The label is moved from the anchor point towards the camera to be drawn in front of other geometry. The offset was derived from the zoom level, and was not related to the distance between the camera and the anchor point. In a 3D view the offset is usually larger than this distance, moving the label behind the camera. Labels outside the view frustum are silently discarded by the text renderer.
Limit the offset to the smaller of half the distance to the anchor point and the distance to the near plane. The limit is derived from the anchor point and not from the near plane, as the label parts are part of the scene and are used to compute the clipping planes.
Reject anchor point candidates behind the camera. Coordinates behind the camera are mirrored into the viewport by the perspective divide in cvf::Camera::project(), and could be selected as the coordinate closest to the label position.
* 10675 Fix missing intersection line geometry
* Change to list of visible surface intersection lines
* Enable surface intersection band for any intersection
* Show labels for intersection curves in 3D
The polylines are defined in the display coordinate system without Z-scaling. The z-scaling is applied to the visualization parts using Part::setTransform(Transform* transform)
The annotation objects are defined by display coordinates, so apply the Z-scaling to the coordinates.
* Improve naming of surfaces
* Use scaling factor of 1.0 for flat intersection views
Magne Sjaastad