Show legend on cesium slope, aspect and elevation

CesiumJS
9

First of all, I’m very thankful to you to help me out and for explaining very well it is useful but still, I’ve few queries which I need to explain to my client like:-

  1. Can u pls send me the origin of given formula if it is available - 0.1*[8777-(-414)] + (-414) = 505.1
    // elevationRamp * [maxHeight-(minHeight)]+(minHeight)
  2. In the same manner how I’ll get slope in degree and aspect sides(like north, south, east, west, north-south, etc.) as given in images I sent you, is there any formula for the slope and aspect.
    Aspect-Map-Legend SlopeMap

Thanks in Advance
Shashi