Follower

Source (.js)Source (.d.ts)

Introduction

vtkFollower is a subclass of Actor that always faces the camera.

You must set the camera before use. This class will update the matrix such that the follower always faces the camera. Sepcifically the y axis will up up, the Z axes will point to the camera and the x axis will point to the right. You may need to rotate, scale, position the follower to get your data oriented propoerly for this convention.

If useViewUp is set then instea dof using the camera's view up the follow's viewUp will be used. This is usefull in cases where you want up to be locked independent of the camera. This is typically the case for VR or AR annotations where the headset may tilt but text should continue to be relative to a constant view up vector.

Methods

computeMatrix

Generate the matrix based on ivars.

extend

Method use to decorate a given object (publicAPI+model) with vtkFollower characteristics.

Argument	Type	Required	Description
publicAPI		Yes	object on which methods will be bounds (public)
model		Yes	object on which data structure will be bounds (protected)
initialValues	IFollowerInitialValues	No	(default: {})

getCamera

Get the camera to follow.

getUseViewUp

Check whether the view up vector is used.

getViewUp

Get the view up vector.

getViewUpByReference

Get a reference to the view up vector.

newInstance

Method use to create a new instance of vtkFollower

Argument	Type	Required	Description
initialValues	IFollowerInitialValues	No	for pre-setting some of its content

setCamera

Set the camera to follow. If this is not set, then the follower won't know what to follow.

Argument	Type	Required	Description
camera	vtkCamera	Yes

setUseViewUp

Set whether to use the view up vector.

Argument	Type	Required	Description
useViewUp	Boolean	Yes

setViewUp

Set the viewUp vector.

Argument	Type	Required	Description
viewUp	Array[Number]	Yes	The view up vector.