Fall and Bounce
Realistic non-linear movements with useful basic functions.

//---------------------------------
#macro  Fall_10( X )
  (  sin(pi*(1/2*X + 1/2)) )
#end
//---------------------------------
#macro  Bounce_101( X )
 #if(X0<1/2) (sin(pi*( X + 1/2)))
 #else       (sin(pi*(1-X + 1/2)))
 #end
#end //----------------------------

//---------------------------------
#macro  Bounce_101( X )
 #if(X<1/2) (sin(pi*( X + 1/2)))
 #else      (sin(pi*(1-X + 1/2)))
 #end
#end //----------------------------
#declare Time = clock +0.00  ;
//---------------------------------
sphere{ <0,0,0>,0.15
  texture{
    pigment{ color rgb<0.3,0.7,0>}
    finish{ phong 1 }
    }
  translate
  <0.25, Bounce_101(Time)*(1-0.15)+0.15,0>
} // end sphere

//---------------------------------
#declare Time = clock +0.00  ;
//---------------------------------
sphere{ <0,0,0>,0.15
  texture{
    pigment{ color rgb<0.3,0.7,0>}
    finish{ phong 1 }
    }
#if(Time<0.5)
 translate<0.25,(1-Time*2)  *(1-0.15)+0.15,0>
#else
 translate<0.25,(Time-0.5)*2*(1-0.15)+0.15,0>
#end
} // end sphere