GPS Model Layer and Surface Naming Standards
Updated: Jun 17
Quantum Land Design names every layer and surface in a machine control model by a fixed convention: plain-English names on 2D lines, a "-3D" prefix on every 3D line, short abbreviations for surfaces (FG, RG, SG, SAN, STM, WTR), and the revision date appended whenever something changes. An operator or foreman should read a layer name and know exactly what it is without opening the plans.
We have built this system through over 20,000 models delivered to contractors.
We've learned to keep it simple:
A field crew reads "-3D-Storm" and knows it is the 3D storm line, not a 2D reference line.
A revised surface labeled "FG-3-8-25" can never be confused with the version it replaced. The date is in the name.
Layer colors tell you exactly what line you are grading to at a glance.
Lines (linework, polylines)
2D Lines
Labeled in plain English.
Layers added as needed per project.
All lines are 2D unless noted.
3D Lines
Always carry the “-3D" prefix
Examples: "-3D-Storm" or "-3D-Centerline"
Projects with 2D and 3D lines will always have both line types.
3D utility model surfaces will always have a matching 3D line.
Revisions
Line changes during revisions will be appended with the date of the revision.
Example : "-3D-Storm-3-8-25"
Surfaces (TTM, TN3, XML, TIN)
Standard Surface Abbreviations
FG = Finish Grade
RG = Rough Grade
SG = Subgrade
SAN = Sanitary Sewer
STM = Storm Sewer
WTR = Water Line
Additional 3D surfaces (structural features, underground detention systems, and the like) will be named as appropriate for your project.
3D utility surfaces are set to plan elevations, typically flowline. Always refer to plans to verify.
Revisions
Surfaces changed during revisions will be appended with the date of the revision.
Example: "FG-3-8-25" or "STM-12-14-25"
When you are ready for a new model built to our consistent standards
Common Question About Layers and Surfaces
What does the "-3D" prefix mean on a machine control layer?
It marks a 3D line. 3D lines contain elevation data along with their horizontal location. Every 3D line in a Quantum model starts with "-3D" (for example "-3D-Centerline"), so crews can identify 3D linework with vertical data from 2D reference linework at a glance.
What do FG, RG, and SG stand for in a GPS grading model?
FG is Finish Grade, RG is Rough Grade, SG is Subgrade. Subgrade models are rarely necessary but they can be required for some projects. These are the standard surface abbreviations Quantum uses across every machine control model.
How are model revisions labeled?
The revision date is appended to the name. A finish grade surface revised on March 8, 2025 becomes "FG-3-8-25". A storm line revised the same day becomes "-3D-Storm-3-8-25". The version is readable in the name itself.
What elevation are 3D utility surfaces set to?
Plan elevation, typically flowline. Always check the plans or ask your contact at Quantum to confirm before you build.