When switching to a USD camera, the orbit pivot was set from
GfCamera::GetFocusDistance() which is a depth-of-field attribute
that defaults to 5 scene units regardless of scene scale.
InitCameraNavigation() now computes the scene bounding box centroid,
projects it onto the camera view ray to get a proper orbit distance,
and calls SetFocalPoint/SetDist to place the pivot correctly.
Added SetDist() setter on ViewportCamera to support this.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
indigo
ee1b750f8c