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Introduction

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This script is not extremely difficult to understand and use but it's not a trivial affair.

This script lets you create dynamic looking animations, a common use may be breast bounces as a figure dances

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History

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2019 December 16th 03:53 PM - repaired the Load function

2017 May 29th 11:23PM - added a "delay" option to the translators panel

2017 May 29th 11:23PM - corrected an issue with the "modify" button of the translators panel

2017 April 8th 2017 - corrected a bug at line inCtl = obj.findModifier( inName ); needed to be inCtl = obj.findModifier( inPropName );

2016 October 10th 2016 - release

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Installation

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The zip package is found at the bottom of this page

unzip it in your daz content folder, typically

C:\Program Files\DAZ\Studio\content\

or

C:\Program Files (x86)\DAZ\Studio\content\

once installed, it will appear in your content library, under Studio / Scripts / mcasual

or

C:\Users\Public\Documents\My DAZ 3D Library\

once installed, it will appear in your content library, under My DAZ 3D Library / Scripts / mcasual

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Use

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Phase 1

The first phase is to create a "simulator device"

A simulator device is composed of 2 nodes

there's the simulator base which will be parented to your actor

and there's the simulator sim which will be parented to the simulator base

if you "run the simulation", the script will animate the sim position for each frame of the current timeline play-range

The sim will swing just as if it was attached to the base using a rubber band.

Hands-on test:

Animate Aiko 4 over a 30-frames playrange.

I used one of the dance loops from my site: https://sites.google.com/site/mcasualsdazscripts2/mcj-2

then i added abdomen swings and hip hoppings

Select Aiko4's chest node

Launch mcjElasticSim

Go in the "Simulators" tab

here you can see we decided to call the simulator device ChestSimDev

i wanted the simulator in the center so i set x = 0

i wanted the simulator in front of the chest, so i set z = 16

y is set to 8, so the base it right in front if the breasts

the other 12 parameters will constrain the simulation movement, but for now, we leave it as-is.

Click on the "Add" button

a simulation device should appear in front of the chest ( shown below as red/green/blue cross )

Click on the Run Simulation button

That's it, for each frame of the timeline playrange, the script animated the sim and it now swings around the base

Since we have a dance loop here, we can click on the Run Oversim button a few times

The script recycles the position of the sim at the end of the playrange, this improves the loopingness of the sim node animation.

Here you see the X and Y animation curves of the sim ( viewed using my mcjSceneGraf plugin )

you will notice that the curves are constrained in the -4 to 4 ( centimeters ) range

That was the purpose of the minX, maxX, minY, maxY, minZ, maxZ parameters we saw previously

the Y curve shows signs that it's hitting the minY floor very hard, this won't look good

so i change minY to -10

i click the "Modify" button and i re-run the simulation

now you can see our sim swings between -9.5 and -1.3 so it never "hits" a floor nor a ceiling

Note that my mcjCycleFilter script is another tool which lets you inspect and modify animation curves

Phase 2

Using "translators" we will convert the movements of the sim into movements of the actor body.

Hands-on test:

Since we "hanged" our simulator device right in front of the chest of our actress,

we can transform the movement of the sim, into movements of the breasts

A translator is simply a set of factors, a source property and a destination property

If mcjElasticSim is still running, press the Exit button

The breast morphs are attached to the root node of the Aiko4 figure, so, select Aiko 4

Now, and this is a bit annoying, but for the sake of versatility, you must also select the source of the movement

in our case it means the sim node ( not the base node! ) named ChestSimDev

Start mcjElasticSim

you will notice that mcjElasticSim detected the presence of the simulator device we created earlier

Go in the Translators tab

the source movements for our translator is the ChestSimDev's YTranslate property

the destination is Aiko4's PBMBreastUpR morph

when the source moves up and down between -9.5 and -1.3

we want the BreastUp morph to swing between -0.5 and 0.4

Next, and this is easy to forget, click on the "Add" button and the settings will appear in the table.

Then, click on the "Sim to Morph" button, and the movements of the sim will be translated into movements of the PBMBreastUpR morph

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Things we did not cover so far and a few tricks of the trade

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Trick: set the timeline framerate at 120 fps, create your simulation, set the timeline back to 30 fps. This sometimes improves the results.

Trick: The simulator parameters discussed here correspond to a channel in the parameter tab of the sim.

Trick Change simulation parameters only when you are at frame 0 of the timeline to avoid creating unmanageable animated parameters.

Simulator Tab

As we mentioned, minX, maxX, minY, maxY, minZ, maxZ limit the movements of the sim. The default is 4cm. in Many cases you may want to increase this.

vMax is the maximum speed the sim is allowed to travel per frame, the default is 10

aMax is the maximum acceleration the sim is allowed to achieve, the default is 400

stiff is the stiffness of the imaginary rubberband that goes from the base and the sim the default is 10. You could call this the Hooke spring constant.

here is the same simulation with a stiff factor of 1000 instead of 10

i was a bit surprised that i needed to change it that much to get clearly visible differences

damp stands for "damping", if damp is 1.0 it means 100% of the energy is carried along for each frame of the animation.

If our actress jumped even just 1 time, her breasts would bounce up and down forever.

using a damp value of 0.95 means only 95% of the energy is carried along each grame of the animation

so if the actress stands still, the movements will eventually die down.

here is our simulation with stiff = 10 and damp = 0.98

xAcc yAcc and zAcc is the 3 dimentional force acting on our imaginary weight

we have yAcc = -980, but the x and z components are null, this represents gravity on Earth, 980 cm/s²

changing this should change the apparent weight of the simulator mass.

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Someday i'll add other examples

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if you use mcjElasticSim's WebHelp button you will be sent right here,

and be able to see if i posed bug-fixed versions and improvements

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Example for Genesis3

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a moderately not-too-bad result was obtaines using

the default simulator settings, but the simulator device is attached to the lower-chest node

the position is x,y,z = 0, 8, 20

For the translator, the settings are

source node : simulator001

source property: YTranslate

source min : -4

source max : 0

destination node : Genesis3Female/Zephyra

destination property: pCTRLBreastsUp-Down

destination min : -1

destination max: 1

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Perfecting the Genesis3 simulation

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This is the up-down movement of the sim node ( inspected using my mcjCycleFilter script )

we immediatety see that the lower limit of -4 is way too high, the breasts hit an invisible floor

so we'll try something, we'll set it to -1000000

... way better

and here you can see the XTranslate movement

the small kink in the curve is due to a dance-animation defect

i then set the xMin and xMax limits at -4000 to 4000 and re-ran the simulation

, the simulated range is -4.75 to 4.5 instead of -4 to 4, so there's a bit less "hitting a wall" effects

also note that i constrained to sim's zMin/zMax to 0 .... so the sim moves in a flat X-Y plane

i then tested different simulation settings until i liked the resulting simulation curves

here you see i basically removed the min/max position limits by setting them to -4000/4000

i reduced the damping to 0.94

i also ran the simulation at 60 frames per second

here you see the sim now swings left-right -2.2 to 2 and up-down -6.7 to 3

we manually activate the breast-up morph and determine that the range should be -0.67 to 0.67 ( in the parameters tab it reads as -67% yto 67% )

for the horizontal movements of the sim we will be activating the Breasts Side-Side morphs between -0.67 and 0.67

so we select Genesis3 then add the sim ( the mobile part of it ) to the selection

we run mcjElastic sim

we go in the Tranlate table

and create these settings

notice how the -2 to 2 left-right movements translate to +0.67 to -0.67 Breasts Left-Right morph strengths

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NEW IN THE MAY 29th 2017 VERSION - Delay and/or Loop

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The translator panel now includes a "Delay" option

when this delay is not zero the property values will be copied from the source property to the target property with a delay expressed in frame

There's also a "looping" option,

when the looping option is in effect, the keyframes that fall out of the PlayRange window will be placed at the beginning of the playrange

so if the source property was looping/cyclical, the delayed target property will also be looping/cyclical

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License

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by mCasual/Jacques

Copyright (c) 2015 <mCasual/Jacques>

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files ( mcjAutoLimb2014 ), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

// THE SOFTWARE.