Geometry

A geometry library for the AEC sector.

Motivations

This geometry kernel is a part of a couple projects that I am undertaking concurrently to this endeavour. One is an MArchProf thesis (starting 2027). The other is yet-to-see-the-light-of-day... 👀

Now I am very aware of the Dunning-Kruger effect when making this statement and am happy to be wrong:

As far as I know, no geometry kernel exists for the AEC that matches the semantics I am trying to achieve (see below).

My requirements:

• I want a core geometry kernel that defines the mathematical properties and relationships between abstract and simple geometry types. This library should be extensible to add more types as I see fit, but should have the core principle that it is abstracted away from the world of AEC and all the dogma that comes with this industry.
• I want an abstract "entities" layer, which uses the core geometry kernel to start to define AEC-related entities; this may be a beam, a wall, a floor, etc.
• I want to capture the types defined in the core geometry kernel to be defined as JsonSchema. This is for a number of reasons.
• I want to be able to serialize and deserialize these two layers and their types to JSON as well as other file formats. For now, JSON is fine.
• I want to be able to convert these two layers and their types to other SDK types, such as Speckle or IFC. Speckle is fine for now (I don't like IFC).
• I want all of this to live outside of an proprietary CAD/BIM software.
• I want this to be open-source, for the greater good.
• I want the architecture of the library to be extensible and comprehensible.

As far as I know, something with all of these requirements does not exist. Please tell me if I am wrong.

The semantics

Core Geometry Layer

To me, there is pure geometry; the kind we get taught in school. The kind that Euclid talked about, and that we have mathematical equations for. A vector, a line, a BRep, a mesh, the list goes on.

This kind of geometry lives in a world free of the dogma of AEC. It could be used in graphics, a computation, a query, and is abstract. It uses equations and properties to define a piece of geometry; it doesn't have metadata.

The geometry layer is mutable - a lot of these types will be value types (.NET structs), and so will be mutable by nature.

I intend on building an immutable, composable layer over top of these types as a way to have composable operations (for those Grasshopper lovers out there).

Descriptors a.k.a metadata

Why not call it metadata?

To get away from the dogma of the name metadata. Everyone has opinions on what metadata is.

What are descriptors?

Descriptors are used to describe an Entity. This could be its name, its description, an Id, a set of geometry, a colour, a product sku, the list goes on. They are the things that if you saw this entity on the street, you'd use them to describe it.

Entities

Finally, we have entities.

Entities are a combination of descriptors. An entity may have a name, a colour, an Id, a list of geometry, the list goes on. Essentially, it is a collection of descriptors.

An entity is not geometry. I know that can be a hard thing to grasp. Geometry is an an abstract concept that doesn't exist. Geometry is merely a descriptor of an entity.

An entity's display value can render on a screen as a mesh, sure, but that would come through determining if an entity has the quality is renderable (in .NET, that could be IRenderable) and then querying the underlying display value a.k.a, a combination of the entity's material and geometry (converted to a mesh, of course).

Simply put: an entity is a thing where one of its qualities is a list of abstract geometries; it is not attributed geometry.

Overview on semantics

Here is a little diagram to explain the semantics as they're in my head

flowchart LR

A[Geometry]
B[Name]
C[Colour]
D[Supplier]
E[Embodied Co2]
G[...]
F[Beam]
subgraph Descriptors
A
B
C
D
E
G
end

Descriptors --> F

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Library Structure

The library is structured as such:

• Core: A pure, unbiased, undogmatic abstract mathematical geometry layer
• Entities.Core: A home for the abstractions that define entities.
• Entities.%: A layer where entities start to be described as a set of descriptors. The % represents a particular sub-sector of AEC. This could be "Structural" for structural engineering, or "Sustainability" for sustainability. The list goes on. Feel free to add it.
• Core.Schemas: A collection of schemas that have been defined for the types as defined in Core. If you are defining your own types at any point, you are encouraged to publish these schemas. Please see %schema-library-link-goes-here% for info on Schemas.
• *.Speckle: Converters for converting to and from Speckle types. Speckle is awesome. You should try it out if you haven't already.

Finally...

This is meant to be fun.

Am I insane? Maybe. Will I learn a sh*t tonne on the way. Absolutely. Will this project, die a slow, painful death? Only time will tell!

I know this is a big undertaking. This is a small-ish part to play in a bigger vision for the AEC industry.

More to come on that later...