# Class: Geometry
**`Advanced`**
A Geometry is a low-level object that represents the structure of 2D shapes in terms of vertices and attributes.
It's a crucial component for rendering as it describes the shape and format of the data that will go through the shaders.
Essentially, a Geometry object holds the data you'd send to a GPU buffer.
A geometry is basically made of two components:
Attributes: These are essentially arrays that define properties of the vertices like position, color,
texture coordinates, etc. They map directly to attributes in your vertex shaders.
Indices: An optional array that describes how the vertices are connected.
If not provided, vertices will be interpreted in the sequence they're given.
## Example
```ts
const geometry = new Geometry({
attributes: {
aPosition: [ // add some positions
0, 0,
0, 100,
100, 100,
100, 0,
],
aUv: [ // add some uvs
0, 0,
0, 1,
1, 1,
1, 0,
]
}
});
```
## Extends
- `EventEmitter`\<\{ `destroy`: `Geometry`; `unload`: `Geometry`; `update`: `Geometry`; \}\>
## Extended by
- [`BatchGeometry`](rendering.BatchGeometry.html.md)
- [`MeshGeometry`](scene.MeshGeometry.html.md)
## Implements
- [`GPUDataOwner`](rendering.GPUDataOwner.html.md)
- [`GCable`](rendering.GCable.html.md)
## Constructors
### Constructor
> **new Geometry**(`options`): `Geometry`
Create a new instance of a geometry
#### Parameters
##### options
[`GeometryDescriptor`](rendering.GeometryDescriptor.html.md) = `{}`
The options for the geometry.
#### Returns
`Geometry`
#### Overrides
`EventEmitter<{ update: Geometry, destroy: Geometry, unload: Geometry, }>.constructor`
## Properties
### attributes
> `readonly` **attributes**: [`Record`](https://www.typescriptlang.org/docs/handbook/utility-types.html#recordkeys-type)\<`string`, [`Attribute`](rendering.Attribute.html.md)\>
A record of the attributes of the geometry.
***
### autoGarbageCollect
> **autoGarbageCollect**: `boolean` = `true`
If set to true, the resource will be garbage collected automatically when it is not used.
#### Implementation of
[`GCable`](rendering.GCable.html.md).[`autoGarbageCollect`](rendering.GCable.html#autogarbagecollect)
***
### buffers
> `readonly` **buffers**: [`Buffer`](rendering.Buffer.html.md)[]
The buffers that the attributes use
***
### indexBuffer
> **indexBuffer**: [`Buffer`](rendering.Buffer.html.md)
The index buffer of the geometry
***
### indexCount
> **indexCount**: `number` = `0`
The number of indices to draw, or `0` to draw the whole index buffer.
Set this when a geometry only covers a prefix of an index buffer it shares with others - a
pool of identical quads, say, where one buffer holds the six indices per quad for the largest
batch and each geometry draws as many quads as it currently holds. A `size` passed to the
draw call still wins, and a geometry with no index buffer ignores this entirely
([Geometry.vertexCount](#vertexcount) drives those). Read at draw time only, so changing it never
re-uploads or re-lays-out anything.
#### Default
```ts
0
```
***
### instanceCount
> **instanceCount**: `number` = `1`
the instance count of the geometry to draw
***
### topology
> **topology**: [`Topology`](rendering.Topology.html.md)
The topology of the geometry.
***
### uid
> `readonly` **uid**: `number`
The unique id of the geometry.
## Accessors
### bounds
#### Get Signature
> **get** **bounds**(): [`Bounds`](rendering.Bounds.html.md)
Returns the bounds of the geometry.
##### Returns
[`Bounds`](rendering.Bounds.html.md)
***
### vertexCount
#### Get Signature
> **get** **vertexCount**(): `number`
The number of vertices in this geometry, derived from the first non-instanced attribute.
The value is cached and only recalculated when the geometry's buffers or attributes change.
##### Returns
`number`
## Methods
### addAttribute()
> **addAttribute**(`name`, `attributeOption`): `void`
Adds an attribute to the geometry.
#### Parameters
##### name
`string`
The name of the attribute to add.
##### attributeOption
[`AttributeOption`](rendering.AttributeOption.html.md)
The attribute option to add.
#### Returns
`void`
***
### addIndex()
> **addIndex**(`indexBuffer`): `void`
Adds an index buffer to the geometry.
#### Parameters
##### indexBuffer
The index buffer to add. Can be a Buffer, TypedArray, or an array of numbers.
`number`[] | [`Buffer`](rendering.Buffer.html.md) | [`TypedArray`](rendering.TypedArray.html.md)
#### Returns
`void`
***
### destroy()
> **destroy**(`destroyBuffers`): `void`
destroys the geometry.
#### Parameters
##### destroyBuffers
`boolean` = `false`
destroy the buffers associated with this geometry
#### Returns
`void`
***
### getAttribute()
> **getAttribute**(`id`): [`Attribute`](rendering.Attribute.html.md)
Returns the requested attribute.
#### Parameters
##### id
`string`
The name of the attribute required
#### Returns
[`Attribute`](rendering.Attribute.html.md)
- The attribute requested.
***
### getBuffer()
> **getBuffer**(`id`): [`Buffer`](rendering.Buffer.html.md)
Returns the requested buffer.
#### Parameters
##### id
`string`
The name of the buffer required.
#### Returns
[`Buffer`](rendering.Buffer.html.md)
- The buffer requested.
***
### getIndex()
> **getIndex**(): [`Buffer`](rendering.Buffer.html.md)
Returns the index buffer
#### Returns
[`Buffer`](rendering.Buffer.html.md)
- The index buffer.
***
### ~~getSize()~~
> **getSize**(): `number`
Used to figure out how many vertices there are in this geometry
#### Returns
`number`
the number of vertices in the geometry
#### Deprecated
since 8.20.0, use [Geometry.vertexCount](#vertexcount) instead
***
### unload()
> **unload**(): `void`
Unloads the geometry from the GPU.
#### Returns
`void`
#### Implementation of
[`GCable`](rendering.GCable.html.md).[`unload`](rendering.GCable.html#unload)