Definition

1. A <Feature Face> FF has the following relationship with its associated <Feature Node> instances, if any exist. At any feature topology level, if FF is associated with any <Feature Node> instance FN, then FN shall lie within the external ring of FF, if any, and shall NOT lie within any of the internal rings of FF, if any. Conversely, if a <Feature Node> FN lies within the boundaries of FF, then FN shall be associated with FF. If no <Feature Node> instances lie within its boundaries, FF shall not be associated with any <Feature Node> instances.
2. A <Feature Volume> FV has the following relationship with its associated <Feature Node> instances, if any exist. At any feature topology level, if FV is associated with any <Feature Node> FN, then FN shall lie completely within the external shell of FV, if any, and shall NOT lie within any of the internal shells of FV, if any. Conversely, if a <Feature Node> FN lies within the boundaries of FV, then FN shall be associated with FV. If no <Feature Node> instances lie within its boundaries, FV shall not be associated with any <Feature Node> instances.
3. A <Geometry Face> GF has the following relationship with its associated <Geometry Node> instances, if any. At any geometry topology level, if GF is associated with any <Geometry Node> GN, then GN shall lie within the interior of GF. Conversely, if a <Geometry Node> GN lies within the interior of GF, then GN shall be associated with GF. If no <Geometry Node> lie within its interior, GF shall not be associated with any <Geometry Node> instances.
4. A <Geometry Volume> GV has the following relationship with its associated <Geometry Node> instances, if any exist. At any geometry topology level, if GV is associated with any <Geometry Node> GN, then GN shall lie within the interior of GV. Conversely, if a <Geometry Node> GN lies within the interior of GV, then GN shall be associated with GV. If no <Geometry Node> instances lie within its interior, GV shall not be associated with any <Geometry Node> instances.

Rationale

The associations between <Feature Node> and <Feature Face>, and between <Feature Node> and <Feature Volume>, implement containment relationships. These topological relationships must be consistent, and must be consistent with the geometric representations of these objects.

The associations between <Geometry Node> and <Geometry Face>, and between <Geometry Node> and <Geometry Volume>, implement containment relationships. These topological relationships must be consistent, and must be consistent with the geometric counterparts of these objects.

Example

1. Consider a <Feature Node> N1 that is "floating" within the interior of a <Feature Volume> V1. N1 is contained within V1, and V1 contains N1.

2. Consider a <Geometry Node> N1 that is "floating" within the interior of a <Geometry Volume> V1. N1 is contained within V1, and V1 contains N1.

FAQs

Can a <Feature Node> that is contained within the interior of a <Feature Face> or <Feature Volume> also be connected to one or more <Feature Edge> instances?

Yes. A <Feature Node> that is contained within the interior of a <Feature Face> can also be connected to a <Feature Edge>, as long as that <Feature Edge> does not bound that <Feature Face>. This is only possible within a three-dimensional spatial reference frame. A <Feature Node> that is contained within the interior of a <Feature Volume> can also be connected to a <Feature Edge>, as long as that <Feature Edge> does not bound any of the <Feature Face> instances that in turn bound that <Feature Volume>.

Can a <Geometry Node> that is contained within the interior of a <Geometry Face> or <Geometry Volume> also be connected to one or more <Geometry Edge> instances?

Yes. A <Geometry Node> that is contained within the interior of a <Geometry Face> can also be connected to a <Geometry Edge>, as long as that <Geometry Edge> does not bound that <Geometry Face>. This is only possible within a three-dimensional spatial reference frame. A <Geometry Node> that is contained within the interior of a <Geometry Volume> can also be connected to a <Geometry Edge>, as long as that <Geometry Edge> does not bound any of the <Geometry Face> instances that in turn bound that <Geometry Volume>.