On this page | |
Since | 19.0 |
This node creates Muscle IDs and assigns them to each connected cluster of primitives on the input geometry. If muscle_id
attributes already exists on the input geometry, then this node also allows you to change the name of the muscle_id
attribute and modify its string values.

Muscle IDs are used by downstream Muscle & Tissue nodes to identify each distinct muscle on the input geometry.
By default, each connected cluster of primitives on your input geometry is assigned an initial temporary Muscle ID value. For example, __piece_0
, __piece_1
, __piece_02
, and so on. You can update your geometry’s Muscle ID values with the Renamings multiparms.
How-to
To... | Do this |
---|---|
Rename a muscle from the viewport state |
|
Rename a muscle from the Parameter Editor |
|
State
Hotkey or Interaction |
Action |
---|---|
= |
Sets the Muscle ID value for the selected muscle. |
- |
Clears the current Muscle ID value for the selected muscle. |
0 |
Clears all the Muscle ID values for the input muscle geometry. |
9 |
Turns on Select Groups or Connected Geometry selection mode and shows the Group and Attribute List in the viewport. |
Visual Feedback |
Meaning |
---|---|
Gray muscle |
Muscle with a default Muscle ID value. |
Gold muscle |
Current selected muscle geometry. |
Red muscle |
Muscle with a renamed Muscle ID value. ![]() |
アトリビュート
|
string |
|
パラメータ
Attribute Name
The name of the Muscle ID attribute the node creates. If you want to define a different name for the Muscle ID attribute, then you can use this parameter to specify a new name for it. For example, you could change muscle_id
to muscle_name
.
Renamings
The Renamings multiparms allow you to specify the muscle geometry pieces you want to rename and the new Muscle ID values you want to assign to them.
Number of Namings
-
The number of muscles. This count does not include the symmetrical muscle duplicates.
-
Adds or removes Renamings multiparms.
1 - Deletes the currently selected multiparm tab.
2 - Inserts a new multiparm tab to the right of the currently selected multiparm tab.
3 - Currently selected mulitparm tab.
4 - Adds or removes multiparm tabs from the end of the list. Increasing the number adds tabs and decreasing the number deletes tabs.
5 - Adds a new multiparm tab to the end of the list.
6 - Removes the multiparm tab from the end of the list.
7 - Deletes all the current multiparm tabs.
Group
Determines which primitive, range of primitives, geometry group, or default @muscle_id to assign the specified Name (Muscle ID value) to. For example, 13929
, 13929-13932
, group_10
, or @muscleid=__piece_01
.
Name
Specifies the muscle_id
string value for the defined Group. If the model for your creature or character is symmetrical, then also include an appropriate prefix (for the left or right side) with the value. For example, L_gastronemius
or l_oblique
.

Mirror Group
For a symmetrical model with Group defined using the @muscle_id
syntax, this field displays the mirror group definition that was automatically determined by the current Symmetry settings. For a symmetrical model with Group defined using a different method, you can use this field to specify the appropriate mirror group definition.
Mirror Group is only accessible when Expose Renaming Parameter is turned on.
Mirror Name
For a symmetrical model with Group defined using the @muscle_id
syntax, this field displays the mirrored Muscle ID value that was automatically generated by the current Symmetry settings. For a symmetrical model with Group defined using a different method, you can use this field to specify the mirrored Muscle ID value.
Mirror Name is only accessible when Expose Renaming Parameter is turned on.

Symmetry
The Symmetry parameters automatically determine and generate Mirror Group and Mirror Name values for the second half of a symmetrical model once you have defined the Group and Name values for the first half.
Automatic symmetry can only occur when you specify your Group values using the @muscle_id
syntax. If you use any other method (like range of primitives or geometry group), then you will need to enter your muscles' Mirror Group and Mirror Name values manually.
Automatic symmetry is only applicable to whole intact symmetrical models. If your input muscle geometry is only one half of a symmetrical model, then you can use the Mirror Muscles SOP downstream in your Muscles & Tissue network to make sure that all your muscles are assigned the appropriate Muscle ID values.
Apply Symmetry
When on, if you have a full intact symmetrical model (not just one half a model), then when you use Group and Name to name your muscles, the muscles on the other side of the model will automatically be named using the rules defined by the Mirror Parameters settings.
Symmetry does not work when the Group parameter contains primitives or a range of primitives. It only works when it contains groups that you set-up upstream using one of the Group SOP nodes.
The Mirror Parameters are only available when Apply Symmetry is on.
Expose Renaming Parameter
When on, the Mirror Group and Mirror Name parameters appear in each Renamings multiparm.
From Prefix
Specifies the name prefix that is used for the Name value. For example, this parameter value would be L_
if your Name values are L_gastronemius
, or L_oblique
, and so on.
To Prefix
Specifies the name prefix that will replace the From Prefix in all of the automatically generated Mirror Name values. For example, if the parameter value for From Prefix is L_
, then your To Prefix parameter value should be R_
for R_gastronemius
, or R_oblique
, and so on.
Origin
Origin of the mirror plane.
Distance
Distance of the mirror plane.
Direction
Normal direction of the mirror plane.
入力
-
Ideally non-intersecting polygonal manifold geometry for your muscles.
-
The muscle geometry data could come from a variety of sources.
For example:
-
Geometry SOP nodes located in the same HIP file as your Muscle & Tissue network.
-
Stash SOP node containing the muscle geometry data.
-
Alembic SOP node that loads in an
.abc
file that contains the muscle geometry data. -
File SOP that references a
.bgeo
on disk that contains the muscle geometry data.
-
出力
muscle_id
s for each connected cluster of primitives that represents a muscle in your Muscle & Tissue network.
See also |