Which node types exist: What do they do?
Nodes are the way sectors define all the structure of the world, both the visible/tangible stuff, and the invisible/intangible things that make stuff work. There are a number of node types for defining objects, be they a static wall, a random prop or an interactive entity. Then there are nodes for defining trigger areas, spawn points, lighting, weather and so on. The nodes carry the information for what mesh to use, which appearance of it, what physical properties to give them and so on. In the sector files there are two lists, the nodes, which define the nodes themselves, and the nodeData which defines where to put them, a single node can be referenced by multiple nodeData entries.
If your just wanting to define new rooms/buildings, it would mostly be static mesh nodes, instanced mesh nodes and decal nodes to define the physical structure, with some collision nodes to make it solid. destructible mesh nodes and entities would then be added for the clutter and interactive bits.
For exteriors, you may need to include proxies because sometimes they're used as a complete replacement for a static mesh node and not just for a low poly counterpart if you want to make something like a shop, you'll need an interior area nodes, community, population spawner nodes if you're working on a quest, you'll need trigger areas, guard areas, and also communities and population spawners
For a full list of node types (as of 2.1), see DocPresto's github
List below is the node types I've found so far while building the blender sector import script.
MinimapDataNode
worldAISpotNode
Usually used within worldCompiledCommunityAreaNode as a spot to spawn an entity.
worldStaticMarkerNode
Used as a scene location point.
worldAcousticSectorNode
worldAmbientAreaNode
worldBendedMeshNode
Used for roads (not implemented in blender import yet)
worldBuildingProxyMeshNode
Proxy mesh for building at further distance. Textures are normally embedded so canonly export with wscript currently.
worldCableMeshNode
Cables, like between utility poles.
worldCollisionNode
partial support, defines 3 types of collision, box, capsule and mesh. Can import the first 2.
worldCompiledCommunityAreaNode_Streamable
Defines a community that controls a group of dynamic entities such as NPCs and vehicles.
worldCompiledSmartObjectsNode
worldDestructibleEntityProxyMeshNode
worldDeviceNode
Essentially the same as worldEntityNode but with the ability define connections to other device entities. Imports as just an entity in blender.
worldEffectNode
Defines effects like smoke.
worldEntityNode
Defines an object defined by an ent file (door, vending machine, fan etc)
worldEntityProxyMeshNode
worldFoliageNode
Puts down lots of small things like boxes, garbage bags, plants. Uses a buffer to define positions that we haven't worked out yet.
worldGINode
worldGIShapeNode
worldGISpaceNode
worldGenericProxyMeshNode
Proxy mesh for objects at distance. Also used for some low poly buildings at a distance without mesh node counterpart.
worldGuardAreaNode
worldInstancedDestructibleMeshNode
as worldInstancedMeshNode but breakable
worldInstancedMeshNode
Instanced copies of a static mesh uses a worldTransformBuffer in the nodeData to define the number of copies and positions of all the copies
worldInstancedOccluderNode
worldInterestingConversationsAreaNode
worldInteriorAreaNode
Defines a trigger area and applied restrictions such as no combat, prevent quests from starting, etc.
worldLightChannelShapeNode
worldLightChannelVolumeNode
worldPerformanceAreaNode
worldPhysicalDestructionNode
worldPopulationSpawnerNode
Spawns entity using TweakDBID. Mainly used for dynamic entities such as vehicles and characters.
worldReflectionProbeNode
worldRoadProxyMeshNode
Road Mesh.
worldRotatingMeshNode
Mesh node with an axis/angle/period defined for rotating
worldStaticDecalNode
Static Decal, nodeData has x,y,z not sure how engine decides what to project to
worldStaticFogVolumeNode
worldStaticMeshNode
Static mesh, nodeData has position data
worldStaticOccluderMeshNode
worldStaticParticleNode
worldStaticSoundEmitterNode
worldTerrainCollisionNode
worldTerrainMeshNode
The ground, textures are embedded, can export with wscript. UVs are messed up for some reason, auto generated for plugin >1.5.1
worldTrafficCompiledNode
worldTriggerAreaNode
Defines an area that can be used by quests to determine when a dynamic entity enters or leaves the area.
worldSmartObjectNode
worldStaticLightNode
Defines a light, either spherical or capsule, can be 360 or spotlight.
worldInteriorMapNode
worldAdvertisementNode
worldMeshNode
worldSplineNode
Defines a path using a bezier spline. Used for NPC walking paths etc. Imported to blender as curve.