Fit a camera to a whole scene

Computes a camera that frames the contents of a scene (see scene), i.e. its meshes together with the line layers that contribute to the scene bounds (see line_layer, parameter affects_bounds). Use this instead of camera_auto when the camera has to consider something else than a mesh: a scene that contains only line layers (e.g. a tractogram or a connectome without a brain surface) is framed by those lines, and decorational layers (affects_bounds = FALSE) are ignored.

Usage

camera_fit_scene(
  scene,
  direction = c(0, 0, -1),
  up = c(0, 1, 0),
  fov = 45,
  margin = 1.1,
  projection = c("perspective", "orthographic")
)

Arguments

scene

A scene descriptor list, see scene().

direction

Length-3 view direction, from the camera towards the scene (default c(0, 0, -1), i.e. looking along -Z).

up

Length-3 up vector (default c(0, 1, 0)).

fov

Vertical field of view in degrees (default 45).

margin

Scale factor applied to the fitted distance; values above 1 leave a margin around the content (default 1.1).

projection

Projection type, "perspective" (default) or "orthographic".

Value

A camera list (see camera()) with class "scimesh_camera".

Details

The camera is placed on the line from the center of the bounding box along direction, at a distance that makes the content fit into the field of view, exactly like camera_auto does it for a mesh.

See also

camera_auto for meshes, scene, scene_set_line_affects_bounds

Examples

# A scene without any mesh is framed by its lines.
line <- line_layer(matrix(c(0, 0, 0), ncol = 3), matrix(c(2, 0, 0), ncol = 3))
sc <- scene(list(), lines = line)
cam <- camera_fit_scene(sc, direction = c(0, 0, -1))