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polydraw_1
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!PolyDraw
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!Help
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1997-08-29
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!PolyDraw
The PolyDraw application can draw two kinds of plot for
one of a set of stored polyhedra.
Starting the application:
Click on !PolyDraw to load it on to the icon bar.
Stopping the application:
Click MENU over the icon on the iconbar and choose the
last option, 'quit'. If windows are hiding the icon bar,
press key F12 while holding down the SHIFT key, to bring
the iconbar to the front of the windows.
Turn on !Help (in Apps) for continuous help over windows
Click SELECT over the !PolyDraw icon on the icon bar to
see the 'Selected Polyhedra' window, which shows blue
polyhedron names in white boxes.
Red titles separate the types of polyhedra.
Some polyhedra have alternate names listed below them in
green. Use the scroll bar to see more polyhedra names.
Plot a polyhedron either by clicking SELECT on a blue
name, by dropping a data file on to the icon on the
iconbar, or by double clicking on a data file with
filetype 'PolyData' 152. (Click ADJUST over a
highlighted blue icon to display the data in an editor.)
You should see more windows, there are three by default,
showing different forms of plot, with a planar net on the
left, a wire 3D solid view on the right, and text
describing the solid in a small window on the left below.
Rotating the solid:
The arrowed Cursor keys, and the 'Page up' and 'Page down'
keys rotate the solid; < and > change its size, when the
top bar of the 3D window is coloured yellow.
Click SELECT anywhere inside the window to turn the top
bar yellow when it is grey.
Hold down the 'CTRL' key at the same time as you press
a cursor key for continuous rotation at timed intervals.
Stop this by pressing any key or clicking the mouse.
If your computer is very fast you can get faster rotation
by holding down a cursor key.
The default angle through which the solid rotates is 10°.
To change this click MENU over the 3D window as described
below.
Click over the direction 'rotation' icons of the 'tools'
pane to rotate the solid, or hold down a mouse key for
continuous rotations. The SELECT button gives rotation
one way, ADJUST the opposite way.
3D MENU and plotting options
The 3D window has the name of the polyhedron as the title
of the window. Click MENU over the 3D window to:
• change the form of the display.
Forms are:
- a 'wire' frame view, front edges black,
back ones green
- red/green stereo 2 'wire' plots to see as 3D
- onecolour - all faces are the same colour, white by
default for grey scale shading
- datacolour - face colours are set by the colour
index read from the data file. These can be changed
on the screen; all faces with that colour index
will change.
- sidecolour - face colours depend on the number of
sides of the polygon making the face.
- localcolour - initially the same as datacolour, but
now if the colour is changed, only the one face
changes. Try colour 'None' on a face to see inside.
All coloured forms can be shaded using the sub-menu.
To see them correctly shaded the mode of your Desktop
should use at least 256 colours.
• alter the angle by which the 3D solid is rotated for
one key press, or mouse button click.
• add perspective to the plot (useful for stereo pairs)
• change the light direction
(only affects the shaded types)
• see the 'tools' pane
• ask to see the dual of this polyhedron, provided it is
named in the data file.
• save the plot as a Draw file in the usual way by
dragging icon to a filer window.
Click SELECT over a face or vertex to list its number,
colour number, and number of vertices in the face in a
small 'Face Data' window at lower right.
Click ADJUST over a face to change its colour using the
Acorn 'Colour Picker' window, the results depend on which
display form you have selected. Colour 'None' allows you
to see though the face to the inside of the polyhedron,
where all faces are drawn black with white lines round them.
If you make enough faces colour 'None' you can see through
the polyhedron to the other side.
Measuring distances and angles on the 3D solid
You can measure:
• a distance (D) between 2 points (must be different)
• the angle between 2 lines (A) defined by 3 points
• the angle between 2 planes, the inter-planar angle (I)
defined by 2 faces
First tell the program which measurement to do by:
either clicking SELECT over the icon in the tools pane
or by pressing one of the 'short cut' keys, D, A, I
(the letters in the ( ) above)
The text in the small 'face data' window changes to tell
you what to do next. Define a face by clicking SELECT
over it; define a vertex by clicking SELECT over it.
Click ADJUST anywhere in the 3D solid window to abandon
any measurement.
A 'bell' sound while measuring means the program does not
understand what you want; make sure the pointer is over a
face, or near to a vertex before clicking again.
A successful click gives a line in the 'face data' window
telling you the point or face you clicked over. The last
line gives the result of the measurement.
Notes:
1. The distance is scaled to the original size as in the
data file before printing, it does not depend on the
size seen on the screen.
2. An interplanar angle of
• 0° means the faces are in the same plane
• 180° means the faces are parallel to one another,
but are pointing in opposite directions.
Net plotting options
The net window also has the name of the polyhedron
as the window title. Click MENU over the net window to:
• change the form of the display, the colours are the
same as those for the 3D solid.
• save the plot as a Draw file.
Click SELECT over a face or vertex to list its number,
colour number, and number of vertices in the face in a
small 'Face Data' window at lower right.
Click MENU over the icon on the icon bar for a menu
where you can turn off any of the display windows,
save the choices, display this help,
show the 'selections' window or quit.
Making Selections
You can change the list of polyhedra either by dropping
a file from the 'PolyLists' directory on to the icon on
the icon bar, or by using the 'Selections' window.
You can get this either by choosing 'Select' from the
menu over the iconbar icon or by clicking with MENU
over the polyhedron list window.
This window is divided into three parts.
1) Down the left side you can select the type of
polyhedra to display. At least one of the boxes will
always be selected. Either use 'All' or any number of
the types below. Click SELECT or ADJUST over box or name
to change its state. A 'tick' or other symbol in the box
means this type of polyhedron will be selected.
2) The top part of the right hand side then lets you
restrict the selection to polyhedra having:
• a text string as part of its name,
• faces with a range of numbers of sides,
• a range of numbers of faces
The default values for these ranges are the minimum and
maximum found in the types in the PolyList file. The
selection is active only if it is ticked.
Click with SELECT over the white indented boxes to see
the caret, then type into them, pressing the RETURN key
at the end, which will store the data and tick the box
above to show that the selection is active.
Alternatively use the up/down arrow icons to the right of
the numeric selections.
For example, to select only solids made of triangles and
squares, with less than 20 faces, type 4 into the
'polygon sides' max box, and 20 into the 'polyhedron
faces' max box.
3) the action icons at the bottom right:
• Save the selections to the Choices file for use next
time you use the program,
• Cancel the changes you have just made to the
selections,
• Reset the selections from the Choices file
• OK to apply the choices
In fact all these actions apply the selections and open
the Polyhedron list window. Clicking with ADJUST over the
actions leaves the Selection Window open so you can
compare the selections with the resulting list of
polyhedra while clicking SELECT closes the window.
Key shortcuts
You may prefer to use the keyboard instead of the mouse.
The following keys are used in !PolyDraw:
• F1 displays this on-line help
• F12 with SHIFT brings the iconbar to the front
• <> make the 3D solid view bigger and smaller within limits
• arrow keys and 'Page Up', 'Page Down' rotate the solid
CTRL with any rotate key gives continuous timed rotations
• D (or d ) measure a distance between 2 vertices
• A (or a ) measure an angle between 3 vertices
• I (or i ) measure an inter-planar angle
Making a stereo pair Draw file
You can see a red/green stereo view on the screen, to see
it in 3D use the red/green cardboard viewing glasses
provided. It is often easier to see the effect if the
solid is rotating. Red/Green stereo cannot be easily seen
in a Draw file because these do not have a black
background.
You can see stereo in a Draw file using two
'side-by-side' stereo images. Some people can defocus
their eyes slightly, to see the polyhedron in 3D. ( I
can't do this myself, I need to have a small cardboard
viewer with clear plastic lenses. We are trying to find
a cheap source of these; if you know of one please let us
know the address.
The file 'Docs.Stereo' is an example of a 3D plot. You
make it by saving one plot to a Draw file; use !Draw to
reduce the size to fit in a square of about 6.5cm on a
side. Then rotate the plot in !PolyDraw by 5 degrees to
the left in the X direction, save the plot to the same
Draw file, use !Draw to fit the plot into a 6.5cm square,
and place it just to the right of the 1st one. The 6.5cm
is the distance between your eyes, if yours are a
different distance, use that instead.
Further information:
This is stored in the directory '!PolyDraw.Docs'
including an explanation of all files needed,
definitions of file formats and instructions on
how to add your own new polyhedra.
Look at the Draw file 'Docs.DrawEx1',
to see how the appearance changes with the
different forms of display.
Fault Reports:
If you find an error, please copy the file
'Docs.FaultRep' to another one, named for example
'EReport', and use an editor to complete the form to
tell us what you were doing when the error happened.
Send the report to us at the address below, preferably
with an example data file. The more details you can give
us the more likely it is that we shall be able to
reproduce your problem and correct the fault.
'Fortran Friends', P.O.Box 64, Didcot, Oxon, OX11 0TH