The program tksipp is a Tk wish shell containing TSIPP and additional support for render to Tk photo images.
During the rendering of a scene, events will be handled via the Tk update mechanism. The update period may be specified as an option to any of the rendering commands. The unit of the update period is approximately the amount of time taken to render one pixel in an average scene. The updates themselves occur at points in the rendering other than the direct rendering of the picture, this time unit is just a guideline. Specifying a smaller period makes an application more responsive, specifying a larger period speeds the rendering.
SIPP commands may not be used by events that occur while rendering, they will return an error if this is attempted. The SippInfo command may be used to determine if rendering is in progress. An application should normally disable any widgets that might invoke a command that result in SIPP commands being executed while a during rendering. It is possible to abort a rendering in progress with the SippAbortRender command.
See the Tk photo image manual page for details in how to create and manage Tk photo images. Photo images may have images displayed on it with the SippRender or the SippCopy commands. The images is initialized to the background color at the start of the output. Photo images have no internal background color, by default, they are transparent. I maybe desirable to set the background color of the widget that the image is to be displayed on to be background color that will be used during rendering. The SippColor command can be useful for this.