SoOffscreenRenderArea Class Reference
[General]
Render to an off-screen buffer for printing or generating textures. More...
#include <Inventor/SoOffscreenRenderArea.h>
Detailed Description
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
- See also:
- setAntialiasingMode().
- See also:
- setAntialiasingQuality().
- See also:
- setClearColor().
- See also:
- setClearDepth().
- See also:
- setClearPolicy().
- See also:
- setTile().
- See also:
- setSceneGraph().
- See also:
- setSize().
- See also:
- setTransparencyType().
- See also:
- setViewportRegion().
- 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. - 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. - Parameters:
-
mode The antialiasing algorithm. Default is NO_ANTIALIASING which turns off antialiasing. - 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. - Parameters:
-
color RGBA value used to clear the color buffer. - Parameters:
-
depth value used to clear the depth buffer. Value is clamped to the range [0,1]. - Parameters:
-
policy color buffer and depth buffer clear policy. - 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. - Inventor/SoOffscreenRenderArea.h
SoOffscreenRenderArea myOffscreen; // Set the size of the output myOffscreen.setSize( SbVec2i32( 15360, 8640 ) ); // Set the sceneGraph to render myOffscreen.setSceneGraph(mySceneGraph); // If you want to render by tile if ( tileRendering ) myOffscreen.setTile(SbVec2i32(3840, 2160), 2); // Specify the color of the clear performed before rendering, here clear with white color myOffscreen.setClearColor( 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::RGBA); // Or... Save the render in a buffer myOffscreen.renderToBuffer(myBuffer);
Member Enumeration Documentation
Constructor & Destructor Documentation
| SoOffscreenRenderArea::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::SoOffscreenRenderArea | ( | SoGLContext * | glContex | ) |
Builds a new offscreen render area by sharing the given SoGlContext.
| SoOffscreenRenderArea::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.
| SoOffscreenRenderArea::~SoOffscreenRenderArea | ( | ) |
Destructor.
Member Function Documentation
| virtual SoSceneManager::AntialiasingMode SoOffscreenRenderArea::getAntialiasingMode | ( | ) | const [virtual] |
Implements SiRenderAreaAntialiasing.
| virtual float SoOffscreenRenderArea::getAntialiasingQuality | ( | ) | const [virtual] |
Implements SiRenderAreaAntialiasing.
| virtual SbColorRGBA SoOffscreenRenderArea::getClearColor | ( | ) | const [virtual] |
Implements SiRenderArea.
| virtual float SoOffscreenRenderArea::getClearDepth | ( | ) | const [virtual] |
Implements SiRenderArea.
| virtual ClearPolicy SoOffscreenRenderArea::getClearPolicy | ( | ) | const [virtual] |
Implements SiRenderArea.
| virtual SoGLRenderAction* SoOffscreenRenderArea::getGLRenderAction | ( | ) | const [virtual] |
Returns the render action used for rendering.
| static SbVec2i32 SoOffscreenRenderArea::getMaxTileSize | ( | ) | [static] |
Gets the maximum subimage (tile) size for rendering.
| int SoOffscreenRenderArea::getNumEdgePixels | ( | ) | const |
| virtual SoNode* SoOffscreenRenderArea::getSceneGraph | ( | ) | const [virtual] |
Implements SiRenderArea.
| SoSceneManager* SoOffscreenRenderArea::getSceneManager | ( | ) | const |
Returns the encapsulated scene manager.
| virtual SbVec2i32 SoOffscreenRenderArea::getSize | ( | ) | const [virtual] |
Implements SiRenderArea.
| virtual SoGLRenderAction::TransparencyType SoOffscreenRenderArea::getTransparencyType | ( | ) | const [virtual] |
Implements SiRenderAreaTransparency.
| SbViewportRegion SoOffscreenRenderArea::getViewportRegion | ( | ) | const |
| virtual SbEventHandler<RenderEventArg&>& SoOffscreenRenderArea::onStartRender | ( | ) | [virtual] |
Returns the event handler that raises when a new render starts.
Implements SiRenderArea.
| virtual RenderStatus SoOffscreenRenderArea::render | ( | ) | [virtual] |
Calling the render() method is useless and does nothing.
This function returns always ABORTED.
Implements SiRenderArea.
| bool SoOffscreenRenderArea::renderToBuffer | ( | SoBufferObject * | buffer, | |
| OutputFormat | outputFormat = RGB | |||
| ) | const |
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).
| bool SoOffscreenRenderArea::renderToFile | ( | const SbString & | filename, | |
| OutputFormat | outputFormat = RGB | |||
| ) | const |
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 |
| virtual void SoOffscreenRenderArea::setAntialiasingMode | ( | SoSceneManager::AntialiasingMode | mode | ) | [virtual] |
Define the antialiasing mode.
Implements SiRenderAreaAntialiasing.
| virtual void SoOffscreenRenderArea::setAntialiasingQuality | ( | float | quality | ) | [virtual] |
Define the antialiasing quality value.
Implements SiRenderAreaAntialiasing.
| virtual void SoOffscreenRenderArea::setClearColor | ( | const SbColorRGBA & | color | ) | [virtual] |
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.
Implements SiRenderArea.
| virtual void SoOffscreenRenderArea::setClearDepth | ( | float | depth | ) | [virtual] |
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.
Implements SiRenderArea.
| virtual void SoOffscreenRenderArea::setClearPolicy | ( | ClearPolicy | policy | ) | [virtual] |
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. Use enum ClearPolicy. See also setClearColor and setClearDepth.
Implements SiRenderArea.
| virtual void SoOffscreenRenderArea::setGLRenderAction | ( | SoGLRenderAction * | glAction | ) | [virtual] |
Defines the render action used for rendering.
| virtual void SoOffscreenRenderArea::setSceneGraph | ( | SoNode * | newScene | ) | [virtual] |
Defines the scene graph which will be traversed for rendering.
Implements SiRenderArea.
| virtual void SoOffscreenRenderArea::setSize | ( | const SbVec2i32 & | size | ) | [virtual] |
Defines the image size to use for rendering.
Implements SiRenderArea.
| void SoOffscreenRenderArea::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.
| virtual void SoOffscreenRenderArea::setTransparencyType | ( | SoGLRenderAction::TransparencyType | type | ) | [virtual] |
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.
Implements SiRenderAreaTransparency.
| void SoOffscreenRenderArea::setViewportRegion | ( | const SbViewportRegion & | newRegion | ) |
Defines viewport region (within the image) to use for rendering.
Member Data Documentation
Event raised when a tile has been rendered.
The documentation for this class was generated from the following file: