Class InstanceStates

Per-instance material states for instanced meshes (trees, rocks, buildings, props): four floats per instance (wetness, snow, burn, damage) in an InstancedBufferAttribute, read in the shader through InstanceStates.node.

Example

const states = new InstanceStates(trees.count)
applyMaterialStatesTo(barkMaterial, { ...states.node(), wetness: field.node().wetness })
states.set(12, { burn: 1 })                        // tree 12 burnt down
states.sampleField(field, treePositions)           // pick up burn scars and storm damage

Index

Constructors

constructor

new InstanceStates(
count: number,
initial?: Partial<MaterialStates>,
): InstanceStates
Creates count instances, all starting at initial (default all 0).
Parameters
- count: number
- initial: Partial<MaterialStates> = {}
Returns InstanceStates
- Defined in weathering/src/instance-states.ts:39

Properties

`Readonly`array

array: Float32Array

The states, 4 floats per instance (wetness, snow, burn, damage).

`Readonly`attribute

attribute: InstancedBufferAttribute

The GPU attribute (item size 4).

`Readonly`count

count: number

Number of instances.

Methods

add

add(i: number, channel: StateChannel, amount: number): this
Adds amount to one state of instance i (clamped to 0…1).
Parameters
- i: number
- channel: StateChannel
- amount: number
Returns this
- Defined in weathering/src/instance-states.ts:67

attach

attach(geometry: BufferGeometry, name?: string): this
Adds the attribute to a geometry under name (for InstancedBufferGeometry setups).
Parameters
- geometry: BufferGeometry
- name: string = 'instanceStates'
Returns this
- Defined in weathering/src/instance-states.ts:112

decay

decay(dt: number, rates: Partial<MaterialStates>): this
Relaxes states towards 0 at rates per second (e.g. drying: { wetness: 1 / 7200 }).
Parameters
- dt: number
- rates: Partial<MaterialStates>
Returns this
- Defined in weathering/src/instance-states.ts:84

get

get(i: number, out?: MaterialStates): MaterialStates
States of instance i.
Parameters
- i: number
- out: MaterialStates = ...
Returns MaterialStates
- Defined in weathering/src/instance-states.ts:47

node

node(): StateNodes
The four states as TSL nodes for the current instance. Works with InstancedMesh and instanced geometry.

Returns StateNodes
- Defined in weathering/src/instance-states.ts:118

sampleField

sampleField(
    field: StateField,
    positions: ArrayLike<number>,
    options?: Partial<SampleFieldOptions>,
): this
Copies states from a StateField at each instance position (frame coordinates, x and z read from positions with stride), so trees pick up fire scars, storm damage, wetness and snow.
Parameters
- field: StateField
- positions: ArrayLike<number>
- options: Partial<SampleFieldOptions> = {}
Returns this
- Defined in weathering/src/instance-states.ts:97

set

set(i: number, values: Partial<MaterialStates>): this
Sets states of instance i (clamped to 0…1); missing channels are kept.
Parameters
- i: number
- values: Partial<MaterialStates>
Returns this
- Defined in weathering/src/instance-states.ts:58

setAll

setAll(values: Partial<MaterialStates>): this
Sets the given channels on every instance.
Parameters
- values: Partial<MaterialStates>
Returns this
- Defined in weathering/src/instance-states.ts:74

value

value(i: number, channel: StateChannel): number
One state of instance i.
Parameters
- i: number
- channel: StateChannel
Returns number
- Defined in weathering/src/instance-states.ts:53

Class InstanceStates

Example

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

Returns InstanceStates

Properties

Readonlyarray

Readonlyattribute

Readonlycount

Methods

add

Parameters

Returns this

attach

Parameters

Returns this

decay

Parameters

Returns this

get

Parameters

Returns MaterialStates

node

Returns StateNodes

sampleField

Parameters

Returns this

set

Parameters

Returns this

setAll

Parameters

Returns this

value

Parameters

Returns number

Settings

On This Page

`Readonly`array

`Readonly`attribute

`Readonly`count