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 OIV.Inventor.SoOffscreenRenderArea.GetSceneGraph() method does not include the camera. It's always safer to get the OIV.Inventor.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.

Limitations:

• Can only generate an RGB image (not, for example, RGBA).

• Maximum output image size is 25000 x 25000 pixels.

  EXAMPLE

SoOffscreenRenderArea myOffscreen = new SoOffscreenRenderArea();
myOffscreen.setSize( new SbVec2i32( 15360, 8640 ) );
myOffscreen.SetSceneGraph(mySceneGraph);
if ( tileRendering )
 myOffscreen.SetTile(new SbVec2i32(3840, 2160), 2);

myOffscreen.SetClearColor( new SbColorRGBA(1.f, 1.f, 1.f, 1.f) );

myOffscreen.RenderToFile("result.png", 1.0f);

myOffscreen.RenderToBuffer(myBuffer);

Since Open Inventor 10.0

Reference