publicRenderingEngine
Implements
Index
Constructors
Properties
Methods
Constructors
constructor
Parameters
optionalid: string
Returns RenderingEngine
Properties
publichasBeenDestroyed
A flag which tells if the renderingEngine has been destroyed or not
readonlyid
Unique identifier for renderingEngine
readonlyoffScreenCanvasContainer
publicoffscreenMultiRenderWindow
Methods
_debugRender
Returns void
_downloadOffScreenCanvas
Returns void
publicdestroy
destroy the rendering engine. It will remove all the viewports and, if the rendering engine is using the GPU, it will also destroy the GPU resources.
Returns void
publicdisableElement
Disables the requested viewportId from the rendering engine:
- It removes the viewport from the the list of viewports
- remove the renderer from the offScreen render window if using vtk.js driven rendering pipeline
- resetting the viewport to remove the canvas attributes and canvas data
- resize the offScreen appropriately (if using vtk.js driven rendering pipeline)
Parameters
viewportId: string
viewport Id
Returns void
publicenableElement
Enables the requested viewport and add it to the viewports. It will properly create the Stack viewport or Volume viewport:
- Checks if the viewport is defined already, if yes, remove it first
- Checks if the viewport is using a custom rendering pipeline, if no, it calculates a new offscreen canvas with the new requested viewport
- Adds the viewport
renderingEngine.enableElement({
viewportId: viewportId,
type: ViewportType.ORTHOGRAPHIC,
element,
defaultOptions: {
orientation: Enums.OrientationAxis.AXIAL,
background: [1, 0, 1],
},
})Parameters
viewportInputEntry: PublicViewportInput
viewport specifications
Returns void
publicfillCanvasWithBackgroundColor
Fill the canvas with the background color
Parameters
canvas: HTMLCanvasElement
The canvas element to draw on.
backgroundColor: [number, number, number]
An array of three numbers between 0 and 1 that specify the red, green, and blue values of the background color.
Returns void
publicgetStackViewports
Filters all the available viewports and return the stack viewports
Returns default[]
stack viewports registered on the rendering Engine
publicgetVideoViewports
Filters all the available viewports and return the stack viewports
Returns default[]
stack viewports registered on the rendering Engine
publicgetViewport
Returns the viewport by Id
Parameters
viewportId: string
Returns IViewport
viewport
publicgetViewports
getViewports Returns an array of all
Viewports on theRenderingEngineinstance.Returns IViewport[]
Array of viewports
publicgetVolumeViewports
Return all the viewports that are volume viewports
Returns default[]
An array of VolumeViewport objects.
publicrender
Renders all viewports on the next animation frame.
Returns void
publicrenderFrameOfReference
Renders any viewports viewing the given Frame Of Reference.
Parameters
FrameOfReferenceUID: string
The unique identifier of the Frame Of Reference.
Returns void
publicrenderViewport
Renders only a specific
Viewporton the next animation frame.Parameters
viewportId: string
The Id of the viewport.
Returns void
publicrenderViewports
Renders the provided Viewport IDs.
Parameters
viewportIds: string[]
Returns void
publicresize
Resizes the offscreen viewport and recalculates translations to on screen canvases. It is up to the parent app to call the resize of the on-screen canvas changes. This is left as an app level concern as one might want to debounce the changes, or the like.
Parameters
immediate: boolean = true
Whether all of the viewports should be rendered immediately.
keepCamera: boolean = true
Whether to keep the camera for other viewports while resizing the offscreen canvas
Returns void
publicsetViewports
It takes an array of viewport input objects including element, viewportId, type and defaultOptions. It will add the viewport to the rendering engine and enables them.
renderingEngine.setViewports([
{
viewportId: axialViewportId,
type: ViewportType.ORTHOGRAPHIC,
element: document.getElementById('axialDiv'),
defaultOptions: {
orientation: Enums.OrientationAxis.AXIAL,
},
},
{
viewportId: sagittalViewportId,
type: ViewportType.ORTHOGRAPHIC,
element: document.getElementById('sagittalDiv'),
defaultOptions: {
orientation: Enums.OrientationAxis.SAGITTAL,
},
},
{
viewportId: customOrientationViewportId,
type: ViewportType.ORTHOGRAPHIC,
element: document.getElementById('customOrientationDiv'),
defaultOptions: {
orientation: { viewPlaneNormal: [0, 0, 1], viewUp: [0, 1, 0] },
},
},
])Parameters
publicViewportInputEntries: PublicViewportInput[]
Returns void
A RenderingEngine takes care of the full pipeline of creating viewports and rendering them on a large offscreen canvas and transmitting this data back to the screen. This allows us to leverage the power of vtk.js whilst only using one WebGL context for the processing, and allowing us to share texture memory across on-screen viewports that show the same data.
Instantiating a rendering engine:
There are various ways you can trigger a render on viewports. The simplest is to call
render()on the rendering engine; however, it will trigger a render on all viewports. A more efficient way to do this is to callrenderViewports([viewportId])on the rendering engine to trigger a render on a specific viewport(s). Each viewport also has a.rendermethod which can be used to trigger a render on that viewport.Rendering engine uses
detect-gpuexternal library to detect if GPU is available and it has minimum requirement to be able to render a volume with vtk.js. If GPU is not available RenderingEngine will throw an error if you try to render a volume; however, for StackViewports it is capable of falling back to CPU rendering for Stack images.By default RenderingEngine will use vtk.js enabled pipeline for rendering viewports, however, if a custom rendering pipeline is specified by a custom viewport, it will be used instead. We use this custom pipeline to render a StackViewport on CPU using Cornerstone-legacy cpu rendering pipeline.