The following methods provide access to the values in the Viewport Background dialog.

getBkgFrameNum <time>      

Returns the viewport background image frame displayed at the specified time. Returns a value of -1 if no frame is to be used for specified time.

getBkgImageAnimate()      
setBkgImageAnimate <boolean>   

Get and set whether Animate Background is on ( true ), or off ( false) .

getBkgImageAspect()   
setBkgImageAspect <name> 

Get and set the background image Aspect Ratio option. Valid <name> values are:

#view -- Match Viewport 
#bitmap -- Match Bitmap 
#output -- Match Rendering Output 

getBkgORType <start_end_integer> 
setBkgORType <start_end_integer> <name> 

Get and set the background image Start Processing and End Procession options.

<start_end_integer> = 0 - Start Processing; 1 - End Processing

Valid <name> values are:

#blank -- Blank Before Start/After End 
#hold -- Hold Before Start/After End #loop -- Loop After End 

getBkgRangeVal() 

Get the background image Use Frame range as a Point2 value. The first component of the Point2 value is the Start Frame, the second component is the End Frame.

setBkgFrameRange <point3> 

Set the background image Use Frame range and step value. First component of <point3> is Start Frame, second component is End Frame, and third component is Step Frame.

getBkgStartTime() 
setBkgStartTime <time> 

Get and set the background image Start At frame.

getBkgSyncFrame() 
setBkgSyncFrame <integer> 

Get and set the background image Synch Start To Frame frame.

The following 3ds Max system global variable is associated with the Viewport Background dialog:

backgroundImageFileName 

Lets you get and set a String value that defines the viewport background image bitmap file name. It contains the corresponding bitmap file name set in the Viewport Background dialog.

setAsBackground <bitmap> 

Sets the specified bitmap as the viewport background image. The <bitmap> must be associated with a bitmap file, which is true if:

1 - the bitmap is read from a file via openBitmap() or selectBitMap();

2 - the bitmap was saved via save <bitmap>;

3 - the MAXBitMap constructor is passed a BitmapInfo whose Name length isn't 0 (for example if you retrieve a bitmap from a BitmapTexture); or

4 - the bitmap is saved in the render() command.

The following method affects Viewport Background redraws:

InvalidateAllBackgrounds() 

Invalidates the viewport background image for all viewports, causing then to be redrawn