Control the 3D camera

In a 3D view, the camera that you look through is called the eye. You can set the eye from code with the eye_controls parameter of Spatial3DView, which takes an EyeControls3D blueprint archetype (see eye_controls).

Set the eye position and look target

import rerun as rr
import rerun.blueprint as rrb

rr.init("rerun_example_eye_controls", spawn=True)

rr.log("world/points", rr.Points3D([[0, 0, 0], [1, 0, 0], [0, 1, 0], [0, 0, 1]], radii=0.05))

rr.send_blueprint(
    rrb.Spatial3DView(
        origin="/world",
        eye_controls=rrb.EyeControls3D(
            position=[4.0, -4.0, 3.0],
            look_target=[0.0, 0.0, 0.0],
            eye_up=[0.0, 0.0, 1.0],
        ),
    )
)

EyeControls3D has these fields:

Field	Meaning
`kind`	`rrb.Eye3DKind.Orbital` (default) or `rrb.Eye3DKind.FirstPerson`.
`position`	The position of the eye.
`look_target`	The point that the eye looks at. For an orbital eye, this is also the point it orbits around.
`eye_up`	The up axis of the eye, in world space. Defaults to the up axis of the scene, or +Z if there is none.
`speed`	Translation speed when you move with the WASDQE keys.
`tracking_entity`	An entity that the eye follows. See below.
`spin_speed`	Spin the eye around the up axis at this speed. Defaults to 0 (no spinning).

The scene up axis comes from ViewCoordinates. For example, log rr.ViewCoordinates.RIGHT_HAND_Z_UP as static data on the view's origin entity to make +Z the up axis.

The blueprint sets the eye when the Viewer receives it. After that, the user can move the eye freely. Send the blueprint again to move the eye back.

Orbital or first-person controls

Orbital: the eye rotates around look_target. Scroll zooms toward and away from it.
FirstPerson: the eye rotates around its own position, like in a first-person game. Use WASD and QE to move.

rrb.Spatial3DView(
    origin="/world",
    eye_controls=rrb.EyeControls3D(kind=rrb.Eye3DKind.FirstPerson, speed=20.0),
)

You can also switch between the two in the Viewer: select the view and change the eye kind in the selection panel.

Follow an entity

Set tracking_entity to make the eye follow an entity as it moves:

rrb.Spatial3DView(
    origin="/world",
    eye_controls=rrb.EyeControls3D(tracking_entity="/world/robot"),
)

If the tracked entity is a camera (an entity with a Pinhole), the eye takes over the pose of that camera, so you see the scene through it.

In the Viewer, you can start tracking an entity with Alt + double-click on it, or with "Set as eye tracked" in its context menu. Double-click an entity to focus on it, and double-click the background to reset the eye.

Limitations

There is currently no way to:

lock the eye, so that the user cannot move it,
limit how far the user can zoom in or out.

See missing features.