3. Move Around the Site

A large point cloud is easier to understand when you choose the camera for the job. PurpleGeo provides three different ways of navigating because finding a location, walking through it, and examining one object are different tasks.

Map: find the area first

Map is a top-down orthographic view, without perspective foreshortening.

• Left-drag to pan.
• Scroll to zoom around the pointer.
• Right-drag vertically to zoom.
• Double-click an area to centre it and zoom closer.

Map is the quickest way to regain orientation on a large site. It is especially useful for locating a building, a particular part of a road, or a survey tile before switching to 3D.

A reliable approach is to locate the area in Map, zoom in, then switch to a 3D camera. You can always return to Map if you lose track of where you are.

Fly: move through the site

Fly is a first-person camera. Left-drag to look around, and use the movement keys below to travel. It is convenient with a trackpad or mouse without a middle button.

Fly is useful when you need to follow a route: moving along a road, tracing a powerline corridor, approaching a bridge from below, or inspecting a long industrial installation. The question is less what does this object look like from all sides? and more what will I encounter as I move through this place?

Movement follows the camera orientation: forward goes where you are looking, and Q/E move along the camera's up/down direction. Looking steeply up or down changes how movement feels.

Rotate & Inspect: examine a feature

Rotate & Inspect is the orbit camera, best used with a three-button mouse.

• Left-drag to rotate around a surface point near the cursor. A pivot sphere shows the rotation centre.
• Middle-drag to pan.
• Right-drag to turn the camera in place.
• Scroll to move towards or away from the area under the pointer.
• Double-click a surface to move closer to it.

The pivot is what makes this different from Fly. You are moving around a feature rather than simply turning your head. Start a drag over the rock face, machine, pole, wall, or other feature you want to inspect.

If there is no usable surface at the cursor, the camera may reuse a recent pivot or choose a fallback. Movement keys also work in this mode. Mouse zoom in 3D moves the camera through space; it does not merely enlarge the image.

A useful sequence: Find a retaining wall in Map, switch to Rotate & Inspect, orbit around the wall to understand its shape, then cut a Cross Section perpendicular to it. That often gives you the necessary context more quickly than trying to study the whole structure from one viewpoint.

Keyboard reference

These controls apply while navigating, not while typing into a text field.

For camera movement, Ctrl means the Control key, including on macOS; do not substitute Command. Layer multi-selection supports both Ctrl-click and Command-click.

Touch controls and finding your way back

On iPad, a single-finger drag follows the active camera's main drag action. Two-finger gestures support pan and pinch zoom where that camera mode allows them. The on-screen joystick provides movement in Fly mode. Double-tap has the same navigation purpose as double-click when no editing tool consumes the gesture.

If you lose your place, switch to Map or use the camera's home/reset control. F is useful for framing selected layers. The minimap, where available, provides another reference for orientation while working in 3D.

If dragging starts drawing instead of moving the camera, finish or switch off the active Cross Section or annotation tool. Navigation and drawing sometimes use the same mouse gesture, so the active tool matters.