---
# System prepended metadata

title: PRo3D Annotations and Measurements

---

# PRo3D Annotations and Measurements

## Annotations Types

| Measurement    | Completes             | Projections                  | Purpose                                                                                    |
| -------------- | --------------------- | ---------------------------- | ------------------------------------------------------------------------------------------ |
| Point          | after 1 point         | `n/a`                        | Determining coordinates of a single point on the surface. Annotating locations.            |
| Line           | after 2 points        | `linear`, `viewpoint`, `sky` | Determining and Annotating the size and scale of features.                                 |
| Polyline       | pressing Enter        | `linear`, `viewpoint`, `sky` | Digitizing geological features such as contacts. Measuring distances along the surface.    |
| Polygon        | closes pressing Enter | `linear`, `viewpoint`, `sky` | Annotating regions.                                                                        |
| DnS (polyline) | pressing Enter        | `linear`, `viewpoint`, `sky` | Determining the orientation of strata via regression plane fitting.                        |
| TT (line)      | after 2 points        | `linear`                     | Determining the true thickness of a stratum with respect to it's orientation (`Dip Angle`) |

### Projections

| Projection | Behavior                                                                                                                                                   |
| ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
| linear     | Linear connection between picked points, effectively no projection applied.                                                                                |
| viewpoint  | Connections between picked points are subsampled and points are projected (raycasted) onto the surface with the camera center being the projection origin. |
| sky        | Connections between picked points are subsampled and points are projected (raycasted) onto the surface along the up-vector of the coordinate system        |

## Measurements

| Measurement         | Unit    | What?                                                                                                                        | Applies to                                         |
| ------------------- | ------- | ---------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------- |
| Height              | meters  | Difference between max and min altitude of all points. Essentially max vertical thickness.                                   | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| Height Delta        | meters  | Difference in altitude between first and last point.                                                                         | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| Avg Altitude        | meters  | Average altitude of all points.                                                                                              | `point`,`line`, `polyline`, `polygon`, `dns`, `tt` |
| Length              | meters  | Distance between first and last point.                                                                                       | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| WayLength           | meters  | Accumulated distance of all line segments.                                                                                   | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| Bearing             | degrees | Orientation of line between first and last point with respect to North (= 0°/360°).                                          | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| Slope               | degrees | Vertical orientation of line between first and last point with respect to horizontal plane (= 0°).                           | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| Vertical Distance   | meters  | Signed vertical distance between first and last point.                                                                       | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| Horizontal Distance | meters  | Horizontal distance between first and last point.                                                                            | `line`, `polyline`, `polygon`, `dns`, `tt`         |
| True Thickness      | meters  | Normal distance between the second point and the (manually specified) dipping plane.                                         | `tt`                                               |
| Vertical Thickness  | meters  | Vertical distance between second point and the (manually specified) dipping plane.                                           | `tt`                                               |
| Dipping Angle       | degrees | Angle between the horizontal plane and the dip, with dip being the direction of maximum inclination on a plane (0°-90°).     | `dns`                                              |
| Dipping Orientation | degrees | Orientation of dip vector in the horizontal plane with respect to North (= 0°/360°).                                         | `dns`                                              |
| Strike Orientation  | degrees | Orientation of strike vector in the horizontal plane with respect to North (= 0°/360°), with strike being orthogonal to dip. | `dns`                                              |

## Viewer GUI

| ![](https://i.imgur.com/BhIUWCa.png) | 
|:--:| 
| *Exemplary length and orientation measurements for a dip-and-strike annotation* |



