I have a question about the hammer setting of the Scanned opcode scanu(2).

Looking at the manual (as i always am), i think there are 5 settings that have an influence when the scanu opcode is set to 'hammer' mode:

1. set init to negative table --> set to hammer mode

2. ileft pluck has influence

3. iright pluck has influence

4. kposition has influence

5. kdisplace has influence.

If the hammer option is not set, all these arguments should not have any influence on the sound. Am i correct?

However

kdisplace always has an influence on the sounding result, even when not in hammer mode. Should this be so?

Manual says: kdisplace -- power that the active hammer uses.

so i assume this kdisplace should only have an effect if init is in negative mode (=hammer).

Or else we should change the text in the manual?

Here is a slightly adapted example from the manual page GEN44 that shows this:

<CsoundSynthesizer>
<CsInstruments>
sr=44100
ksmps=32
nchnls=2
0dbfs  = 1

instr scan ;
a0 init 0
irate = .01
kmass line 2,p3,5
kstiff line 30,p3,45
kcenter line .08,p3,.01
kdamp line .01,p3,.08
kpos line 0,p3,16

;scanu2 init,irate,ifndisplace,ifnmass,ifnmatrix,ifncentr,ifndamp,kmass,kmtrxstiff,
; kcentr, kdamp, ileft, iright, kpos, kdisplace, ain, idisp, id
scanu2 p6, irate, 6, 2, 3, 4, 5, kmass, kstiff, kcenter, kdamp, .2, .7, kpos, p7, a0, 1, 2
;ar scans kamp, kfreq, ifntraj, id
a1 scans ampdbfs(p4), cpspch(p5), 7, 2
a1 dcblock2 a1
outs a1, a1

endin

</CsInstruments>
<CsScore>
f1 0 16 10 1         ; sine hammer
f2 0 16 -7 1 16 1    ; Masses
f3 0 0 -44 "/media/datae/CsoundManual7/manual-7.0/examples/string_with_extras-16.matrxT"   ; Spring matrices
f4 0 16 -7 1 16 1    ; Centering force, uniform initial centering
f5 0 16 -7 1 16 1    ; Damping, uniform damping
f6 0 16 -7 .01 16 .01 ; uniform initial velocity-displacement
f7 0 16 -5 .001 16 16 ; Trajectories

i"scan" 0 2 -6 7.00 -1  0       ; hammer & power to 0
i"scan" 3 2 -6 7.00 1   0       ; normal mode & hammer power at 0

i"scan" 6 2 -6 7.00 -1  .5      ; hammer & power to .5
i"scan" 9 2 -6 7.00 1   .5      ; no hammer & but power to .5 ; still influence??

e
</CsScore>
</CsoundSynthesizer>

First - about the metaphor of a HAMMER

I agree that the idea of calling it a 'hammer' might not be the best metaphor.

- for instance, if you have a surface, it would be like you are displacing the surface with a shape (like a rock)

- and hammer implies that you are striking it - but you are actually initializing a deformation of the surface and then setting it in motion - according to all the other parameters

===

I think that more correct words are topography. (for the overall shape) - and then a contour line 

====

The word used to describe the contour of a terrain is topography:

 
Topography: The study of the shape of the land's surface, including its ups and downs. The word comes from the Greek words topo, meaning place, and graphia, meaning to write or to record.

 
Topographic map: A map that uses contour lines, colors, and shading to represent the shape of the terrain and changes in elevation.

 
Topographic contours: Lines that connect points on a map that represent the same elevation.

 ===

SECOND - inits are initial states of the system

THIRD - krate variables for most INITS

while the 'system' is evolving, the k-variable allow one to alter the system (with MIDI controllers or functions or offsets) 

- essentially the allow one to dynamically override or influence the natural evolution

- and so to me - if you had an initial "hammer" (template/mold/shape/contour/terrain/topography) or not, kdisp would still influence the sound

0 for p7 would only mean that you are not doing any scaling/biasing of the system or any continuous control of the system

BUT note...

You have an initial displacement table that (over p3) is currently not displacing the system, but it could - with or without a "hammer"

PS - I have not had time to fully review (and use) your fantastic and detailed document and system for scanned in Blue - but WOW... that is awesome work.

- it would have been great for you to have presented this at the ICSC

- you ABSOLUTELY need to present it at the next ICSC (and get all sorts of feedback - especially from Victor)

I will see John again this morning - and I will ask him about this displacement issue - to see if what I am telling you gels with what he remembers about the code.

 

PPS - also (as I am sure you know) your matrix in this example makes a circular string

- Dr.B

Dr. Richard Boulanger

Professor

Electronic Production and Design

Berklee College of Music

Professional Writing & Technology Division

On Mon, Sep 30, 2024 at 7:29 AM tjingboem <magknevel@gmail.com> wrote:

I have a question about the hammer setting of the Scanned opcode scanu(2).

Looking at the manual (as i always am), i think there are 5 settings that have an influence when the scanu opcode is set to 'hammer' mode:

1. set init to negative table --> set to hammer mode

2. ileft pluck has influence

3. iright pluck has influence

4. kposition has influence

5. kdisplace has influence.

If the hammer option is not set, all these arguments should not have any influence on the sound. Am i correct?

However

kdisplace always has an influence on the sounding result, even when not in hammer mode. Should this be so?

Manual says: kdisplace -- power that the active hammer uses.

so i assume this kdisplace should only have an effect if init is in negative mode (=hammer).

Or else we should change the text in the manual?

Here is a slightly adapted example from the manual page GEN44 that shows this:

<CsoundSynthesizer>
<CsInstruments>
sr=44100
ksmps=32
nchnls=2
0dbfs  = 1

instr scan ;
a0 init 0
irate = .01
kmass line 2,p3,5
kstiff line 30,p3,45
kcenter line .08,p3,.01
kdamp line .01,p3,.08
kpos line 0,p3,16

;scanu2 init,irate,ifndisplace,ifnmass,ifnmatrix,ifncentr,ifndamp,kmass,kmtrxstiff,
; kcentr, kdamp, ileft, iright, kpos, kdisplace, ain, idisp, id
scanu2 p6, irate, 6, 2, 3, 4, 5, kmass, kstiff, kcenter, kdamp, .2, .7, kpos, p7, a0, 1, 2
;ar scans kamp, kfreq, ifntraj, id
a1 scans ampdbfs(p4), cpspch(p5), 7, 2
a1 dcblock2 a1
outs a1, a1

endin

</CsInstruments>
<CsScore>
f1 0 16 10 1         ; sine hammer
f2 0 16 -7 1 16 1    ; Masses
f3 0 0 -44 "/media/datae/CsoundManual7/manual-7.0/examples/string_with_extras-16.matrxT"   ; Spring matrices
f4 0 16 -7 1 16 1    ; Centering force, uniform initial centering
f5 0 16 -7 1 16 1    ; Damping, uniform damping
f6 0 16 -7 .01 16 .01 ; uniform initial velocity-displacement
f7 0 16 -5 .001 16 16 ; Trajectories

i"scan" 0 2 -6 7.00 -1  0       ; hammer & power to 0
i"scan" 3 2 -6 7.00 1   0       ; normal mode & hammer power at 0

i"scan" 6 2 -6 7.00 -1  .5      ; hammer & power to .5
i"scan" 9 2 -6 7.00 1   .5      ; no hammer & but power to .5 ; still influence??

e
</CsScore>
</CsoundSynthesizer>