Duplicate Along A Path?

[sh4dow]

hi

i keep coming back to this problem... duplicating objects along a path... i know that it works in 3dsmax but i just can't find a way to do that in maya. so what if i want to position objects along a spring? or some other random curve? and i'm not talking about 3 or 4 which you could position manually...
is there a way to do that in maya?

[joojaa]

sure make a path anim and doa animated snapshot.

heres a demo scene of 100 balls stringed along a curve (copypaste into script editor and execute, please note it clears the sccene!):

CODE
file -f -new;
curve -d 3 -p 3.892044 0 11.928491 -p 0.760851 0 9.510984
     -p 5.413507 0 8.540187 -p 7.196644 0 6.41965
     -p 4.361209 0 1.610677 -p -0.746363 0 -0.746363
     -p -7.843118 0 1.12856 -p -11.852348 0 -3.396846
     -p -8.055934 0 -8.255295 -p 0.0532774 0 -7.747131
     -p 4.872444 0 -3.023954 -p 8.894003 0 0.427104
     -p 10.31592 0 -1.814466 -p 8.004217 0 -6.903244
     -p 6.135196 0 -10.071409 -p -0.138394 0 -15.815572
     -p -5.246888 0 -16.641558 -p -7.825661 0 -15.744865
     -p -12.216692 0 -12.88232 -p -15.724947 0 -8.276756
     -p -20.706092 0 -4.61577 -p -18.803884 0 -0.682574
     -p -14.393294 0 3.42995 -p -8.843161 0 7.817395
     -p -5.018732 0 11.443837 -p -5.23224 0 14.39145
     -p -5.143224 0 14.464331 -k -2 -k -1 -k 0 -k 1
     -k 2 -k 3 -k 4 -k 5 -k 6 -k 7 -k 8 -k 9 -k 10
     -k 11 -k 12 -k 13 -k 14  -k 15 -k 16 -k 17 -k 18
     -k 19 -k 20 -k 21 -k 22 -k 23 -k 24 -k 25 -k 26;
sphere -p 0 1 0 -ax 0 1 0 -ssw 0 -esw 360 -r 1 -d 3 -ut 0
      -tol 0.01 -s 8 -nsp 4 -ch 1;
select -allDagObjects;
pathAnimation -fractionMode true -follow true -followAxis z -upAxis y
             -worldUpType "scene" -inverseUp false -inverseFront false
             -bank false -startTimeU 0 -endTimeU  100;
snapshot  -increment 1 -constructionHistory 0 -startTime 1
         -endTime 100;
delete;

Ps do you need the distributed objects connected to the curve for animation? Because that too is possible.

[sh4dow]

thanks a lot

[safarisister]

QUOTE(sh4dow @ 01/12/06, 01:53 AM)
hi

i keep coming back to this problem... duplicating objects along a path... i know that it works in 3dsmax but i just can't find a way to do that in maya. so what if i want to position objects along a spring? or some other random curve? and i'm not talking about 3 or 4 which you could position manually...
is there a way to do that in maya?
[snapback]224691[/snapback]

Hi there, i had the exact same frustration on duplicating objects along a curve (path to 3DS folks)...i had 5 engineers at one point looking over my shoulder trying to help me figure this one out in Maya when i first started working with this tool. Then i met Adrian Herbst, he teaches a Mel Scripting class at The Academy of Art in San Francisco. He turned me on to the script below...but if there's several other ways i've seen folks address this..also check out

http://forums.cgsociety.org/printthread.php?t=121358

I havent' taken a scripting class yet but i do know enough now to poke around and edit other scripts which i'm beginning to see as a whole unique feature set in Maya.
As given to me from Adrian...this script allows objects to be duplicated along a curve. To use, select the object, shift-select the curve, and after applying settings, click the button.

good luck

Jacky Powell
safarisister.com

copy and paste into text file named alongCurve.mel

---------copy & paste starting with next line -----------
global proc alongCurve ()
{
string $winName = window -title "Duplicate Along Curve" ;
columnLayout;

text -label "Number of items to create";
intField number;

text -label "Follow Axis"; 
radioButtonGrp -numberOfRadioButtons 3 
	-labelArray3 "X" "Y" "Z" axis;

text -label "Up Axis"; 
radioButtonGrp -numberOfRadioButtons 3 
	-labelArray3 "X" "Y" "Z" axis2;


button -label "Create Objects" -command "makeDupes()";

showWindow $winName;

}

global proc makeDupes()
{
int $number = intField -q -v number;
if ($number < 2) $number = 1;
float $increment = 1/((float)$number-1);

int $whichAx = ` radioButtonGrp -query  -sl axis`; 
string $axis;

switch ($whichAx)
{
case 1:
	$axis = "x";
	break;
case 2:
	$axis = "y";
	break;
case 3: 
	$axis = "z";
	break;
default:
	$axis = "x";
	break;
}

int $upAxis = ` radioButtonGrp -q -sl axis2 `;
string $ax2;

switch ($upAxis)
{
case 1:
	$ax2 = "x";
	break;
case 2:
	$ax2 = "y";
	break;
case 3: 
	$ax2 = "z";
	break;
default:
	$ax2 = "y";
	break;
}			

string $sel[] = ` ls -sl `;

string $newObj[] ;
string $motionPath ;

for ($i=0 ; $i<$number ; $i++)
{
	select $sel[0] ;
	duplicate -rr ;
	select -tgl $sel[1];
	$motionPath = ` pathAnimation -followAxis $axis -upAxis $ax2 -fractionMode true ` ;
	CBdeleteConnection ($motionPath+".u");
	setAttr ($motionPath+".uValue") ($i*$increment);
	delete $motionPath; 
}

}
--------end of script - do not include this line in your copy & paste-------------

Here's a quick and easy way that someone from the cgtalk.com posted...
1) create the curve
2) snap the object to the end of the curve.
3) Select your object, shift select the curve, Animate - Motions Paths - Attach to Motion paths.
(Now if u hit play, your object show move along the curve)
4) Select your object, Animate - Create Animation Snapshot
(In the options, u can change the increments, frame range etc)

[joojaa]

I must say you have had pretty stupid eingeneers. (who either didnt knwo how to perate maya, alternatively they had private fun on you)

again it quantizes the problem to the same thing as above just builds a nice gui for you! Okay so iyts computationaly worse then what i said (it uses a for loop and many path anim curves wich is considerably slower).

mel is often a self delusion for artists in this sense. If you can do it in 2 clicks why build a gui that can do it in 3? Wich can heppen when pople wants the exact same tool. Not the ideal idea.

The idea here is to do a animate snapshot of a curve anim mel or no mel! If you cant decipher the idea then you cant do it in mel wery well. Anyway doing it manualy soon makes you realize you can easily do a nonuinform distribution aswell. with 2 more click and scale it using agraphg with 2 more and morph it along the path, randomize its shape in with 4 and so on.

Theres a faster way to iterate this tough, especialy if you want instances of complex objects.

The reason theres no tool for this in maya is because its so ballantly simple to do with 2 tools that gives you 100 times the flexibility, i whit out STUPIDIFYING the end user.

[safarisister]

I'm STUPIDIFied...what did you just say :]

[joojaa]

That you have missed the point. Following sums it all:

QUOTE(Joojaa @ 01/12/06, 12:12 PM) [snapback]224693[/snapback]
sure make a path anim and do a animated snapshot.

this is same as saying:

animateMenuset| Animate -> Motion Paths -> Attach to Motion Path
animateMenuset| Animate -> Create Animation Snapshot

a simple straightforward 2 command combo, learn this one and you'll understand why maya is MISSING so much functionality, because its not they are just split to 2 basic operations that can be used independently. so a 2 command combo is very common in maya (this effectively gives maya faculty(nuberOfcommands*2))

But this is actually more effective than your code is essentially these 2 commends do the same as your creation loop:
CODE

for ($i=0; $i<$number; $i++)
{
select $sel[0];
duplicate -rr;
select -tgl $sel[1];
$motionPath = `pathAnimation -followAxis $axis -upAxis $ax2 -fractionMode true`;
CBdeleteConnection ($motionPath+".u");
setAttr ($motionPath+".uValue") ($i*$increment);
delete $motionPath;
}

Except its far more efficient tuuthfully its closer to this piece of code but since its done in api its 100 times faster anyway (but even this is better code if you want to split hairs), but speed is largely irrelevant unless you copy millions of these objects:

CODE
$motionPath = pathAnimation -followAxis $axis -upAxis $ax2 -fractionMode true $sel[0] $sel[1];
CBdeleteConnection ($motionPath+".u");  
for ($i=0; $i<$number; $i++)
{
setAttr ($motionPath+".uValue") ($i*$increment);
duplicate -rr;
}
//delete $motionPath;

Now as for why you should know the animated snapshot method is ovious, you have final say so of how things proceed, so you could have nonuniform placement as easily as a uniform one. Have different scales shapes etc etc. by holding between step 1 and 2 your options increase to million fold.

heres a example of alternating scale:
CODE

{
file -f -new;
$circ=circle -c 0 0 0 -nr 0 1 0 -sw 360
       -r 2 -d 3 -ut 0 -tol 0.01 -s 8 -ch 1;  
$sph=sphere -p 0 0 0 -ax 0 1 0 -ssw 0 -esw 360  
       -r 0.1 -d 3 -ut 0 -tol 0.01 -s 8 -nsp 4 -ch 1;
pathAnimation -fractionMode true -follow true -followAxis x  
              -upAxis y -worldUpType "normal" -inverseUp false  
              -inverseFront false -bank false  
              -startTimeU 1 -endTimeU 51  $sph[0] $circ[0]; //50 copies
setKeyframe "nurbsSphere1.sy";
currentTime 1;
setAttr "nurbsSphere1.scaleY" 2;
setKeyframe "nurbsSphere1.sy";
currentTime 2;
setAttr "nurbsSphere1.scaleY" 1;
setKeyframe "nurbsSphere1.sy";
selectKey -add -k -t 0 -t 1 nurbsSphere1_scaleY;
setInfinity -poi cycle;
snapshot  -increment 1 -constructionHistory 0  
          -startTime 1 -endTime 50 -update animCurve;
delete $sph[0];
}

yeah i know it spits a cycle check. ignore it.