What a scanner sees with and without indentations

What a scanner sees with and without cavities.  The red line is a verticle beam of light that when shone on a sphere from about 30 degres - it forms a curved line.  If that sphere has an indentaion - a normal sillohette profile will not show the indentation as anything deeper than a flat spot.  But because this line is shone from an oblique angle it will curve inwards whenever an indentaion is illuminated by the line.  The software is then able to calculate the depth of the indentation (within some limits).  This idea has been used in many industries - but Sergey and the Octonus team were first to use it from 2 sides at once there-by capturing more depth from certain types of cavities and avoiding the polishing of stones with unacceptable yucky cavities.