Skip to content

Documentation / scene / OIT

Abstract Class: OIT

Defined in: libs/scene/src/render/oit.ts:23

Abstract class for order-independent transparency renderers.

Order-independent transparency (OIT) renderers allow for rendering of transparent objects in any order, regardless of their depth.

This abstract class defines the common interface for all OIT renderers. Specific implementations of OIT renderers should extend this class and provide concrete implementations for the abstract methods.

Extends

  • Disposable

Extended by

Constructors

Constructor

new OIT(): OIT

Defined in: libs/scene/src/render/oit.ts:25

Returns

OIT

Overrides

Disposable.constructor

Accessors

disposed

Get Signature

get disposed(): boolean

Defined in: libs/base/dist/index.d.ts:6107

Returns

boolean

Inherited from

Disposable.disposed


uniformTag

Get Signature

get uniformTag(): number

Defined in: libs/scene/src/render/oit.ts:29

Returns

number

Methods

on()

on<K>(type, listener, context?): void

Defined in: libs/base/dist/index.d.ts:630

IEventTarget.on

Type Parameters

K

K extends "dispose"

Parameters

type

K

listener

EventListener<{ dispose: []; }, K>

context?

unknown

Returns

void

Inherited from

Disposable.on


once()

once<K>(type, listener, context?): void

Defined in: libs/base/dist/index.d.ts:634

IEventTarget.once

Type Parameters

K

K extends "dispose"

Parameters

type

K

listener

EventListener<{ dispose: []; }, K>

context?

unknown

Returns

void

Inherited from

Disposable.once


off()

off<K>(type, listener?, context?): void

Defined in: libs/base/dist/index.d.ts:638

IEventTarget.off

Type Parameters

K

K extends "dispose"

Parameters

type

K

listener?

EventListener<{ dispose: []; }>

context?

unknown

Returns

void

Inherited from

Disposable.off


dispatchEvent()

dispatchEvent<K>(type, ...args): void

Defined in: libs/base/dist/index.d.ts:642

IEventTarget.dispatchEvent

Type Parameters

K

K extends "dispose"

Parameters

type

K

args

...object[K]

Returns

void

Inherited from

Disposable.dispatchEvent


dispose()

dispose(): void

Defined in: libs/base/dist/index.d.ts:6108

Returns

void

Inherited from

Disposable.dispose


onDispose()

protected onDispose(): void

Defined in: libs/base/dist/index.d.ts:6109

Returns

void

Inherited from

Disposable.onDispose


uniformChanged()

uniformChanged(): void

Defined in: libs/scene/src/render/oit.ts:32

Returns

void


getType()

abstract getType(): string

Defined in: libs/scene/src/render/oit.ts:40

Returns the type of the renderer.

Returns

string

The type of the renderer.


supportDevice()

abstract supportDevice(deviceType): boolean

Defined in: libs/scene/src/render/oit.ts:47

Checks whether the renderer supports the given device type.

Parameters

deviceType

string

The device type.

Returns

boolean

True if the renderer supports the device type, false otherwise.


wantsPremultipliedAlpha()

abstract wantsPremultipliedAlpha(): boolean

Defined in: libs/scene/src/render/oit.ts:53

Whether this OIT algorithm wants pre-multiplied alpha

Returns

boolean

True if the OIT wants pre-multiplied alpha, false otherwise


begin()

abstract begin(ctx): number

Defined in: libs/scene/src/render/oit.ts:67

Begins rendering the transparent objects.

Parameters

ctx

DrawContext

The draw context.

Returns

number

The number of passes required for rendering.

Remarks

Contract: the caller (the transparent scene pass) must have explicitly bound the transparent scene target framebuffer before calling begin(), beginPass() or endPass(). Implementations may redirect rendering to internal buffers, but must composite into that bound target and restore it before returning.


end()

abstract end(ctx): void

Defined in: libs/scene/src/render/oit.ts:73

Ends rendering the transparent objects.

Parameters

ctx

DrawContext

The draw context.

Returns

void


beginPass()

abstract beginPass(ctx, pass): boolean

Defined in: libs/scene/src/render/oit.ts:81

Begins rendering for the given pass.

Parameters

ctx

DrawContext

The draw context.

pass

number

The pass number.

Returns

boolean

True if the transparent objects should be rendered, false otherwise.


endPass()

abstract endPass(ctx, pass): void

Defined in: libs/scene/src/render/oit.ts:88

Ends rendering for the given pass.

Parameters

ctx

DrawContext

The draw context.

pass

number

The pass number.

Returns

void


setupFragmentOutput()

abstract setupFragmentOutput(scope): void

Defined in: libs/scene/src/render/oit.ts:97

Sets up the fragment output.

Parameters

scope

PBGlobalScope

The global shader scope.

Returns

void

Remarks

This method declares necessary uniform variables for OIT rendering and injects it into the object's material.


outputFragmentColor()

abstract outputFragmentColor(scope, color, ctx): boolean

Defined in: libs/scene/src/render/oit.ts:107

Do the fragment color output.

Parameters

scope

PBInsideFunctionScope

The global shader scope.

color

PBShaderExp

The calculated fragment color.

ctx

DrawContext

Returns

boolean

Remarks

This method outputs the calculated fragment color for OIT rendering and injects it into the object's material.


applyUniforms()

abstract applyUniforms(ctx, bindGroup): void

Defined in: libs/scene/src/render/oit.ts:116

Applies the uniforms for the given draw context and bind group.

This function will be called when ever the transparent material will upload uniform variables.

Parameters

ctx

DrawContext

The draw context.

bindGroup

BindGroup

The bind group.

Returns

void


wantsAdditiveLightPassAlpha()

abstract wantsAdditiveLightPassAlpha(): boolean

Defined in: libs/scene/src/render/oit.ts:124

Whether additive light passes should keep the material alpha before OIT output.

Returns

boolean

Remarks

Some OIT algorithms need the original material alpha to weight additive light color, but write zero alpha to their accumulation targets so transmittance is not counted twice.


calculateHash()

abstract calculateHash(): string

Defined in: libs/scene/src/render/oit.ts:133

Calculates the hash of the renderer.

Returns

string

The hash of the renderer.

Remarks

When this hash value was changed, material shader will be forced recreate.


setRenderStates()

abstract setRenderStates(rs): void

Defined in: libs/scene/src/render/oit.ts:141

Sets the render states for the renderer.

This function will be called when the transparent object will be rendered.

Parameters

rs

RenderStateSet

The render states.

Returns

void

Released under the MIT License.