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Documentation / scene / DualDepthPeelingOIT

Class: DualDepthPeelingOIT ​

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:39

Dual depth peeling OIT renderer.

Remarks ​

This implementation follows the official dual depth peeling pass structure: an initialization pass writes the nearest/farthest transparent depth pair, then each peel pass ping-pongs the depth pair while accumulating front and back colors.

It requires MRT, per-target blending, min/max blend equations and blendable floating-point color targets. If those capabilities are missing, supportDevice() returns false and the transparent pass falls back to sorted alpha blending.

Extends ​

Constructors ​

Constructor ​

new DualDepthPeelingOIT(numPeels?): DualDepthPeelingOIT

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:62

Creates an instance of DualDepthPeelingOIT.

Parameters ​

numPeels? ​

number = 8

Number of peel iterations after the initialization pass.

Returns ​

DualDepthPeelingOIT

Overrides ​

OIT.constructor

Properties ​

type ​

readonly static type: "ddp" = 'ddp'

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:41

Type name of DualDepthPeelingOIT

Accessors ​

disposed ​

Get Signature ​

get disposed(): boolean

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

Returns ​

boolean

Inherited from ​

OIT.disposed


numPeels ​

Get Signature ​

get numPeels(): number

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:75

Number of front/back peel iterations after the initialization pass.

Returns ​

number

Set Signature ​

set numPeels(val): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:78

Parameters ​
val ​

number

Returns ​

void


uniformTag ​

Get Signature ​

get uniformTag(): number

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

Returns ​

number

Inherited from ​

OIT.uniformTag

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 ​

OIT.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 ​

OIT.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 ​

OIT.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 ​

OIT.dispatchEvent


dispose() ​

dispose(): void

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

Returns ​

void

Inherited from ​

OIT.dispose


supportDeviceCaps() ​

static supportDeviceCaps(deviceType, caps): boolean

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:89

Checks whether dual depth peeling can run with a capability snapshot.

Parameters ​

deviceType ​

string

The device type.

caps ​

DeviceCaps

The device capabilities.

Returns ​

boolean

True if dual depth peeling is supported.


getType() ​

getType(): string

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:110

Returns the type of the renderer.

Returns ​

string

The type of the renderer.

Overrides ​

OIT.getType


supportDevice() ​

supportDevice(deviceType): boolean

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:117

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.

Overrides ​

OIT.supportDevice


wantsPremultipliedAlpha() ​

wantsPremultipliedAlpha(): boolean

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:129

Whether this OIT algorithm wants pre-multiplied alpha

Returns ​

boolean

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

Overrides ​

OIT.wantsPremultipliedAlpha


wantsAdditiveLightPassAlpha() ​

wantsAdditiveLightPassAlpha(): boolean

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:136

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.

Overrides ​

OIT.wantsAdditiveLightPassAlpha


begin() ​

begin(ctx): number

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:143

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.

Overrides ​

OIT.begin


end() ​

end(ctx): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:156

Ends rendering the transparent objects.

Parameters ​

ctx ​

DrawContext

The draw context.

Returns ​

void

Overrides ​

OIT.end


beginPass() ​

beginPass(ctx, pass): boolean

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:170

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.

Overrides ​

OIT.beginPass


endPass() ​

endPass(ctx, _pass): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:198

Ends rendering for the given pass.

Parameters ​

ctx ​

DrawContext

The draw context.

_pass ​

number

The pass number.

Returns ​

void

Overrides ​

OIT.endPass


setupFragmentOutput() ​

setupFragmentOutput(scope): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:205

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.

Overrides ​

OIT.setupFragmentOutput


outputFragmentColor() ​

outputFragmentColor(scope, color, ctx): boolean

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:218

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.

Overrides ​

OIT.outputFragmentColor


applyUniforms() ​

applyUniforms(_ctx, bindGroup): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:280

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

Overrides ​

OIT.applyUniforms


calculateHash() ​

calculateHash(): string

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:289

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.

Overrides ​

OIT.calculateHash


setRenderStates() ​

setRenderStates(rs): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:296

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

Overrides ​

OIT.setRenderStates


onDispose() ​

protected onDispose(): void

Defined in: libs/scene/src/render/dualdepthpeeling_oit.ts:447

Returns ​

void

Overrides ​

OIT.onDispose


uniformChanged() ​

uniformChanged(): void

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

Returns ​

void

Inherited from ​

OIT.uniformChanged

Released under the MIT License.