The Geometrical Shapes subdirectory contains sets of images of  various
basic geometrical shapes.

Each set should include one with hard edges, some with softer edges and
optionaly a few with fuzzy edges. With large fuzz factors many of these
shapes become indistinguishabale from a fuzzy disc, but I have included
them anyway in order that there is complete series of versions for each
shape.

The shapes are all coloured white on a transparent background, a normal
color: clause in the scene node can then be used to recolour them. They
all should have the same basic size, 1000 x 1000,  before any softening
is applied.  The softening operation will increase the overall size but
preserves the base size.

The normal size, scale and rot clauses in the scene file can be used to
change their sizes, aspect ratios or orientations and the Shear, Taper,
TaShe and other shaders from the library, or eleswhere,  can be used to
modify their shapes.

Currently the following shapes are provided

   Disc (circle)
   Quad (square)
   Triangle 1 (equlateral)
   Triangle 2 (right angled)
   Star (5, 6 and 8 pointed stard)
   Ring (with variously sized holes)

Elipses, rectangles, parallelograms, trapezia,  other triangles etc. can
be obtained by distorting these basic shapes. Two types of triangle have
provided for convenience even though only one was strictly necessary.

For many of the shapes a second set of shapes corresponding to a half of
the of the main shape is included. For these the cutting of the shape in
half has been done after blurring so the cut side is not blurred.  These
half shapes are primarily intended to be used in pairs that fit together
to reconstruct the full 2D shape with some other object being sandwiched
between the two halves. These half shapes are indicated suffixing (half)
to the file name. 

Subdirectories are used to group related sets of shapes.

Notes:

Each image is sized such that either one side of a shape or its diagonal
is 1000 pixels.

Each file name ends with number that the degree of blurring that has been
applied to the original hard edged image which has a blur factor of 0.

The blurring was done using GIMP by

   Increasing the images canvas size to 2000 or 4000 pixels.
   Applying Gaussian blur with a radius equal to the wanted blur factor.
   Autocropping the image to reduce its size.
   Exporting it as a png without saving the colour of transparent areas.

The same procedure should be used for all shapes.


