My new 17-value airbrush characters seem to be working – now if I can only get my airbrush to not clog up after an hour or 30 minutes or 90 minutes – otherwise it’s gonna require constant supervision which ain’t worth it (and BORING)!
Apple QuickTime movie of painting underway
Here’s an image of my spreadsheet calculations of area – I’ve made a set of ‘gestures’ – diamonds, and squares in various sizes and an ‘X’ and a ‘+’:
The ‘X-area’ column is the list of gestures D for Diamond, S for Square, X for diagonals, and P for Plus and the 3-digit number is the area in thousandths that an eighth inch line produces in a 1 inch box.
These are designed to be overpainted in each of red, yellow, blue, and black according to the color and value content of the corresponding area of an image. I’ve got a sample image partially painted in yellow, blue, and red now and it’s pretty much electrically brilliant! There are 17 to the 4th theoretical color possibilities (83,000 plus variations), so PLENTY of variation!
THEN I had to write the program to analyze the image and write the ShopBot code – my code reads an initialization file I wrote in ShopBot code which defines the characters and the subroutines to call them, then the program goes on to analyze each pixel in the image and generate the ShopBot code to position the machine to the pixel and do the painting. The SO,3,1 turns on the airbrush and SO,3,0 turns it off. M2 means Move in 2 dimensions (x,y) – J2 means FAST Jog in 2 dimensions (x,y)
Sub output_sbpcode_for_cmyk() ' 1/26/2007 gesture generator... Mike Lyon
' THE NEXT TWO LINES ARE FOR CONVENIENCE IN INITIALIZING CURRENT DRAWING LOCATION
' IT'D BE A GOOD IDEA TO ENTER THIS LOCATION IN THE FORM ALONG WITH &scale
PrintLine(3, "SO,3,0")
PrintLine(3, "J2,8,45")
PrintLine(3, "' MRL-generated GESTURE CODE from image")
PrintLine(3, "' position bot at top left of drawing first!")
PrintLine(3, "&xstart = %(1) ' remember beginning x value")
PrintLine(3, "&ystart = %(2) ' remember beginning y value")
PrintLine(3, "&scale = .4 ' this is 1=100% of 1 inch, .4 = .4")
PrintLine(3, "&rrr = 0 ' initialize rows (Y) variable")
PrintLine(3, "&ccc = 0 ' initialize X variable")
skipit = 0
lines_written = 10 ' TO ACCOMODATE TWO LINES ABOVE -- NORMALLY SET TO 0
PrintLine(3, "GOTO ROW_1")
While Not EOF(1) ' include the gesture subroutines file
sbp = LineInput(1)
PrintLine(3, sbp
lines_written += 1
End While
For rrr = 0 To rawimage.Height - 1
PrintLine(3, "ROW_" & rrr + 1 & ":")
PrintLine(3, "&rrr = " & rrr)
lines_written += 2
For ccc = 0 To rawimage.Width - 1
' getbrightness returns value from 0 to 1 where 0 is black and 1 is white
zz = Math.Round((1 - rawimage.GetPixel(ccc, rrr).GetBrightness) * 16, 0)
' 0 is digits to rt of decimal
If zz > 0 Then
If skipit > 0 Then
skipit = 0
End If
PrintLine(3, "&ccc = " & ccc)
PrintLine(3, "GOSUB " & zz.ToString("00"))
lines_written += 2
Else ' zz = 0
skipit += 1
End If
If Button5.Text = "END" Then Exit Sub
Next ccc
Label20.Text = "Writing " & rrr & " --- " & lines_written
ProgressBar1.Value = 100 * rrr / rawimage.Height
Call updateform()
If Button5.Text = "END" Then Exit Sub
Next rrr
PrintLine(3, "J2,&xstart,&ystart ' back to initial location and ready for next color")
PrintLine(3, "END")
lines_written += 2
End Sub
lines_written += 2
End Sub
This is actually only the working part of a MUCH longer program – the long program gets input from a screen, checks to make sure it all makes sense, and then calls the appropriate operation, in this case the subroutine above… Here’s what the screen looks like when the program is running (just finished generating the ShopBot code for the color ‘cyan’ for a Jim Winter drawing:
COOL, eh? I added the new code onto my existing program so I wouldn’t have to rewrite all the file and form handling – can’t believe it actually works!!!
I’ve defined some subroutines named after each of the 17 possible values (00 through 16 is white through black) which call the gestures I’ve designed to produce the values -- – the first routine listed below is for ‘black’ or value 16 – it calls .313” square, .438 square, .234” plus, and .338” diagonals in turn to produce the ‘shading’ in that area.:
Then I defined the movement for each ‘gesture’ – these are shown below as ShopBot subroutines – you can ‘call’ the subroutine (GOSUB D375 calls the .375 square inch diamond, for example) – the starting corner position is assumed to be in the variable “&xstart” and “&ystart” and the scale factor in &scale. Then the row and column indexes are in &rrr and &ccc variables – in a 100 row x 50 column image, for each rrr (1 through 100) I position to each column ccc (1 through 50) and draw the gestures for that position.
Finally, here’s just the very beginning of the completed code to produce 0.4” squares (&scale = .4) for a very STUPIDLY large drawing 200 squares high by 110 squares wide… Next time I’ll start a bit smaller :-)
SO,3,0 ‘ turn off the airbrush
J2,8,45 ‘ jump to the beginning of the drawing – remove this for normal operation – this is for debugging only
' position bot at top left of drawing first!
&xstart = %(1) ' remember beginning x value
&ystart = %(2) ' remember beginning y value
&scale = .4 ' this is 1=100% of 1 inch, .4 = .4
&rrr = 0 ' initialize rows (Y) variable
&ccc = 0 ' initialize X variable
GOTO ROW_1 ‘ jumps around the gesture subroutines which follow below and get right to the painting!
' this is the start of a gesture subroutines file
' scaling of &scale = 1 (100%) makes marks in a 1" square
' at &scale = 1 (100%) marks are to be 1/8" wide
' gesture call names are LETTER followed by number nnn
' D = diamond shape of .nnn area
' S = square shape of .nnn area
' X = crossed diagonals of .nnn area
' P = 'plus' (vertical & horizontal) of .nnn area
' main calls are 00 through 16 and represent values (tone or shade) from white to black
16:
' this is entry point to produce darkest gesture (value 16)
GOSUB S313
GOSUB S438
GOSUB P234
GOSUB X338
RETURN
15:
' entry point to produce next to darkest gesture (15)
GOSUB S188
GOSUB S438
GOSUB P234
GOSUB X338
RETURN
14:
GOSUB S438
GOSUB P234
GOSUB X338
RETURN
13:
GOSUB D375
GOSUB S063
GOSUB S438
RETURN
12:
GOSUB D375
GOSUB S438
RETURN
11:
GOSUB D250
GOSUB S438
RETURN
10:
GOSUB D375
GOSUB X338
RETURN
09:
GOSUB D250
GOSUB S063
GOSUB X338
RETURN
08:
GOSUB D250
GOSUB X338
RETURN
07:
GOSUB S188
GOSUB X338
RETURN
06:
GOSUB D375
RETURN
05:
GOSUB S313
RETURN
04:
GOSUB D250
RETURN
03:
GOSUB S188
RETURN
02:
GOSUB D125
RETURN
01: ' entry point to produce next to lightest gesture
GOSUB S063
RETURN
00: ' entry point to produce blank (do nothing)
RETURN
D375: ' entry point for 37.5% diamond
J2, &xstart + &scale * ( &ccc + 0 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.5 ), &ystart - &scale * ( &rrr + 1 )
M2, &xstart + &scale * ( &ccc + 1 ), &ystart - &scale * ( &rrr + 0.5 )
M2, &xstart + &scale * ( &ccc + 0.5 ), &ystart - &scale * ( &rrr + 0 )
M2, &xstart + &scale * ( &ccc + 0 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,0
RETURN
D250: ' entry point for 25% diamond
J2, &xstart + &scale * ( &ccc + 0.125 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.5 ), &ystart - &scale * ( &rrr + 0.875 )
M2, &xstart + &scale * ( &ccc + 0.875 ), &ystart - &scale * ( &rrr + 0.5 )
M2, &xstart + &scale * ( &ccc + 0.5 ), &ystart - &scale * ( &rrr + 0.125 )
M2, &xstart + &scale * ( &ccc + 0.125 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,0
RETURN
D125: ' entry point for 12.5% diamond
J2, &xstart + &scale * ( &ccc + 0.375 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.5 ), &ystart - &scale * ( &rrr + 0.625 )
M2, &xstart + &scale * ( &ccc + 0.625 ), &ystart - &scale * ( &rrr + 0.5 )
M2, &xstart + &scale * ( &ccc + 0.5 ), &ystart - &scale * ( &rrr + 0.375 )
M2, &xstart + &scale * ( &ccc + 0.375 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,0
RETURN
S438: ' entry point for 43.8% square
J2, &xstart + &scale * ( &ccc + 0.0625 ), &ystart - &scale * ( &rrr + 0.0625 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.0625 ), &ystart - &scale * ( &rrr + 0.9375 )
M2, &xstart + &scale * ( &ccc + 0.9375 ), &ystart - &scale * ( &rrr + 0.9375 )
M2, &xstart + &scale * ( &ccc + 0.9375 ), &ystart - &scale * ( &rrr + 0.0625 )
M2, &xstart + &scale * ( &ccc + 0.0625 ), &ystart - &scale * ( &rrr + 0.0625 )
SO,3,0
RETURN
S313: 'entry point for 31.3% square
J2, &xstart + &scale * ( &ccc + 0.1875 ), &ystart - &scale * ( &rrr + 0.1875 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.1875 ), &ystart - &scale * ( &rrr + 0.8125 )
M2, &xstart + &scale * ( &ccc + 0.8125 ), &ystart - &scale * ( &rrr + 0.8125 )
M2, &xstart + &scale * ( &ccc + 0.8125 ), &ystart - &scale * ( &rrr + 0.1875 )
M2, &xstart + &scale * ( &ccc + 0.1875 ), &ystart - &scale * ( &rrr + 0.1875 )
SO,3,0
RETURN
S188: ' entry point for 18.8% square
J2, &xstart + &scale * ( &ccc + 0.3125 ), &ystart - &scale * ( &rrr + 0.3125 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.3125 ), &ystart - &scale * ( &rrr + 0.6875 )
M2, &xstart + &scale * ( &ccc + 0.6875 ), &ystart - &scale * ( &rrr + 0.6875 )
M2, &xstart + &scale * ( &ccc + 0.6875 ), &ystart - &scale * ( &rrr + 0.3125 )
M2, &xstart + &scale * ( &ccc + 0.3125 ), &ystart - &scale * ( &rrr + 0.3125 )
SO,3,0
RETURN
S063: ' entry point for 6.3% square
J2, &xstart + &scale * ( &ccc + 0.4375 ), &ystart - &scale * ( &rrr + 0.4375 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 0.4375 ), &ystart - &scale * ( &rrr + 0.5625 )
M2, &xstart + &scale * ( &ccc + 0.5625 ), &ystart - &scale * ( &rrr + 0.5625 )
M2, &xstart + &scale * ( &ccc + 0.5625 ), &ystart - &scale * ( &rrr + 0.4375 )
M2, &xstart + &scale * ( &ccc + 0.4375 ), &ystart - &scale * ( &rrr + 0.4375 )
SO,3,0
RETURN
X338: ' entry point for 33.8% 'X'
J2, &xstart + &scale * ( &ccc + 0 ), &ystart - &scale * ( &rrr + 0 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 1 ), &ystart - &scale * ( &rrr + 1 )
SO,3,0
J2, &xstart + &scale * ( &ccc + 0 ), &ystart - &scale * ( &rrr + 1 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 1 ), &ystart - &scale * ( &rrr + 0 )
SO,3,0
RETURN
P234: ' entry point for 23.4% 'plus'
J2, &xstart + &scale * ( &ccc + .5 ), &ystart - &scale * ( &rrr + 0 )
SO,3,1
M2, &xstart + &scale * ( &ccc + .5 ), &ystart - &scale * ( &rrr + 1 )
SO,3,0
J2, &xstart + &scale * ( &ccc + 0 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,1
M2, &xstart + &scale * ( &ccc + 1 ), &ystart - &scale * ( &rrr + 0.5 )
SO,3,0
RETURN
‘ THIS IS THE START OF THE ACTUAL DRAWING routine to produce Jim painting -- black layer:
ROW_1: 'nothing in this row
&rrr = 0
ROW_2: ' nothing in this row
&rrr = 1
ROW_3: ' nothing in this row
&rrr = 2
ROW_4: ' nothing in this row
&rrr = 3
ROW_5: ' column 24 is first area to paint
&rrr = 4
&ccc = 24
GOSUB 01 ' draw gestures for gray value = 1 of 0-16
ROW_6:
&rrr = 5
&ccc = 25
GOSUB 07
ROW_7:
&rrr = 6
&ccc = 26
GOSUB 02
&ccc = 144
GOSUB 02
&ccc = 145
GOSUB 04
&ccc = 146
GOSUB 04
&ccc = 147
GOSUB 01
ROW_8:
&rrr = 7
&ccc = 26
GOSUB 10
&ccc = 138
GOSUB 05
&ccc = 139
GOSUB 08
&ccc = 140
GOSUB 11
&ccc = 141
GOSUB 11
&ccc = 142
GOSUB 13
&ccc = 143
GOSUB 15
&ccc = 144
GOSUB 15
&ccc = 145
GOSUB 15
&ccc = 146
GOSUB 15
&ccc = 147
GOSUB 15
&ccc = 148
GOSUB 15
&ccc = 149
GOSUB 14
&ccc = 150
GOSUB 13
&ccc = 151
GOSUB 13
&ccc = 152
GOSUB 13
&ccc = 153
GOSUB 12
&ccc = 154
GOSUB 11
&ccc = 155
GOSUB 06
ROW_9:
&rrr = 8
&ccc = 26
GOSUB 09
&ccc = 27
GOSUB 07
&ccc = 133
GOSUB 02
&ccc = 134
GOSUB 07
&ccc = 135
GOSUB 10
&ccc = 136
GOSUB 13
&ccc = 137
GOSUB 14
&ccc = 138
GOSUB 15
&ccc = 139
GOSUB 14
&ccc = 140
GOSUB 12
&ccc = 141
GOSUB 12
&ccc = 142
GOSUB 10
&ccc = 143
GOSUB 08
&ccc = 144
GOSUB 09
&ccc = 145
GOSUB 09
&ccc = 146
GOSUB 09
&ccc = 147
GOSUB 10
&ccc = 148
GOSUB 11
&ccc = 149
GOSUB 11
&ccc = 150
GOSUB 09
&ccc = 151
GOSUB 12
&ccc = 152
GOSUB 12
&ccc = 153
GOSUB 13
&ccc = 154
GOSUB 13
&ccc = 155
GOSUB 14
&ccc = 156
GOSUB 16
&ccc = 157
GOSUB 12
ROW_10:
&rrr = 9
&ccc = 26
GOSUB 02
&ccc = 27
GOSUB 12
&ccc = 131
GOSUB 05
&ccc = 132
GOSUB 13
&ccc = 133
GOSUB 14
&ccc = 134
GOSUB…
It goes on and on like this – two or three of these commands for each of the 22,000 squares in the drawing – then the next color paints over them, then the next color, and on and on for WEEKS!!!
But it works!!!
-- Mike
¶ 1:39 PM
: 2:26 PMAbout clogging...
Hi, Tom… The airbrush clogging has been mostly resolved now by a) starting with a CLEAN airbrush and b) carefully filtering the ink through a very fine filter paper prior to loading the airbrush. I hope in a week or so to eliminate the problem by using a color formulated for airbrush (currently I’m just using pigmented ink optimized for pens, not airbrushes… I hope that’ll do the trick – the new colors are advertised as “non-clogging” and are also lightfast pigments, so we’ll see… But I am now getting better results and running up to about 15 hours although the line still seems to deform a bit over time… The way the brush works, the paint is sucked by venture into a TINY little cone shaped nozzle with the tip cut off – it’s less than 1/64th inch hole and shallow cone (long and acute angle). A ‘needle’ of the same geometry screws down into this funnel (cone) – when it’s screwed all the way down, it’s a closed valve and no paint can pass – as it’s unscrewed, a tiny passage is formed all the way around and paint can flow – as you continue to unscrew, the passage widens and more paint flows. To make very thin lines, the passage is MINUTE and easy to stop up – which is what still eventually seems to happen. By lowering the air pressure, I can open the valve a bit wider and avoid clogging a bit longer, but this also generates some spatter… So we’ll have to see what happens with the new colors next week!
Thanks for the suggestion! By the way, I’m using an IWATA Revolution SAR (single action airbrush) – I totally admire the precision engineering of this gun – very tiny and very well machined parts, easy to disassemble and clean, and seems reliable and logical – WAY better than anything I can engineer and I have NO way to machine stuff to these close tolerances and small sizes at all! Plus I haven’t been struck by any way to improve the thing – it’s quite ingenious and straight forward and… Well, just very damned cool!
Links to this post:
<< Home
