UProceduralMeshComponent has a CreateMeshSection function, but does anyone happen to know what the equivalent would be for a USimpleDynamicMeshComponent or UOctreeDynamicMeshComponent (Not even sure which one to use). Am I supposed to get the FDynamicMesh3 and then use AppendVertices, AppendTriangles individually? Is that correct?
All I want to be able to do is create a simple Triangle , trying to understand how it works by looking at ModelingTools implementation is insanity. Thereās FDynamicMesh, FMeshDescription, Operators, Mechanics, Mesh Editors, Mesh Spatials, Compute Meshes?? etcā¦
If you are looking to create a Component, ie some visible geometry attached to an Actor, then you would use USimpleDynamicMeshComponent (note: in 5.0 USimpleDynamicMeshComponent is renamed UDynamicMeshComponent). And yes you would get the FDynamicMesh3, then call AppendVertex and AppendTriangle, and then call UDynamicMeshComponent::NotifyMeshUpdated().
Alternately you could construct your own FDynamicMesh3 separately and then call UDynamicMeshComponent::SetMesh().
If you have not seen them, it might be helpful to read this article on my website. Itās a bit out-of-date now though:
Basically, FDynamicMesh3 is the data - the actual vertices and triangles - and has nothing to do with Actors/Components/etc. You can use FDynamicMesh3 in pure C++ code to do mesh processing things that are not connected to gameplay. UDynamicMeshComponent is a visible Component where the 3D geometry is defined by a FDynamicMesh3 stored in the Component.
This is similar to UStaticMeshComponent/UStaticMesh, except UStaticMesh doesnāt actually contain the 3D geometry either - UStaticMesh stores the 3D geometry in a FMeshDescription. So FMeshDescription is similar to FDynamicMesh3 in that it is the actual mesh data structure, vs a container for it.
Another way to think about it is UStaticMesh is an Asset that allows multiple UStaticMeshComponent to re-use the same FMeshDescription mesh. There is no asset for FDynamicMesh3 - each UDynamicMeshComponent has itās own FDynamicMesh3 (similar to how UProceduralMeshComponent has itās mesh sections).
Operators, Mechanics, Mesh Editors, Compute Meshes - these are all things that are specific to our modeling tools framework and infrastructure. You would not use them to (eg) display a triangle, you would use them if you want to do mesh editing operations (either computationally or interactively).
āMesh Spatialā generally means an AABBTree for a FDynamicMesh3, or other Mesh. Spatial == Spatial Data Structure. We use this more generic word because we can technically plug in other BVH hierarchies, octrees, etc.
UOctreeDynamicMeshComponent is a variant of USimpleDynamicMeshComponent, so it works the same way (internal FDynamicMesh3 defines what will be rendered). It supports partial updates based on a 3D Octree, but using it is quite complex and I would not recommend it unless you are trying to implement 3D mesh sculpting with dynamic/adaptive remeshing (which is what we use it for).
, trying to understand how it works by looking at ModelingTools implementation is insanity. Thereās FDynamicMesh, FMeshDescription, Operators, Mechanics, Mesh Editors, Mesh Spatials, Compute Meshes?? etcā¦