Site and Drainage Grading Overview - Why Terrains

Why Terrains?

Terrains are the 3D surfaces created from 3D Elements.  Why do we need Terrains?

• Contours
  • Quality Control / Debugging
    • Contours can emphasize minor elevation differences/deviations
• Draping Other Elements
• Components - 3D spatial elements
  • Material Layers and Quantities
• Volumes
• Hydrology- there are a lot of tools that require terrains.

Contours are unmatched in conveying detailed information about surfaces - subtle changes in gradient can easily be spotted with contours.

For example, which looks easier to debug: without or with contours: