The Joint SOP will aid in the creation of circle-based skeletons by creating a series of circles between each pair of input circles. This SOP requires at least a pair of circles in order to work correctly.
/group - If there are input groups, specifying a group name in this field causes the SOP to act only upon the group specified. Accepts patterns, as described in Pattern Matching.
/divs - Allows you to specify the number of circles between each pair of input circles.
Preserve First Input
/preserve1 - Preserves the first input circle being fed into the SOP.
Preserve Last Input
/preserve2 - Preserves the last input circle.
/orient - This helps to create a joint that blends between the input circles without flattening or curving outwards. In order to do this, there may be a reversal of the normal of each input circle. For example, if the normals of the two input circles are facing away from each other, the joint created (if this option was not enabled) would appear to connect the circles the long way around. This option would reorient the joint such that the shorter distance is used to create the joint.
/smoothpath - If not on, the joint circles are blended linearly. Otherwise, they are placed along a cubic piece-wise Bzier curve between the circle centres. This is useful when the input contains more than two circles and the joints must be continuous to each other. If this option isn't enabled, the interpolation may be sharper than desired.
/smoothtwist - Each joint circle is rotated slightly such that its X and Y axis align as it approaches an input circle. This toggle causes the adjustments to be an incremental, or piece-wise, Bzier function. Again this is useful for multi-circle inputs.
Align Major Axes
/majoraxes - If enabled, this option aligns the first circle's largest axis to the last circle's largest axis. If disabled, the first and last circles' x axes are aligned. This option can help minimize the twist in the joint ellipses between bones.
/mintwist - If on, the rotations of the added circles are calculated such that they never rotate further than one half turn in either direction. This leads to a visually continuous layout suitable for creating a skeleton, but will cause problems if the circles are later skinned since the beginnings of each circle may no longer be continuously aligned.
Left / Right Scale
/lrscale - These parameters control the shape of the smooth path, varying the shape of the implied curve from the left or right. If the Orient Circles option is on, the sign of the scale has no effect. For a discussion of the relative terms right and left, see Align SOP.
Left / Right Offset
/lroffset - These parameters allow you to override the distance between circles, thereby affecting the shape of the joint.