com.openinventor.inventor

Class SoOffscreenRenderArea

java.lang.Object

com.openinventor.inventor.Inventor

com.openinventor.inventor.SoOffscreenRenderArea

All Implemented Interfaces:

SafeDisposable, SiRenderArea, SiRenderAreaAntialiasing, SiRenderAreaTransparency

public class SoOffscreenRenderArea
extends Inventor
implements SiRenderArea, SiRenderAreaAntialiasing, SiRenderAreaTransparency, SafeDisposable

Render to an off-screen buffer for printing or generating textures. This class is used to render a scene graph and to write the the result into a file or a buffer.

This is not a screen capture class. The specified scene graph is rendered to generate an image. This allows generation of images larger (higher resolution) than the user's screen and/or using different (e.g. higher quality) rendering parameters. The offscreen rendering may take more or less time than the same rendering on screen.

The renderer can render very large images because it is able to render the scene as multiple "tiles" and assemble the tiles into a complete image. Of course this requires multiple render traversals of the specified scene graph (one for each tile).

Rendering a "snapshot":

Your application may want to render the same image that the user sees on the screen. There are several things to consider. First, the scene graph given to the renderer must include the camera node that the viewer is using. If the application allows the viewer to create a camera automatically, the scene graph returned by the viewer's getSceneGraph() method does not include the camera. It's always safer to get the SoSceneManager object then get the scene graph. Second, some rendering options are set on the viewer object, not in the scene graph. These options, which include background color and transparency mode, must be explicitly queried from the viewer and set on the renderer object.

Notes & Limitations:

• The default tile size is set to the maximum viewport size supported by the hardware (GL_MAX_VIEWPORT_DIMS), which means that tiling will be enabled only when large viewport sizes are requested.
• When tiling is enabled, the elements SoViewportRegionElement, SoLogicalViewportElement and SoModifyViewVolumeElement are set with different values for each tile, which means that scenegraphs that manage sub-viewports will need to take these elements into account in order for the final rendering to be correct.
• Maximum output image size is 25000 x 25000 pixels.

  EXAMPLE

 SoOffscreenRenderArea myOffscreen = new SoOffscreenRenderArea();
 // Set the size of the output
 myOffscreen.setSize( new SbVec2i32( 15360, 8640 ) );
 // Set the sceneGraph to render
 myOffscreen.setSceneGraph(mySceneGraph);
 // If you want to render by tile
 if ( tileRendering )
   myOffscreen.setTile(new SbVec2i32(3840, 2160), 2);
 
 // Specify the color of the clear performed before rendering, here clear with white color
 myOffscreen.setClearColor( new SbColorRGBA(1.f, 1.f, 1.f, 1.f) );
 
 // Save the render as a PNG file
 // Specify that we also want to write the alpha component
 myOffscreen.renderToFile("result.png", SoOffscreenRenderArea.OutputFormats.RGBA);
 
 // Save the render in a buffer
 myOffscreen.renderToBuffer(myBuffer);

Since:

Open Inventor 10.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SoOffscreenRenderArea.EventArg Event that can be sent to the application for each tile rendered.
static class	SoOffscreenRenderArea.OutputFormats Describes the format of the rendering output.

Nested classes/interfaces inherited from class com.openinventor.inventor.Inventor

Inventor.ConstructorCommand

Nested classes/interfaces inherited from interface com.openinventor.inventor.viewercomponents.SiRenderArea

SiRenderArea.ClearPolicies, SiRenderArea.RenderEventArg, SiRenderArea.RenderStatus

Field Summary

Fields

Modifier and Type	Field and Description
SbEventHandler<SoOffscreenRenderArea.EventArg>	onTileRendered Event raised when a tile has been rendered.

Fields inherited from class com.openinventor.inventor.Inventor

VERBOSE_LEVEL, ZeroHandle

Constructor Summary

Constructors

Constructor and Description
SoOffscreenRenderArea() Default constructor.
SoOffscreenRenderArea(SoGLContext glContex) Builds a new offscreen render area by sharing the given SoGlContext.
SoOffscreenRenderArea(SoRenderAreaCore renderAreaCore) Builds a new offscreen render area by using the given renderAreaCore.

Method Summary

Modifier and Type	Method and Description
boolean	dispose() Explicitly call this method to force object to dispose its unmanaged resources.
SoSceneManager.AntialiasingModes	getAntialiasingMode()
float	getAntialiasingQuality()
SbColorRGBA	getClearColor()
float	getClearDepth()
SiRenderArea.ClearPolicies	getClearPolicy()
SoGLRenderAction	getGLRenderAction() Returns the render action used for rendering.
static SbVec2i32	getMaxTileSize() Gets the maximum subimage (tile) size for rendering.
int	getNumEdgePixels()
SoNode	getSceneGraph()
SoSceneManager	getSceneManager() Returns the encapsulated scene manager.
SbVec2i32	getSize()
SbVec2i32	getTileSize()
SoGLRenderAction.TransparencyTypes	getTransparencyType()
SbViewportRegion	getViewportRegion()
boolean	isDisposable() Returns a boolean flag which indicates if it is safe to call SafeDisposable.dispose() on the object.
SbEventHandler<SiRenderArea.RenderEventArg>	onStartRender() Returns the event handler that raises when a new render starts.
SiRenderArea.RenderStatus	render() Calling the render() method is useless and does nothing.
boolean	renderToBuffer(SoBufferObject buffer) Calls renderToBuffer(buffer, SoOffscreenRenderArea.OutputFormats.valueOf( SoOffscreenRenderArea.OutputFormats.RGB.getValue() )).
boolean	renderToBuffer(SoBufferObject buffer, SoOffscreenRenderArea.OutputFormats outputFormat) Render the given scene graph and save the result in the given buffer.
boolean	renderToFile(java.lang.String filename) Calls renderToFile(filename, SoOffscreenRenderArea.OutputFormats.valueOf( SoOffscreenRenderArea.OutputFormats.RGB.getValue() )).
boolean	renderToFile(java.lang.String filename, SoOffscreenRenderArea.OutputFormats outputFormat) Render the given scene graph and save the result in the given file.
void	setAntialiasingMode(SoSceneManager.AntialiasingModes mode) Define the antialiasing mode.
void	setAntialiasingQuality(float quality) Define the antialiasing quality value.
void	setClearColor(SbColorRGBA color) Defines the RGBA value used when the color buffer is cleared.
void	setClearDepth(float depth) Defines the depth value used when the depth buffer is cleared.
void	setClearPolicy(SiRenderArea.ClearPolicies policy) Defines the color buffer and depth buffer clear policy.
void	setGLRenderAction(SoGLRenderAction glAction) Defines the render action used for rendering.
void	setSceneGraph(SoNode newScene) Defines the scene graph which will be traversed for rendering.
void	setSize(SbVec2i32 size) Defines the image size to use for rendering.
void	setTile(SbVec2i32 size, int numEdgePixels) Defines the maximum sub-image (tile) size for rendering and the number of pixels on the border of each sub-image that are not written on the final image.
void	setTransparencyType(SoGLRenderAction.TransparencyTypes type) Defines the algorithm for rendering transparent objects.
void	setViewportRegion(SbViewportRegion newRegion) Defines viewport region (within the image) to use for rendering.

Methods inherited from class com.openinventor.inventor.Inventor

getNativeResourceHandle

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

onTileRendered

public final SbEventHandler<SoOffscreenRenderArea.EventArg> onTileRendered

Event raised when a tile has been rendered.

Constructor Detail

SoOffscreenRenderArea

public SoOffscreenRenderArea(SoGLContext glContex)

Builds a new offscreen render area by sharing the given SoGlContext.

SoOffscreenRenderArea

public SoOffscreenRenderArea()

Default constructor. NOTE: An internally created SoGLContext will be shared with the current context or an existing one if possible. In order to have control over the SoGLContext sharing, use the alternate constructor.

SoOffscreenRenderArea

public SoOffscreenRenderArea(SoRenderAreaCore renderAreaCore)

Builds a new offscreen render area by using the given renderAreaCore. Any following call to setSceneGraph will change the scene graph used by this instance.

Method Detail

onStartRender

public SbEventHandler<SiRenderArea.RenderEventArg> onStartRender()

Returns the event handler that raises when a new render starts.

Specified by:

onStartRender in interface SiRenderArea

isDisposable

public boolean isDisposable()

Description copied from interface: SafeDisposable

Returns a boolean flag which indicates if it is safe to call SafeDisposable.dispose() on the object.

Specified by:

isDisposable in interface SafeDisposable

Returns:

true if the object can be disposed in a safe manner

renderToBuffer

public boolean renderToBuffer(SoBufferObject buffer)

Calls renderToBuffer(buffer, SoOffscreenRenderArea.OutputFormats.valueOf( SoOffscreenRenderArea.OutputFormats.RGB.getValue() )).

renderToFile

public boolean renderToFile(java.lang.String filename)

Calls renderToFile(filename, SoOffscreenRenderArea.OutputFormats.valueOf( SoOffscreenRenderArea.OutputFormats.RGB.getValue() )).

dispose

public boolean dispose()

Description copied from class: Inventor

Explicitly call this method to force object to dispose its unmanaged resources. The object may not be reused in the application code after this call.

Specified by:

dispose in interface SafeDisposable

Overrides:

dispose in class Inventor

Returns:

true if this object native resources were successfully disposed; false if it was already disposed or no native resources has been registered for this object.

setTransparencyType

public void setTransparencyType(SoGLRenderAction.TransparencyTypes type)

Defines the algorithm for rendering transparent objects. Default is NO_SORT. See SoGLRenderAction for possible transparency types. See also SoGLRenderAction.TransparencyType.

Note: When using OPAQUE_FIRST, SORTED_OBJECT or SORTED_PIXEL transparency, the depth buffer is not updated (depth buffer writes are disabled) while rendering transparent objects. As a result complex 3D shapes may not be rendered correctly.

Specified by:

setTransparencyType in interface SiRenderAreaTransparency

getViewportRegion

public SbViewportRegion getViewportRegion()

See Also:

setViewportRegion()

render

public SiRenderArea.RenderStatus render()

Calling the render() method is useless and does nothing. This function returns always ABORTED.

Specified by:

render in interface SiRenderArea

getTransparencyType

public SoGLRenderAction.TransparencyTypes getTransparencyType()

Specified by:

getTransparencyType in interface SiRenderAreaTransparency

See Also:

setTransparencyType()

setAntialiasingQuality

public void setAntialiasingQuality(float quality)

Define the antialiasing quality value.

Specified by:

setAntialiasingQuality in interface SiRenderAreaAntialiasing

Parameters:

quality - The quality is a factor in the range [0.0,1.0].
Default is 0.0. The value 0.0 turns off antialiasing.

getSceneManager

public SoSceneManager getSceneManager()

Returns the encapsulated scene manager.

getAntialiasingQuality

public float getAntialiasingQuality()

Specified by:

getAntialiasingQuality in interface SiRenderAreaAntialiasing

See Also:

setAntialiasingQuality()

getMaxTileSize

public static SbVec2i32 getMaxTileSize()

Gets the maximum subimage (tile) size for rendering.

setClearPolicy

public void setClearPolicy(SiRenderArea.ClearPolicies policy)

Defines the color buffer and depth buffer clear policy. Default value is ClearPolicy.COLORBUFFER_AND_DEPTHBUFFER. Effects such as motion blur can be created by disabling clear color buffer or depth buffer. . See also setClearColor and setClearDepth.

Specified by:

setClearPolicy in interface SiRenderArea

Parameters:

policy - color buffer and depth buffer clear policy.

setViewportRegion

public void setViewportRegion(SbViewportRegion newRegion)

Defines viewport region (within the image) to use for rendering.

getSceneGraph

public SoNode getSceneGraph()

Specified by:

getSceneGraph in interface SiRenderArea

See Also:

setSceneGraph()

setSceneGraph

public void setSceneGraph(SoNode newScene)

Defines the scene graph which will be traversed for rendering.

Specified by:

setSceneGraph in interface SiRenderArea

Parameters:

newScene - scene graph.

getSize

public SbVec2i32 getSize()

Specified by:

getSize in interface SiRenderArea

See Also:

setSize()

setClearColor

public void setClearColor(SbColorRGBA color)

Defines the RGBA value used when the color buffer is cleared. Default is transparent black (0,0,0,0). This is the value used to clear the color buffer when renderToFile() or renderToBuffer() are called with setClearPolicy() method set to COLORBUFFER or COLORBUFFER_AND_DEPTHBUFFER . See also setClearPolicy.

Specified by:

setClearColor in interface SiRenderArea

Parameters:

color - RGBA value used to clear the color buffer.

getClearPolicy

public SiRenderArea.ClearPolicies getClearPolicy()

Specified by:

getClearPolicy in interface SiRenderArea

See Also:

setClearPolicy()

setGLRenderAction

public void setGLRenderAction(SoGLRenderAction glAction)

Defines the render action used for rendering.

getClearDepth

public float getClearDepth()

Specified by:

getClearDepth in interface SiRenderArea

See Also:

setClearDepth()

setClearDepth

public void setClearDepth(float depth)

Defines the depth value used when the depth buffer is cleared. The default value is 1. This is the value used to clear the depth buffer when renderToFile() or renderToBuffer() are called with setClearPolicy() method set to DEPTHBUFFER or COLORBUFFER_AND_DEPTHBUFFER . See also setClearPolicy.

Specified by:

setClearDepth in interface SiRenderArea

Parameters:

depth - value used to clear the depth buffer. Value is clamped to the range [0,1].

setSize

public void setSize(SbVec2i32 size)

Defines the image size to use for rendering.

Specified by:

setSize in interface SiRenderArea

getClearColor

public SbColorRGBA getClearColor()

Specified by:

getClearColor in interface SiRenderArea

See Also:

setClearColor()

setAntialiasingMode

public void setAntialiasingMode(SoSceneManager.AntialiasingModes mode)

Define the antialiasing mode.

Specified by:

setAntialiasingMode in interface SiRenderAreaAntialiasing

Parameters:

mode - The antialiasing algorithm. Default is NO_ANTIALIASING which turns off antialiasing.

renderToBuffer

public boolean renderToBuffer(SoBufferObject buffer,
                              SoOffscreenRenderArea.OutputFormats outputFormat)

Render the given scene graph and save the result in the given buffer. The buffer is resized if its current size is not equal to the the necessary size to store the rendering result.

If your application needs more control over creation of an output file, the SoBufferObject can be converted into an SbRasterImage using the appropriate constructor. Once instantiated, the SbRasterImage can be passed as a parameter to the write function of any class inheriting from SoRasterImageRW (SoJPEGImageRW for example to generate a JPEG file).

Parameters:

buffer - stores the result of the rendering.

outputFormat - defines which components to write to the output. If set to RGBA, the alpha component of the rendering is also written to the buffer.

getAntialiasingMode

public SoSceneManager.AntialiasingModes getAntialiasingMode()

Specified by:

getAntialiasingMode in interface SiRenderAreaAntialiasing

See Also:

setAntialiasingMode()

renderToFile

public boolean renderToFile(java.lang.String filename,
                            SoOffscreenRenderArea.OutputFormats outputFormat)

Render the given scene graph and save the result in the given file. The format of the generated image is chosen automatically according to the file extension. Returns true if successful.

If your application needs more control over creation of the file, please see the renderToBuffer() method.

Supported file types are:

extension file (case insensitive)	raster image type	Alpha Component Support
.bmp	Windows bitmap	YES
.dds	DirectDraw surface	YES
.gif	Graphics Interchange Format	YES
.hdr	hdr	NO
.jp2, .j2c, .j2k, .jpc, .jpx, .ecw, .ecwp	jpeg 2000	YES
.jpg, .jpeg, .jif, .jfif	Joint Photographic Experts Group	NO
.pgx	pgx	NO
.png	Portable Network Graphics	YES
.pnm .pgm .ppm	pnm	YES
.ps	PostScript	NO
.rgb .sgi	sgi	YES
.ras	sun	YES
.tif .tiff	Tagged Image File Format	YES

Parameters:

filename - path and name of the image file to be generated. If the file extension is not one of the above type, no file is generated.

outputFormat - defines which components to write to the output. If set to RGBA, the alpha component of the rendering is also written to the file. However if the targeted file type does not support alpha component, the file will be generated with RGB components only. See the 3rd column of the above table.

getNumEdgePixels

public int getNumEdgePixels()

See Also:

setTile()

getGLRenderAction

public SoGLRenderAction getGLRenderAction()

Returns the render action used for rendering.

setTile

public void setTile(SbVec2i32 size,
                    int numEdgePixels)

Defines the maximum sub-image (tile) size for rendering and the number of pixels on the border of each sub-image that are not written on the final image. The default tile size is set to the maximum viewport size supported by the hardware (GL_MAX_VIEWPORT_DIMS) and can be queried using the getMaxTileSize() method. The default value for the number of edge pixels is 2 pixels.

Edge pixels are usually required to avoid visual "artifacts" at the subimage boundaries. One source of artifacts is that when OpenGL clips lines, it draws a line between the points where the line exits and re-enters the visible region. This additional segment is not part of the actual geometry. A two pixel border will hide this undesired segment unless the line width is greater than two, in which case you may need to specify a larger number of edge pixels.

Parameters:

size - is dimension of the tile.

numEdgePixels - is the number of pixels on the edge of the tile which will not be included in the final image.

getTileSize

public SbVec2i32 getTileSize()

See Also:

setTile()