> For the complete documentation index, see [llms.txt](https://docs.oserosuite.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.oserosuite.com/technical-notes/unreal-engine-notes/water-plugin/water-meshes.md).

# Water Meshes

* **UWaterSubsystem**
  * Handles all the intersections and such through **FWaterBodyManager**
* **AWaterZoneActor**
  * Actor that holds the meshes
  * Adds all the new actors and uses them to separate the rendering into the transition pieces and such
  * A big volume covering the level
* **UWaterMeshComponent**
  * UWaterMeshComponent::PostEditComponentMove
    * Marks the mesh as needs rebuild (bNeedsRebuild) via the AWaterZoneActor Owner of *this* component
  * UWaterMeshComponent::Update: Gets called on tick by the UWaterSubsystem
    * If bNeedsRebuild, calls UWaterMeshComponent::RebuildWaterMesh
  * UWaterMeshComponent::RebuildWaterMesh
    * Builds the geometry for this water mesh component
    * Gets the Dynamic Material Instance from the Water Body (UWaterBodyComponent::CreateOrUpdateWaterMID)
      * Also calls UWaterBodyComponent::SetDynamicParametersOnMID which sets global values from the UWaterSubsystem and UWaterBodyComponent and AWaterZone
      * Also gets the River to Lake and River to Ocean Transition Material Instances from the Water Body Component (which are again Dynamic Material Instances)
    * Uses a **HActor** as a hit proxy for the mesh in the viewport
    * Water Body Component also stores collision components
      * River: SplineMeshComponents
    * **FWaterQuadTree** stores the mesh data
* **FWaterMeshSceneProxy**
  * The primitive that is drawn in the scene
  * Created by the WaterMeshComponent
* **TWaterVertexFactory**
  * Constucts and handles the RHI data including the vertex buffer
* **FWaterMeshVertexBuffer**
  * Vertex buffer for drawing the water mesh
* **TWaterInstanceDataBuffers**
  * Collection of vertex buffers used by the factory