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Hi,
for an animation I'm currently working on I wanted complicated rounded
pieces of wood, so I wrote macros to create these shapes. To get a first
impression what these macros can do, just open the attached file Brett.in
c
in POV, and
in POV-Ray 3.5:
replace the '233' in the following options line (sorry for eventual
wrap around) by the clock frequency (in megahertz) of your computer,
// +SP8 +EP8 +W512 +H384 -A -FN +D Declare=BrettDebug=0 Declare=
Typ=0 +KFF13 Declare=Show=233
then render Brett.inc (as if it were a .pov-file) with these command
line options.
in POV-Ray 3.1:
uncomment the line 60 '// #declare Show = 233;' in Brett.inc,
replace the '233' by the clock frequency (in megahertz) of your Compu
ter,
then render Brett.inc (as if it were a .pov-file) with the following
command line options:
+SP8 +EP8 +W512 +H384 -A -FN +D +KFF13
A sequence of demo pictures will be displayed (and when the end is there,
you will know it ...) with a short pause between them (timed by the
megahertz-number). Look and enjoy!
== Do you want to use this stuff? ==
Here is a more detailed explanation:
=== Using Brett.inc in a scene: ===
Just include it, then use the macros (explained below).
No variables named 'Show', 'BrettDebug', 'Nr' may exist at the moment of
the #include.
'BrettSegmente', 'Eps' will be used when defined, else they are declared
with their default values 50, 0.0001.
=== Parameters for Brett.inc when used to create demo scenes: ==
=
Show: MHz of the computer: automatic 'slide show'
<=0 or undefined : no show
Nr: 1 ... 13 : Number of demo scene (ignored by 'slide show')
other value or
undefined : no scene (for usage as include file)
Typ: 0: rounded
1: beveled
BrettDebug: 0: normal
1: marker arrows and debug info to #debug-stream
2: arrows, #debug and 'explosion' (to see how it's done)
=== Demo scenes with POV-Ray version 3.5 ===
Use one of the option-lines below with appropriate values for the
'Declare='-variables as command line options and render like a
.pov scene file
Slide show: see above
Small picture:
+SP8 +EP8 +W320 +H240 -A -F +D Declare=BrettDebug=0 Declare=Typ=0
Declare=Nr=1
Larger and nicer picture:
+SP8 +EP8 +W1024 +H768 +A0.1 -F +D Declare=BrettDebug=0 Declare=Typ
=0 Declare=Nr=1
=== Demo scenes with POV-Ray-Version 3.1 ===
Un-comment the lines 75-77 in Brett.inc ('#declare ...'), set the variabl
es
to appropriate values, use one of the option-lines below and render like
a
.pov scene file
Show: see above
Small picture:
+SP8 +EP8 +W320 +H240 -A -F +D
Larger and nicer picture:
+SP8 +EP8 +W1024 +H768 +A0.1 -F +D
=== Dictionary ===
All names of macros, variables etc. are in german,
so here is a small dictionary:
abgerundet rounded
Anfang beginning
Bogen (part of a) circular line
Brett (wooden) board
Dicke thickness
Ende end
erzeugen to create
Fass barrel
Fehler error
Gerade straight line
Holz wood
Kante edge
Letzter (here:) most recent
Punkt point
Richtung direction
Schluss-... end-..., closing-...
Schnitt (here:) intersection
Senkrechte perpendicular
Typ type (here: rounded/beveled)
Winkel angle
Schickard is the name of the inventor of the first satisfactorily working
mechanical calculating machine, built in 1623. I'm working on an animatio
n
showing the operation and inner workings of this device. The demo-scene 6
will create the left and right side parts of this machine.
=== The macros etc. of Brett.inc ===
Purpose: to create an object from a 'sheet' (the volume between the XZ-pl
ane
and the plane parallel to it at y=thickness) by straight and circular c
uts.
Its edges are rounded/beveled by attaching a strip around its circumferen
ce.
The shape is described by giving a starting point and direction (in the
XZ-plane), then 'driving' clockwise around, giving a radius (zero is lega
l)
and an angle by which the direction is to change (in degrees, +:turn righ
t,
-: turn left) for a circular segment, or a length and an angle of 0 degre
es
for a straight segment. Optionally this path may be automatically closed
by
a straight--circular--straight path with given radius for the circular
segment. The rounding/beveling is created by ATTACHING material to the ou
ter
contour of this figure, so the shape will EXPAND by the radius of roundin
g /
amount of beveling. The code of the demo scene 4 (following a #case (4)
directive) and macros E1, D1 and D2 of scene 13 should make quite clear h
ow
the Brett-macros are used.
Macros:
BrettAnfang ( thickness, type, rounding_radius, start, direction )
starts a new object
BrettKante ( radius_or_length, turn_degrees_or_zero )
defines a segment of the contour
BrettMulti ( radius, turn_degrees, number_of_segments )
defines a sub-divided segment (compare scenes 5 and 6)
BrettEnde ( radius_for_closure )
closes the contour (use BrettEnde(-1) if already closed)
Brett ()
creates the object as a union { ... }
Segment ( major_radius, minor_radius, angle )
(internal usage:) creates a segment of a torus/cone-ring
XZ_Senkrechte ( vektor )
(internal usage)
gives a normalized vector in the XZ-plane perpendicular
to the projection of the given vector onto the XZ-plane
XZ_Winkel ( Vektor1, Vektor2 )
(internal usage)
calculates the angle between the projections of the given vectors
onto the XZ-plane
XZ_Schnitt ( position_1, direction_1, position_2, direction_2 )
(internal usage)
let line_N be the line through position_N in direction_N,
projected onto the XZ-plane. This macro finds the intersection
point of line_1 and line_2 and declares 3 variables:
L1: distance from (position_1 projected onto XZ-plane) to this
intersection point
L2: same with position_2
W : angle between L1 and L2
(for an application see macro N1 in scene 13)
BrettkanteErzeugen ( Index )
(internal usage)
Saeule ( ... )
please look at the code and scenes 8 and 9; it's simple
demo scenes
selected with a #select directive; see the #case(...) directives
Nr=1 ... 13: scene 1 ... 13
0 : no scene (for usage as include file)
Variables:
Show, Typ, Nr, BrettDebug: see beginning of this text
Eps : a small number to avoid coincident surfaces
BrettSegmente : max. number of segments
BrettR : (internal usage) radius for rounding/amount of beve
l
BrettT : (internal usage) type
BrettD : (internal usage) thickness
BrettI : index of the most recent segment's endpoint
BrettS : (internal usage) radius for closure
BrettK[] : (internal usage) radii / lengths
BrettP[] : (internal usage) points
BrettV[] : (internal usage) directions
BrettW[] : (internal usage) angle between x and BrettV[...]
For further information look at the scenes or ask me ( but allow for a
couple of days for me to react :) ). If you want to look at the inner
workings, try BrettDebug=1 or =2.
Some scenes have parameters at their beginning (after the #case (...));
play with them and have fun!
ATTENTION!
I intend to develop greatly improved macros, but this will take some time
and they will definitely be INCOMPATIBLE with Brett.inc, because the new
macros will allow to specify the OUTER contour (i.e. no expansion due to
padding) and will have many more features, for example other types of
rounding; see the long list of planned features in Brett.inc (in german .
..).
Sputnik
P.S. If you don't like my indentation, replace all occurrences of
'<space><space>#end' by '#end', and of
'<space><space>}' by '}'. :)
--
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e-mail: fr### [at] computermuseum fh-kielde
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