Physics setting

(Updated 08/19/2021)

 

What is physics calculation?

With Cubism, you can set up and export physics calculations that will create hair swaying movements in real time as the face turns around.

This page describes the [Physics] settings in the [Physics Computation and Scene Blend Settings] dialog box.
For details on
how to set up physics operations, please refer to “How to Set Up Physics Operations”.
Physics can be set from the [Modeling] menu -> [Open Physics/Scene Blending Settings].

* As there is also a [Scene Blend] tab in the [Physical Computation/Scene Blend Settings] section,
 please make sure that the [Physics] tab is selected.

 

Screen Structure of Physics Setup

Number Item Detail
(1) Menu This is a menu item in the [PHYSICS/SCENE BLEND SETTINGS] dialog box.
See “Physics and Scene Blending Settings” for details.
(2) Playback bar
View area

Playback of playlists set in scene blending, fades during scene transitions, and FPS settings can be made.
See “Physics and Scene Blending Settings” for details.

(3) Group Settings Settings for physics operations added to the model are handled on a group basis.
Groups can be created for each part of the body to be shaken, such as “swinging bangs” and “swinging skirt”.
(4) Input settings This item is used to set parameters to be treated as inputs for physical operations.
This sets up the “part that suspends the thread” of the pendulum.
The degree of influence of the parameters specified here will vary, affecting the value of the [Output Settings] described below.
(5) Output setting This item is used to configure settings for outputting calculated shaking.
(6) Physical Model Setting This item is used to set the way the camera shakes when it is actually moved.
This is the setting for the “weight” of the pendulum.
This item is used for calculations based on changes in the values of the parameters set in the [INPUT SETTINGS].
(7) Pendulum Preview The results calculated in the [Input Settings] and [Physical Model Settings] are previewed as the pendulum's motion.

 

Group Settings

Item Detail
Group Select the group for which you want to perform [Input Settings], [Output Settings], and [Physical Model Settings].
Validity Checking this box temporarily toggles the enable/disable of physics operations for the currently selected group.
It does not affect the export of the physics setup file.
All of these enable flags are reset when the Physics and Scene Blend Settings dialog is closed.
Add Create and add a new group.
Duplication Duplicates the currently selected group.
Group Editing Edit each group.

 

Input settings

Input Preset

The [Input] preset settings, in which [Input], [Type], and [Influence] are set in advance, can be read and the [Input Settings] can be set instantly.
You can also save
your own settings as presets for future use.

Item Detail
Name

Select a saved preset.
Three types of inputs are available by default: “head input,” “torso input,” and “chest input”.

Read in Loads the selected preset.
Add Add the current settings as a preset.
Overwrite save Overwrites and saves the current settings to the selected preset.
Name change Rename the selected preset.
Delete Deletes the selected preset.

 

Input setting items

Item Detail
Add Add a parameter to be treated as an [input].
Delete Deletes the selected [Input] parameter.
Moves the position of the selected [Input] parameter up one position.
Moves the position of the selected [Input] parameter down one position.
Input This parameter is treated as an [input].
Changes in the value of this parameter will cause fluctuations in the parameters set for [Output].
Parameters can also be changed from the pull-down menu.
Classification

Sets how changes in the value of a set parameter are treated as movement.
Position X: Treat as lateral movement
Angle: Treat as a tilt in the Z-axis direction

Impact (%)

When multiple parameters are set as [Inputs], you can set which [Inputs] affect what percentage of the total.
If there are multiple parameters of the same [Type] in the same group, the parameter with the larger value is more affected.

* The influence of the same [Type] cannot be set to more than “100%” in total.
 For different types, each can be set to a maximum of 100%.

Reflect Checking the box inverts the + and - for the [Input] parameter.
Use to invert [Input].

 

Input normalization

The adjustment is made to allow the hair to hang straight down and rest against gravity as the head and other parts of the body are tilted.
Because the “head” and “body” tilts set on the model are at different angles on each model,
normalizing the angle input, if necessary, can improve quality.
(For the position, the default value is fine as it is used for special models.)

Item Detail
Angle Angle normalization can be set.
[Minimum], [Center], and [Maximum] are set to [-10.0] to [0.0] to [10.0] by default.
This value can be changed at will.
Position X Position normalization can be set.
[Minimum], [Center], and [Maximum] are set to [-10.0] to [0.0] to [10.0] by default.
This value can be changed at will.

The general model is roughly normalized with the defaults, but
if you want to fine-tune the model, try adjusting the normalization.

 

On the value of “angle” normalization

The process of converting the minimum and maximum definitions of the parameters specified in the input to the minimum to maximum range specified in the input normalization is called input normalization.
(The center is converted so that the value halfway between the smallest and largest parameter definition is the center of normalization.)

Among the normalized value of each parameter, for those that have the type as [Angle],
one value blended with the degree of influence is reflected as the angle of the uppermost pendulum.

 

Physical Model Setting

Physical Model Presets

The [Physical Model] preset settings, where Duration], [Shakability], [Reaction Speed], and [Overall Speed] are pre-set, can be loaded to instantly configure the physical model settings.
Settings created by the user can be saved and used as presets.

Item Detail
Name Select a saved preset.
Reading Loads the selected preset.
Add Add the current settings as a preset.
Overwrite save Overwrites and saves the current settings to the selected preset.
Name change Rename the selected preset.
Delete Deletes the selected preset.

 

Physical model setting items

Item Detail
Add Add a new pendulum.
Delete Deletes the selected pendulum.
Moves the selected pendulum one position up.
Moves the selected pendulum one position down.
No When the pendulum is set to a multi-stage setting, the numbers are assigned from the top to the bottom.
This number is used in [Output Settings] described below.
Duration You can set the speed of shaking.
The smaller the value, the quicker the movement; the larger the value, the slower the shaking.
If you want to change only the speed without changing the amount of change in the parameter value, adjust the [Reaction Speed] item.
Shakiness You can set the magnitude of the shaking.
The larger the value, the larger the swing will be for even a small input.
As a rule of thumb, use a setting in the range of 0.7 to 0.99.
Reaction velocity You can set the reaction speed of the shaking.
This is a setting for how agilely it responds to input.
The response is equal at “1”; greater than “1” makes it more agile, and less than “1” makes it less responsive.
If the pendulum is multi-staged, the setting is based on how agile the child pendulum is in response to the movements of the parent pendulum.
Speed of convergence You can set how quickly the shaking stops.
The convergence is equal at “1”. If it is greater than “1”, the convergence is faster, and if it is less than “1”, the convergence is slower.

 

 

Pendulum Preview

Item Detail
Preview Preview the pendulum's original motion as calculated on the [Physical Model Settings].
However, the influence set in [Input Settings] and [Output Settings] is not reflected in the pendulum.
Click [Add] in the pendulum settings to add a pendulum downward.
The scale can be adjusted by operating the mouse wheel on the preview.
Full Scale Displays the preview in full size.
Whole Displays the entire pendulum.
Rotate left/right The preview angle is rotated by 45 degrees.
The angle changed here does not affect the way the pendulum swings.

 

 

Right-click menu

Right-clicking on an item displays a menu that allows you to [Add] or [Delete] the item.
Multiple items can be selected, so they can be deleted in batches.

 

Output setting

Output setting items

Item Detail
Add Add a parameter to be treated as an [output].
Delete Deletes the selected [Output] parameter.
Moves the position of the selected [Output] parameter up one position.
Moves the position of the selected [Output] parameter down one position.
Maximum output automatically updated Unchecking this checkbox stops the automatic update of [Maximum Output (%)].
Pendulum No. Specifies which of the pendulums set in [PHYSICAL MODEL SETTINGS] will be used for output.
Output This parameter is handled as [Output].
The shaking calculated from the settings of each item is applied to the set parameters.
Parameters can also be changed from the pull-down menu.
Impact (%) Cubism's physics operations allow multiple parameters to be entered.
When outputting the results of multiple physical operations to parameter values, this item sets which outputs will affect the ratio of what to what.
Reflect When checked, output parameters are inverted.
Scale The value to multiply the calculated value by.
The larger this value, the greater the shaking, and the smaller the value, the smaller the shaking.
Maximum output (%) The maximum output (%) indicates the percentage by which the output value of the result of multiplying moved from 0 to the maximum value of the destination parameter.
Output adjustment (up) If [Maximum Output] does not reach 100% and the pendulum movement is small, the magnification is automatically adjusted so that [Maximum Output] reaches 100%.
Output adjustment (down) If [Maximum Output] is greater than 100% and the pendulum is swinging out of control, the magnification is automatically adjusted so that [Maximum Output] is set to 100%.
Reset Magnification Reset [Scale] to 1.0.
Reset maximum output Resets the [maximum output].

TIPS
The magnification is obtained by taking the angle of the pendulum (relative to the parent pendulum) specified by the pendulum No. as a radian
and radian and multiplying it by this magnification.
It then blends that value with the current parameter value, taking into account the degree of influence. (Overwrite if 100%)
(If multiple groups are defined so that the same parameters are affected, repeat the above calculations in the order of the groups.)

 

Right-click menu

Item Detail
Add Add output items.
Separate as a group in a batch Creates a new group containing all currently selected output settings.
Input setting items are also duplicated.
Separate as individual groups Create a new group for each of the currently selected output settings.
Input setting items are also duplicated.
Delete Delete output items.
Multiple selections can also be deleted.
Copy Copy output items.
Multiple selections can also be copied.
Paste Paste the copied output items.
It can also be pasted to other groups.

 

 

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