Node data
The node data contained in the header holds all the metadata for a single node included in the file:
| id: | the id of the sibling. It is unique in the file, but not unique over the entire tree structure. | |
| bbMin: | [min0, min 1, min2] | the smallest corner point of the bounding box. The bounding box is the axis-aligned minimum bounding box of the node's geometry. |
| bbMax: | [max0, max 1, max2] | the largest corner point of the bounding box. The bounding box is the axis-aligned minimum bounding box of the node's geometry. |
| maxScreenDiameter: | dmax | the maximum diameter, in pixels, for which this node should be visible. Once passed this size on screen, the node should be replaced by its children, if it has any. |
| children: | [file_name0, …. ,file_namep] | list of files (relative path) that contain the node's children. |
| resources: | [geometry_ID0, …. ,geometry_IDr] | list of the geometries forming the node. The ID points to a resource in the header's resources collection. |
Note that the node’s resources array can be empty, defining in effect an empty node. Empty nodes are sometimes possible in the 3MX format, and they should be considered. They indicate that the parent geometry has to be made invisible, without it being replaced by another geometry. The absence of children indicates, on the contrary, that the node remains visible always, even if its screen projection surpasses its maxScreenDiameter parameter.