Annotations and measurements: keep the observation
Open Annotations and choose a tool:
| Tool | Gesture | Typical purpose |
|---|---|---|
| Points | Click a surface to place a point annotation. | Mark a location worth returning to. |
| Lines | Click two endpoints; the next click starts a new line. | Capture a particular span, offset, or dimension. |
| Polyline | Click successive vertices, then choose Done. | Follow an edge, route, or sequence of features. |
| Polygon | Click boundary vertices, then choose Done. | Outline a region of interest. |
| Markup | Drag to draw a stroke on the surface; adjust line width as needed. | Highlight a feature for another reviewer. |
A double-click can finish a polyline with at least two vertices or a polygon with at least three. Cancel discards an unfinished measurement. Use Done, Exit, or Stop, as shown for the active tool, to return to navigation.
A good annotation answers a question. For example, instead of tracing every pipe in a scan, mark the two points that establish a critical clearance, or highlight the support that someone must inspect on site. In a rock-slope review, a few annotations can direct attention to a joint, edge, or suspect area. In a corridor survey, they can identify the particular structure or span being discussed.
Place endpoints on actual surfaces, not empty background. The quality of any measurement depends on the source coordinates, units, registration, and points available at the picked locations. In sparse areas, the visible outline is only an approximation of the object between measured points. Shading can make an edge easier to see, but cannot make that edge more accurately surveyed.
When measurements matter: Before using a dimension for an offsite-fabricated component, installation clearance, deformation assessment, or another consequential decision, verify that the dataset and measurement method meet the required tolerances. PurpleGeo helps you investigate the question; the survey's accuracy still sets the limit.