the client how much of her view came from the empty lot next door.
Then I looked closely. The back edge of the property had softened into the slope. A shed had become part of the main house. When I regenerated the same area, the geometry shifted a little, like a sketch redrawn from memory. Nothing was wildly wrong. Nothing was quite right either.
TopoExport Is a Pile of Records You Can Check
TopoExport gave me something I could argue with. The parcel polygon, the building footprint, the road centerline, and the contours all arrived as separate things, in formats I could use: DXF and DWG for CAD, PDF and SVG for exhibits, OBJ and IFC and STL for solid geometry. Native output for Revit and Rhino cut out a translation step. The 3D export included a terrain mesh and building volumes with roof forms, so the ravine behind the house was actually a ravine.
It was not perfect. The tree layer was a few years old and still showed a hedge that had been pulled out. The far side of the block had thinner data than the near side. That is the deal with public records: they are honest about what they know, and silent about what they do not.
The Deed Line Is a Warning for Both
Here is the part that took me a while to accept. Neither tool settles a boundary. A parcel layer is a mapped representation, not a legal survey, and an AI generated model is even further from the deed. When the fence question came up, I used the exports to frame the conversation and then told the client, plainly, that she needed a surveyor. The tools made the problem visible. They did not make it disappear.
Two Failures Worth Remembering
The first was drift. Two runs of the AI model on the same box produced two slightly different edge conditions, which is fine for a mood board and useless for a dimension string.
The second was age. Data layers have dates, and nobody reads them until something looks off. I now check the vintage of the tree and building layers before I trust either.
How I Use Them Now
I start with TopoExport and set the ground truth: property line, street, existing buildings, slope. Then I open GenAnywhere and make three or four rough futures, mostly to see what the site wants to become. The AI versions live in a folder called "options" and never get measured. When one option survives, I redraw it on the exported base.
What Accurate Means to Me Now
I used to think accuracy was a number, like being within six inches. Now I think it is traceability. Can I say where this line came from, who published it, and when? TopoExport mostly can. GenAnywhere mostly cannot, and it is not pretending to. That is why I keep both, and why I no longer get annoyed when one behaves exactly like the thing it is.
