VolumeMapper

Source (.js)Source (.d.ts)

Methods

applyShaderReplacements

Apply the shader replacements a renderable declares under its OpenGL view specific properties.

Argument	Type	Required	Description
shaders	IShaderSources	Yes	The shader sources, edited in place.
viewSpec		Yes	The OpenGL view specific properties of the renderable.
pre	Boolean	No	Apply the replacements marked replaceFirst.

buildBufferObjects

Build the scalar, color, opacity and label outline textures, and the vertex buffer of the box the volume is ray cast through.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

buildPass

Drop the z-buffer texture captured by a previous traversal.

buildShaders

Assemble the shader sources, applying the user replacements and the mapper's own substitutions.

Argument	Type	Required	Description
shaders	IShaderSources	Yes	The shader sources, edited in place.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

extend

Method used to decorate a given object (publicAPI+model) with vtkOpenGLVolumeMapper characteristics.

Argument	Type	Required	Description
publicAPI		Yes	object on which methods will be bounds (public)
model		Yes	object on which data structure will be bounds (protected)
initialValues	IOpenGLVolumeMapperInitialValues	No	(default: {})

getClippingPlaneShaderParameters

Set the clipping plane uniforms of the shader program.

Argument	Type	Required	Description
cellBO		Yes	The OpenGL helper carrying the shader program.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

getContext

Get the WebGL context this mapper renders with.

getCurrentSampleDistance

Get the sample distance to ray cast with, which is the renderable's sample distance scaled by its interaction factor while the interactor animates.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.

getNeedToRebuildBufferObjects

Whether the textures and the vertex buffer are out of date.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

getNeedToRebuildShaders

Whether the shader program has to be rebuilt for the given helper.

Argument	Type	Required	Description
cellBO		Yes	The OpenGL helper carrying the shader program.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

getRenderTargetOffset

Get the lower left corner of the viewport this mapper renders into.

getRenderTargetSize

Get the width and height of the target this mapper renders into, which is the reduced offscreen size while the volume is rendered at a lower resolution.

getReplacedShaderTemplate

Fill in the shader template, letting the renderable's OpenGL view specific properties override any of the three shader sources.

Argument	Type	Required	Description
shaders	IShaderSources	Yes	The shader sources, edited in place.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

getShaderTemplate

Fill in the shader sources with the default volume shader template.

Argument	Type	Required	Description
shaders	IShaderSources	Yes	The shader sources, edited in place.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

newInstance

Method used to create a new instance of vtkOpenGLVolumeMapper.

Argument	Type	Required	Description
initialValues	IOpenGLVolumeMapperInitialValues	No	for pre-setting some of its content

opaqueZBufferPass

Capture the z-buffer texture of the pass, so that the volume can be mixed with the opaque geometry.

Argument	Type	Required	Description
prepass	Boolean	Yes	Whether the traversal is on its way down.
renderPass	vtkForwardPass	Yes	The pass holding the z-buffer texture.

releaseGraphicsResources

Release the framebuffers, textures and vertex buffers of this mapper.

renderPiece

Render the volume for the given renderer and actor.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

renderPieceDraw

Activate the textures, update the shaders and draw the box the volume is ray cast through.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

renderPieceFinish

Blit the reduced-resolution offscreen result back onto the render target and update the frame timing that drives the resolution.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

renderPieceStart

Pick the render resolution from the recent frame times, bind the offscreen framebuffer when one is needed, and bring the buffer objects up to date.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

replaceShaderValues

Substitute the mapper's own declarations and implementation into the shader sources.

Argument	Type	Required	Description
shaders	IShaderSources	Yes	The shader sources, edited in place.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

setCameraShaderParameters

Set the camera uniforms of the shader program.

Argument	Type	Required	Description
cellBO		Yes	The OpenGL helper carrying the shader program.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

setContext

Set the WebGL context this mapper renders with.

Argument	Type	Required	Description
context		Yes	The WebGL context.

setMapperShaderParameters

Set the texture and geometry uniforms of the shader program.

Argument	Type	Required	Description
cellBO		Yes	The OpenGL helper carrying the shader program.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

setPropertyShaderParameters

Set the volume property uniforms of the shader program, including the transfer function ranges and the lighting.

Argument	Type	Required	Description
cellBO		Yes	The OpenGL helper carrying the shader program.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

updateBufferObjects

Rebuild the buffer objects when they are out of date.

Argument	Type	Required	Description
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

updateShaders

Make the helper's shader program current, rebuilding it when needed, and push the mapper, camera and property uniforms.

Argument	Type	Required	Description
cellBO		Yes	The OpenGL helper carrying the shader program.
ren	vtkRenderer	Yes	The renderer.
actor	vtkVolume	Yes	The volume being rendered.

volumePass

Resolve the ancestors this mapper renders with and render the volume.

Argument	Type	Required	Description
prepass	Boolean	Yes	Whether the traversal is on its way down.
renderPass	vtkRenderPass	Yes	The render pass being traversed.

zBufferPass

Capture the z-buffer texture of the pass, so that the volume can be mixed with the opaque geometry.

Argument	Type	Required	Description
prepass	Boolean	Yes	Whether the traversal is on its way down.
renderPass	vtkForwardPass	Yes	The pass holding the z-buffer texture.