Determines which main constraint properties are currently being displayed in the node’s viewport state. Clicking on a button will also select the relevant tab.

When on, shows the node’s second input in the viewport state. Bones are only displayed if you provide them as the second input.

When off, End Regions will be proportional to the computed length of a given muscle. The computed length of a muscle will be stored in the musclelength point attribute. If the musclelength attribute already exists, it will be used instead of being computed. When this parameter is on, End Regions disregards musclelength, and the muscle end mask values are measured in world units. Muscle Ends use the axialramp attribute to determine the extents of individual muscles.

When on, the axialramp attribute will tend to be more sensible about which way is up. This will affect the correlation between the Muscle End Radius parameters, and the orientation of the affected muscles. When off, this orientation can appear somewhat arbitrary. The axialramp attribute will only be computed if it doesn’t already exist. Therefore, this toggle will only have an effect when the incoming muscle geometry does not have an axialramp.

When off, masks created by this node are allowed to be non-zero on interior tet points.

Use the Property Label if it is specified, otherwise the Group to label the the multiparm tabs. Any occurance of @muscle_id= will be stripped. Uses numbers instead when off.

Strips anything preceding the first underscore from the label, if multiparm labels are enabled. This is useful for removing prefixes such as L_ from the label when only dealing with one side.

The number of defined muscle property setting assignments. Adds or removes a Property Assignment multiparm.

Property Assignment multiparm tabs

• A single multiparm tab can define the muscle property settings for a single muscle or multiple muscles (muscle_ids). See Group.

• A single muscle can appear on multiple multiparm tabs.

• Each multiparm tab is processed in sequential order, from lowest numbered tab to highest numbered tab. So if a muscle appears on more than one multiparm tab, then the property setting values on the highest numbered tab takes priority and either multiply (when set to Relative) or override (when set to Absolute) the settings from lower numbered tabs.

See Working with Muscle Property Assignments for more information.

Determines which muscle(s) to assign the current Property Assignment multiparm’s settings to. This parameter only accepts single muscles or lists of muscles formatted in the @muscle_id grouping syntax. For example, @muscle_id=L_biceps, @muscle_id=L_biceps,L_triceps, or @muscle_id=L_biceps @muscle_id=L_triceps @muscle_id=L_deltoid. This parameter does not accept regular geometry groups.

You can specify the group selections for your Group parameter in the following ways:

• In the viewport state, press A, select the muscle(s) you want to add to the group, and then press Enter. A new Property Assignment multiparm is created and the muscle(s) you selected are added to its Group.

• In the Parameter Editor, click the arrow icon next to the Group parameter, select the muscle(s) you want to add to the group from the viewport state, and then press Enter. The muscle(s) you selected are added to the Group.

• In the Parameter Editor, manually type the names (muscle_ids) of the muscles you want to add to the group in the Group field.

This parameter allows you to enter a desctiptive string of text to help you name or identify the properties configured on this multiparm tab.

Turn off to bypass this multi parameter instance without having to delete it.

Determines how strong the constraint is when increasing the distance between the muscle ends and their bones relative to the rest distance, and how much the muscle ends are allowed to move away from the bones. Also determines how rigidly the muscle ends follow the bones' animation.

See the Stiffness parameter description.

This parameter is only available when the Absolute/Relative selector is set to Relative.

Reduces the constraint’s energy from iteration to iteration and determines how much energy is lost trying to maintain the attachment. A high damping value creates a sluggish connection. It does not weaken the attachment however, it just makes the attachment not respond as quickly. For example, it makes the attachment appear more syrupy and the muscle appears to swim towards the bones rather than follow them directly. A low damping value may cause oscillations and jitteriness in your muscle.

See the Relative Damping parameter description.

This parameter is only available when the Absolute/Relative selector is set to Relative.

Determines how far to search for what to attach the muscle ends to. Typically the heat mapped areas of the muscle will attach to nearby bones. The constraint will look within this distance of attachment and will try to find bones within that threshold. If it finds bones, then that is what it will attach the muscle ends to. If it does not find any bones within that threshold, it will keep the muscle ends unconnected.

See the Distance Threshold parameter description.

This parameter is only available when the Absolute/Relative selector is set to Relative.

The rest length of the distance constraints will be the original distance between the muscle ends and their bones. This scale increases or decreases the resting distance during the simulation.

See the Rest Length Scale parameter description.

This parameter is only available when the Absolute/Relative selector is set to Relative.

Similar to the radius controls that exist for the muscle’s tendons, but this applies to the muscle end constraints and their heat map visualizations in the viewport state. These Radius parameter values are used by the muscle ends constraint to calculate the distances from the muscle ends. It looks at what it guesses is the axis of a muscle, and it then takes a distance along that axis. This affects how much the muscle ends constraint kicks in for a muscle.

Adjusts the end mask on the other end of the muscle to Radius 1.