Label

Provides a logical and graphic connection between an HTML label and a scene object. This node draws a line between the object's local origin and the center of the label. The line is updated every animation frame. The label is defined in HTML as a child of <scene>. A label is identified by the id attribute. The connection is between the tags with the specified id for the label and the scene object.

The label must have the [inherited] class 'sceneLabels'. It is allowed to have multiple block tags with that class or the individual labels can be collected under one or more tags (e.g., <div>) with that class. Each label may be individually styled as needed for the display. If the class xseen-screen-drag is present on the label, then that element can be repositioned in the scene canvas.

All labels are positioned with normal CSS stylying within the scene canvas. Each label is positioned absolute so full control is given to the developer as to layout. The labels appear in the scene by virtue of them being inside the canvas. They are always positioned at the near clipping plane, so there is no other scene element in front (between the label and the rendered display) of them.

The label tag draws a line from the object's local origin to the center of the label as currently positioned in 3D space (Remember that local Z is always the near clipping plane distance.) If the object has displayed local Z less than the near clipping plane distance, then the line may not be drawn. The line is recalculated each animation frame so it continuously tracks object, camera, and label motion.

A label can move if it has the class xseen-screen-drag and the user drags it within the canvas. It can also move if labeltype has the value initialize. This causes the system to compute the initial offset in screen space from the label to the projection of the object's center. That relationship is maintained throughout the display independent of the object or camera motion. Using the value of initialze overrides the ability to independently move the label.

Use of label in stereo camera mode may not work as expected.