public void setAlphaBits(int value) {
        putInteger("AlphaBits", value);
    }
Android Only
Sets the number of alpha bits to use.
<p>
The number of alpha bits specifies the precision of the surface view
background alpha value.  To set the surface view to opaque (fastest setting),
leave the number of alpha bits = 0.  This will cause faster rendering,
but android views located behind the surface view will not be viewable.
To set the surface view to translucent, set the number of alphaBits to 8
or higher.  Values less than 8 (except 0) will set the surface view pixel
format to transparent. <p>
(Default: 0)

@param value The alpha bits
jme3-core/src/main/java/com/jme3/system/AppSettings.java