In 2016 I, the Emu, was seriously ill and spent some time in hospital
followed by three weeks recuperating in a German ReHa Klinik - a ReHa
being a cross between a hospital and a health spa. These scenes serve
as a reminder of my time there, which was remarkably enjoyable.

The scenes are all based on some photgraphs that I took with a mobile
phone, so the image quality is therefore somewhat poorer than I would
would prefer. I have modified some of the images to remove any names,
though anyone who knows the place will recognise it.  In  one  case I
have also made an edit to disguise someone appearing in the picture.

Most of these scenes are very basic with the only interrest being the
setting. However, those set in the ReHa's thermal baths are very much
more complex as they make the girls appear to be standing in water. A
number of technical difficulties had to be overcome before I was able
to produce a result that satisfied me.  These diffculties, with their
solutions, being:-

  1) Reducing the visibility of those parts of the girls that are
     below the surface of the water. This can be most easily done
     using partialy transparent strips showing the  pool  surface
     and slotting the clips of the girls between  them.  However,
     the result is not very satisfactory for two reasons. Firstly
     the surface of the water is static,  which  is  unrealistic,
     and secondly the step change in opacity at the water surface
     results in very distinct sharp horizontal line  across  each 
     of the clips which, again, is not realistic.

  2) Gentle movement of the water surface,  consistant  with  the
     distortions seen in the reflections present in the  original
     image of the pool, has been modelled using "wobble" shaders.
     Two alternatives have been used, one being a fragment shader
     and the other a vertex shader.  In each case the shader acts
     on an image of just the pool surface with the  output  being
     placed in a frame buffer.

  3) Once the water surface is animated the simple static  slices
     of the pool image had to be replaced with slices taken  from
     the framebuffer which recieved the animated water surface. A
     fragment shader that extracts a rectangular  section  of  an
     image is used for this. 
     
  4) Using simple rectangular regions extracted from the animated
     pool surface image still results in sharp  horizontal  lines
     marking the water level across each of the girls. The impact
     of these has een lessened by modifying the extraction shader
     so that it optionaly extends the rectangle that it  extracts
     by adding a border in which the opacity is  smoothly  varied
     from the value used inside the rectangle to that used on the
     outside,  i.e.  from the opacity used for water to that used
     for air. The borders of neighbouring strips are overlaped so
     that where there is nothing between them the combined effect
     of the two borders is the same as that of the  interiors  of
     the strips and is therefore invisible. Where, however, there
     is something between the strips only the front strip has any
     effect and the variation in opacity is seen, which makes the
     transition fuzzy thereby eliminating  the  sharp  horizontal
     lines marking where the girls emerge from the water.

  5) Iniialy the image used for the pool surface was just that of
     the pool in the original image with all areas outside of the
     pool being made transparent.  However,  there  were  several
     quite noticable features on the bottom of the pool and these
     were animated together with the features (reflections)  that
     were truely present of the pool surface. These unwanted pool
     bottom features, just like the wanted refections, would move
     to and fro across the images of the girls and  this  spoiled
     the effect of animating the pool surface. To reduce this the
     image used for the pool surface was edited to eliminate,  or
     at least reduce, the visibility of these features - this was
     mostly done using Gimp's smudge tool and its blur filter.

The final result of all this is quite satisfactory,  though there are
some minor failings.  The main failings that I can think of are

  1) The reflections are of things from the back of the pool,  as
     such they should be interrupted if a girl is standing in the
     middle of one, but they are not affected by the girls in any
     way. I can see no obvious way to fix this, but I also do not
     think it a problem as I hardly notice it.

  2) There are no refections of the girls.  These can probably be
     relatively easily be provided but as yet I have not  noticed
     their absence.

  3) The girls motions have no effect on the motion of the water.
     I doubt that it is possible to do anything about this.

  4) The parts of the girls that are underwater should appear  to 
     wobble and be somewhat foreshortened to model the effects of
     refraction. Also the transparency of the water really should
     decrease with depth.  These could be implemented in a shader
     acting on the clipSprites.

I have no current plans to do any of the above enhancements but it is
always possible that I will get round to  implementing  something  at
some time in the future.
