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@novorender/api / RenderContext

Class: RenderContext

Defined in: @novorender/src/core3d/context.ts:66

The view specific context for rendering and picking.

Remarks​

A render context describes a view into which a RenderState can be rendered. It is tightly bound to a HTML canvas and WebGL2RenderingContext. Consequently, it will be disposed if the gl context is lost and recreated when the gl context is restored.

The render context must be initialized with an array of render modules. Unused modules may be removed and custom ones inserted here. Ordering the modules correctly is important as they are rendered in order. The TonemapModule should be last, as it will copy the HDR render buffers into the output canvas to make things visible.

Features such as async picking and shader linking requires poll to be called at regular intervals, e.g. at the start of each frame. Otherwise the promises will never be resolved.

Accessors​

height​

Get Signature​

get height(): number;

Defined in: @novorender/src/core3d/context.ts:432

Return the current pixel height of the drawing buffer.

Returns​

number

width​

Get Signature​

get width(): number;

Defined in: @novorender/src/core3d/context.ts:427

Return the current pixel width of the drawing buffer.

Returns​

number

Methods​

clearPickBuffers()​

clearPickBuffers(): void;

Defined in: @novorender/src/core3d/context.ts:938

Returns​

void

dispose()​

dispose(): void;

Defined in: @novorender/src/core3d/context.ts:401

Dispose of the GPU resources used by this context, effectively destroying it and freeing up memory.

Returns​

void

Remarks​

Calling this method is optional as the garbage collection of the underlying WebGL render context will do the same thing. This may take some time, however, so calling this function is recommended if you plan to create a new context shortly thereafter.

getDeviations()​

getDeviations(): Promise<DeviationSample[]>;

Defined in: @novorender/src/core3d/context.ts:1010

scan the pick buffer for deviation values

Returns​

Promise<DeviationSample[]>

Return pixel coordinates and deviation values for any deviation on screen

getLinearDepths()​

getLinearDepths(pick): IterableIterator<number>;

Defined in: @novorender/src/core3d/context.ts:999

Parameters​

ParameterType
pickUint32Array

Returns​

IterableIterator<number>

getNonParametricEdgeDirAtPoints()​

getNonParametricEdgeDirAtPoints(points, tolerance): Promise<undefined | (null | ReadonlyVec3)[]>;

Defined in: @novorender/src/core3d/context.ts:1642

Parameters​

ParameterType
pointsobject[]
tolerancenumber

Returns​

Promise<undefined | (null | ReadonlyVec3)[]>

getOutlines()​

getOutlines(): Promise<OutlineSample[]>;

Defined in: @novorender/src/core3d/context.ts:1066

scan the pick buffer for pixels from clipping outline

Returns​

Promise<OutlineSample[]>

Return pixel coordinates and world position for any clipping outline on screen

hasStateChanged()​

hasStateChanged(state): boolean;

Defined in: @novorender/src/core3d/context.ts:554

Helper function to check for changes in render state.

Parameters​

ParameterTypeDescription
statePartial<DerivedRenderState>The parts of the render state to check for changes.

Returns​

boolean

True if any of the specified parts has changed since last frame.

Remarks​

Since the render state is immutable, any changes will automatically trickle up to the container object as well. Thus, this function does a shallow strict equality of the parts of the renderstate specified in the state parameter.

Example​

Example of how to check for changes in either camera or output render state.

const {camera, output} = renderState;
if(renderContext.hasStateChanged({camera, output})) {
  // update related GPU state here...
}

init()​

init(modules?, showWatermark?): Promise<void>;

Defined in: @novorender/src/core3d/context.ts:344

Initialize render context with specified render modules.

Parameters​

ParameterTypeDefault valueDescription
modules?readonly RenderModule[]undefined-
showWatermark?booleantruefalse filters out the watermark module regardless if the modules are provided or not.

Returns​

Promise<void>

Remarks​

The default/built-in render modules can be retrieved using createDefaultModules. These will be used if no modules are specified. Developers may introduce their own render modules here. Note that the order of the modules matters, as this is the order by which they will be rendered.

isContextLost()​

isContextLost(): boolean;

Defined in: @novorender/src/core3d/context.ts:477

Query whether the underlying WebGL render context is currently lost.

Returns​

boolean

Remarks​

This could occur when too many resources are allocated or when browser window is dragged across screens. Loss and restoration of WebGL contexts is supported by this API automatically.

isPickBuffersRendered()​

isPickBuffersRendered(): boolean;

Defined in: @novorender/src/core3d/context.ts:448

Query if pick buffers are rendered. Means pick buffer is rendered, but not yet copied to CPU.

Returns​

boolean

Remarks​

This could be useful for optimistic/non-async picking.

isPickBuffersUpToDate()​

isPickBuffersUpToDate(): boolean;

Defined in: @novorender/src/core3d/context.ts:456

Query if pick buffers are up to date. Means it's valid and it represents current (latest) frame.

Returns​

boolean

Remarks​

This could be useful for optimistic/non-async picking.

isPickBuffersValid()​

isPickBuffersValid(): boolean;

Defined in: @novorender/src/core3d/context.ts:440

Query if pick buffers are valid. Valid means that the buffer is filled (not just arrays with zeros) and represents correct resolution.

Returns​

boolean

Remarks​

This could be useful for optimistic/non-async picking.

isSceneResolved()​

isSceneResolved(): boolean;

Defined in: @novorender/src/core3d/context.ts:463

The scene is considered resolved when all currently split nodes are done downloading.

Returns​

boolean

makeProgramAsync()​

makeProgramAsync(resourceBin, params): Promise<WebGLProgram>;

Defined in: @novorender/src/core3d/context.ts:574

Compile WebGL/GLSL shader program asynchronously.

Parameters​

ParameterType
resourceBinResourceBin
paramsAsyncProgramParams

Returns​

Promise<WebGLProgram>

pick()​

pick(
   x, 
   y, 
options?): Promise<PickSample[]>;

Defined in: @novorender/src/core3d/context.ts:1585

Pick information about underlying object and geometry.

Parameters​

ParameterTypeDescription
xnumberCenter x coordinate in CSS pixels.
ynumberCenter y coordinate in CSS pixels.
options?PickOptionsMore details of pick operation.

Returns​

Promise<PickSample[]>

A set of pick samples of the specified sample disc.

poll()​

poll(): void;

Defined in: @novorender/src/core3d/context.ts:694

Poll the status of WebGL pick fences and timers and resolve associated promises when possible.

Returns​

void

render()​

render(state): Promise<RenderStatistics>;

Defined in: @novorender/src/core3d/context.ts:746

Render a new frame using the specified render state.

Parameters​

ParameterTypeDescription
stateRenderStateAn object describing what the frame should look like.

Returns​

Promise<RenderStatistics>

A promise to the performance related statistics involved in rendering this frame.

renderPickBuffers()​

renderPickBuffers(): void;

Defined in: @novorender/src/core3d/context.ts:948

Returns​

void

resourceBin()​

resourceBin(name): ResourceBin;

Defined in: @novorender/src/core3d/context.ts:569

Create a new named resource bin.

Parameters​

ParameterType
namestring

Returns​

ResourceBin

setPolygonFillMode()​

setPolygonFillMode(mode): void;

Defined in: @novorender/src/core3d/context.ts:1634

Parameters​

ParameterType
mode"FILL" | "LINE"

Returns​

void

updateIBLTextures()​

updateIBLTextures(params): void;

Defined in: @novorender/src/core3d/context.ts:509

Explicitly update WebGL IBL textures from specified parameters.

Parameters​

ParameterType
params| null | { diffuse: TextureParamsCubeUncompressed; specular: TextureParamsCubeUncompressedMipMapped; }

Returns​

void

updateUniformBuffer()​

updateUniformBuffer(uniformBuffer, proxy): void;

Defined in: @novorender/src/core3d/context.ts:493

Helper function to update WebGL uniform buffer from proxies.

Parameters​

ParameterType
uniformBufferWebGLBuffer
proxyUniformsProxy

Returns​

void

nextFrame()​

static nextFrame(context): Promise<number>;

Defined in: @novorender/src/core3d/context.ts:725

Wait for the next frame to be ready for rendering.

Parameters​

ParameterTypeDescription
contextundefined | RenderContextrender context to wait for, if any.

Returns​

Promise<number>

Remarks​

Use this function instead of requestAnimationFrame()!

Properties​

buffers​

buffers: RenderBuffers;

Defined in: @novorender/src/core3d/context.ts:173

WebGL render and pick buffers

Remarks​

Note that these buffers will be recreated whenever the RenderState.output size changes.

cameraUniforms​

readonly cameraUniforms: WebGLBuffer;

Defined in: @novorender/src/core3d/context.ts:132

WebGL uniform buffer for camera related uniforms.

canvas​

readonly canvas: HTMLCanvasElement;

Defined in: @novorender/src/core3d/context.ts:204

The HTML canvas used for this context.

changed​

changed: boolean = true;

Defined in: @novorender/src/core3d/context.ts:166

Set to true to force a re-render when state not contained in RenderState has changed, e.g. download complete etc.

clippingUniforms​

readonly clippingUniforms: WebGLBuffer;

Defined in: @novorender/src/core3d/context.ts:134

WebGL uniform buffer for clipping related uniforms.

commonChunk​

readonly commonChunk: string;

Defined in: @novorender/src/core3d/context.ts:70

WebGL common GLSL code header used across shaders.

currentState​

currentState: undefined | DerivedRenderState;

Defined in: @novorender/src/core3d/context.ts:163

RenderState used to make the newest state available during render.

defaultIBLTextureParams​

readonly defaultIBLTextureParams: TextureParamsCubeUncompressed;

Defined in: @novorender/src/core3d/context.ts:72

WebGL basic fallback IBL textures to use while loading proper IBL textures.

deviceProfile​

readonly deviceProfile: DeviceProfile;

Defined in: @novorender/src/core3d/context.ts:202

The device profile use for this context.

gl​

readonly gl: WebGL2RenderingContext;

Defined in: @novorender/src/core3d/context.ts:68

WebGL2 render context associated with this object.

iblTextures​

iblTextures: object;

Defined in: @novorender/src/core3d/context.ts:181

WebGL textures used for image based lighting (IBL).

default​

readonly default: boolean;

True if these are the default IBL textures.

diffuse​

readonly diffuse: WebGLTexture;

WebGL cubemap texture containing the irradiance/diffuse values of current IBL environment.

numMipMaps​

readonly numMipMaps: number;

mip maps in current specular texture.

specular​

readonly specular: WebGLTexture;

WebGL cubemap texture containing the radiance/specular values of current IBL environment.

Remarks​

Note that these buffers will be changed by the background module when download of the specified RenderState.background.url IBL textures completes.

The process to create the textures are similar to that of https://github.com/KhronosGroup/glTF-IBL-Sampler/

loaderWorker​

readonly loaderWorker: Worker;

Defined in: @novorender/src/core3d/context.ts:193

lut_ggx​

readonly lut_ggx: WebGLTexture;

Defined in: @novorender/src/core3d/context.ts:138

WebGL GGX/PBR shading lookup table texture.

lutGGXImage​

readonly lutGGXImage: ImageBitmap;

Defined in: @novorender/src/core3d/context.ts:206

The lutGGX file.

outlineRenderers​

outlineRenderers: WeakMap<ReadonlyVec4, OutlineRenderer>;

Defined in: @novorender/src/core3d/context.ts:153

outlineUniforms​

readonly outlineUniforms: WebGLBuffer;

Defined in: @novorender/src/core3d/context.ts:136

WebGL uniform buffer for outline related uniforms.

prevState​

prevState: undefined | DerivedRenderState;

Defined in: @novorender/src/core3d/context.ts:159

RenderState used to render the previous frame, if any.

samplerEnvMip​

readonly samplerEnvMip: WebGLSampler;

Defined in: @novorender/src/core3d/context.ts:140

WebGL Sampler used to sample mip mapped IBL texture trilinear.

samplerMip​

readonly samplerMip: WebGLSampler;

Defined in: @novorender/src/core3d/context.ts:142

WebGL Sampler used to sample mipmapped texture trilinear.

samplerMipRepeat​

readonly samplerMipRepeat: WebGLSampler;

Defined in: @novorender/src/core3d/context.ts:144

WebGL Sampler used to sample mipmapped texture trilinear repeating UV.

samplerSingle​

readonly samplerSingle: WebGLSampler;

Defined in: @novorender/src/core3d/context.ts:146

WebGL Sampler used to sample other, non-mipmapped IBL textures bilinear.

usePrepass​

readonly usePrepass: false = false;

Defined in: @novorender/src/core3d/context.ts:119