Joint Attribute Types
Each joint in a figure’s bone structure has some or all of the following attributes. The attributes available for each joint depend on the currently selected joint. You can think of the Joint Editor palette as working with body parts or bones, since the end result is the same. For the sake of discussion, it is appropriate to think of the Joint Editor palette as acting on body parts when in the Pose room and bones within the Setup room.
This section explains how to adjust each available joint parameter. Note that not all parameters will be applicable to every joint. Only those parameters applicable to the selected joint will appear in the joint editor.
Center
The Center attribute sets the center of rotation for the selected bone. It is available for all bones, body parts, and props.
Hold your arm out with the palm up, bend it at the elbow, and notice that the center of the rotation is about halfway between your inner and outer elbow. Notice how your skin contracts above the center of rotation and expands beneath it. Imagine if the center of rotation was in a different location and how that would affect the appearance of your arm as you bend it. Move some other joints and imagine the changes that might occur if you shifted those centers. The Center attribute controls this aspect of joint motion.
Center attribute and settings.
The following options are available when adjusting the Center joint parameter:
- Center Point: The Center Point attribute defines the XYZ position of the joint (center of the body part). 0,0,0 is located in the center of the bone structure on the floor. Click the Key icon to create animated centers, as described in .
- End Point: The End Point attribute is discussed in End Points, which follows.
- Orientation: The Orientation attribute defines the XYZ rotation of the joint and its axis. Click and drag the dials to set a value. Pressing and holding [OPT]/[ALT] while clicking a dial resets its value to 0. Click the Key icon to create animated orientations as described in Manually Adjusting Animated Centers and Orientations.
- Align: Clicking the Align button aligns the joint with its underlying body part or group, and will automatically adjust the values in the Orientation fields (above). This option can be useful once you have created groups and attached the bones to the geometry. Prior to that point in the process, however, there is nothing to align the joint to.
- Joint Order: See Setting Joint Orders.
- Zero Figure: See Parts of the Joint Editor.
End Points
If a joint has a single child joint, the endpoint will always be the origin of the child. If there are multiple children (as in a hand) the endpoint can be set manually. This feature is used for some of the interaction tools, such as the Rotate tool for orientation from the origin. If there is no child joint (as with the head, typically) the endpoint is also editable.
End Point attributes.
Twist
The Twist attribute changes the location of the twist deformer for the selected bone.
There is no Twist attribute for the hip bone or its equivalent, since the hip is the parent for the entire figure and twisting the hip twists the entire figure in unison.
When IK is enabled, child bones rotate when the parent is twisted. Twisting the hip normally moves the entire body since the hip is usually the parent for the entire figure, meaning that the hip does not have this parameter.
Hold your arm out with the palm down, and twist it so your palm is facing up. Notice how most of your arm does not change, except for a region in your upper arm where the skin and muscles twist as you move. Imagine if the twisting began and/or ended in a different location. The Twist attribute controls this aspect of joint motion.
By default, the Twist axis runs lengthwise down the center of each body part. For example, the arm twist axis is X, while legs twist along the Y axis. When this parameter is selected, a line with two handles appears on the figure. The red handle represents the starting point of the twist transformation area, and the green handle represents the end. Dragging these handles increases or decreases the Twist area.
Twist attribute and indicators.
The Twist parameter has the following settings and options:
- Display Options: See Parts of the Joint Editor .
- Falloff Zones: See Creating and Using Falloff Zones.
- Twist Start and Twist End: Define the beginning and ending points of a bone’s twist area. Enter your desired values in the appropriate boxes, or drag the red handle of the indicator to adjust the Start value, and the green handle of the indicator to adjust the End value.
You can make twist areas larger than the selected bone, which can make a twisting motion appear more natural. In many cases, the bone’s parent should be included in the twist zone.
You can use the Editing tools to adjust the Twist parameter. This parameter exists in three dimensions, meaning you can rotate the figure to see the joint from any angle. You may, however, want to leave the figure in its default position and use the orthographic cameras (Top, Bottom, Left, Right, Front, Back) to constrain movement to two axes, possibly avoiding much confusion.
- Joint Order: See Setting Joint Orders.
- Zero Figure: See Parts of the Joint Editor.
Side-Side, Bend, Front-Back, and Up-Down
The joint settings for Side-Side, Bend, Front-Back, and Up-Down are very similar. The main difference between them is the axis on which they rotate:
- The Bend attribute controls the angles of the Bend transformers, and defines how bulges are created. To illustrate this, bend and flex various joints (such as your elbow or knee). You’ll notice limits of your flexibility, and how the skin and muscles bulge as you move. The Bend attribute lets you control how this occurs in your figure.
- The Side-Side, Front-Back, and Up-Down attributes control the angles of their respective transformers and also define how bulges are created. These attributes are suited for omnidirectional joints such as your wrists, shoulders, hips, ankles, etc. The various parameters are shown in the following table.
| Attribute | Body Part(s) |
| Bend | All but Hip, Collars, and Shoulders |
| Side-Side | Head, Neck, Chest, Abdomen, Waist, L & R Buttocks, L & R Thigh, L & R Shin, L & R Foot, L & R Toe, Toe1 parts, Toe2 parts, L & R Forearm, L & R Hand, L & R Thumb2, L & R finger parts (other than thumb) |
| Front-Back | L & R Collar, L & R Shoulder |
| Up-Down | L & R Collar, L & R Shoulder |
Bend attribute settings.
The following settings appear in the Joint Editor for Bend, Side-Side, Front-Back, and Up-Down parameters. Each of these three parameters is functionally identical when editing these joint attributes in the Joint Editor palette. The settings in the Joint Editor allow you to change their angles and transformers. Poser can also create bulges that emulate muscle movement.
- Display Options: See Parts of the Joint Editor.
- Falloff Zones: See Creating and Using Falloff Zones.
- Joint Angles: Defines the polygons that are included or excluded from the Bend parameter. You can either use the Inclusion and Exclusion handles to adjust these values visually, or enter values in the Joint Angles fields. The area between the two red handles define the polygons that are excluded and will remain stationery. The area between the green handles defines the polygons that will move completely. The area in between a green handle and a red handle will “deform.” For more information, see Setting Joint Angles.
You can use the Editing tools to adjust the Bend, Side-Side, Front-Back, and Up-Down parameters. These parameters exist in three dimensions, meaning you can rotate the figure to see the joint from any angle. You may, however, want to leave the figure in its default position and use the orthographic cameras (Top, Bottom, Left, Right, Front, Back) to constrain movement to two axes, possibly avoiding much confusion.
- Bulge Settings: See Editing Bulge Settings.
- Joint Order: See Setting Joint Orders.
- Zero Figure: See Parts of the Joint Editor.
Scaling
Each body part has parameters allowing you to scale the parent and child body parts. These settings are similar to the Twist parameters and follow the Twist axis of the child or parent body part. For example, Ryan’s Right Collar body part has scaling controls for the chest (parent) along the Y axis and the Right Shoulder (child) along the X axis.
The High End/Start and Low Start/End parameters define a blending area. For example, when scaling the head, you may also want to scale the top of the neck to achieve a smooth fit. When setting these parameters, only one setting (high or low) is relevant. The unused parameter pair gets automatically set to some unrealistic number (such as 99,000 or 100,000), thus indicating that it is not relevant to the area you’re working on. Do not edit these out-of-limit settings.
Each blending zone’s end is represented in red, with its beginning in green. Effects can be either uniform or can use spherical falloff zones, discussed below.
Scaling attributes.