By: John Cordeiro

click any image to enlarge

 

psd_Start

Start Scene

The poseDeformer plugin is an amazing tool that allows character riggers the ability to quickly generate corrective shapes for poses in a similar method to using blendShapes.

Start Scene:
As an example I start by creating a polyCylinder with the following settings:
radius = 0.5, segments = 8 and segments hight = 10, along with a 5 joint chain, the cylinder is smooth bind skinned to the joint chain.

To follow along with this tutorial download the StartScene file.

Step 1:
Launch poseDeformerUI

Step 1

Step 1

Select the cylinder (skinned object) and add it to the UI by clicking the <<< symbol at the end of the field choose skin geo.

Rename the poseDeformer in the field under the geo name, this will be the name of the deformer.
I suggest using the limb name, example: L_Arm_PoseDeformer

Step 2:
Select joint4 and rotate 90 degrees on the Z axis, the geometry should collapse where it bends.

Step 2

Step 2

 

 

 

Step 3:
Click prep for sculpting, the geometry will change to the color selected in the UI. This will create a copy of the skinned geometry with no history and hides the original skin

 

Step 3 - 4

Step 3 – 4

 

Step 4:
Use any tool you please to adjust the geometry at this pose, the sculpt tool, move vertices, lattice deformer or any other means. You can even export the geometry to a separate sculpting program and adjust the geo, see Using a sculpting program below.

 

 

Step 5:
Select only the influence object used to create this pose, in this case joint4.

Step 5 and 6

Step 5 and 6

Step 6:
In the field Parent poseReaders to: set the name of the parent object to hold the poseReader node, I select the joint prior to the one i’m rotating in this case joint3.

Next type a name of the pose in the Pose Name field, I used RotateZ90 as the pose name.

Set Options:
blendMode = RBF-LUFactorize
deformSpace = joint-space
avgPoseSepRBF = 60

Step 7:
Click Create / Edit Pose and Readers, this will generate the poseReader node and hides the sculpted geometry.

Step 7

Step 7

Now the poseReader is pointing in the Y axis, if you rigged your character like the example with X running down the joint chain, change the read axis in

Read Axis

Read Axis

the poseReader attributes to X-Axis. Now the cone is pointed in the proper direction.

 

 

 

 

Problems:
You may notice a pulsating in the skin as you move the joint back between 0 and 90 degrees, this is from the cone size not being big enough to influence the skin throughout the rotation.
The settings for maxAngle are 0 – 90

Set Max Angle

Set Max Angle

To fix the problem and smooth out the deformation:
Select the poseReader in the outliner, it will be parented under joint3, the joint we selected in step 6.
Set the max Angle to 90 this will flatten out the cone to a line, consider it like widening the cone of a spot light.

Additional Poses:
I create a additional poseReader at 130 degrees and add some bulging to the geo as it bends to the 130 mark on Z.

With the poseDeformer still open if you closed it after step 7 see Tip and Tricks below.
Starting at Step 2, this time rotate joint4 to 130 degrees on the Z axis.
Click prep for sculpting and again use whatever means necessary to fix the geo in the current pose.
Select only the influence object used to create this pose, in this case joint4.

Additional Pose rotate Z 130

Additional Pose rotate Z 130

In the field Parent poseReaders to: set the name of the parent object to hold the poseReader node, joint3.

 

Next type a name of the pose in the Pose Name field, I used RotateZ130 as the name for this pose.
Click Create / Edit Pose and Readers

You will now have 2 poseReader nodes affecting the skin.

Additional Pose Step 7

Additional Pose Step 7

Again you may notice a weird movement in the skin as you move the joint back between 90 and 130 degrees, this is from the cone size being to big and affecting the pose at 90 degrees too early.
To fix the problem and smooth out the deformation, simply rotate joint4 back to 90 and select the poseReader node for the RotateZ130 node.
Set its max Angle to 30 or slightly lower.

Tips and Tricks:
You can also adjust the average pose separation RBF, its found in the output of the poseReader node. A setting between 50 and 70 work well for most cases.
The max Angle and the RBF settings are the main two values that the math is comprised of, too much max angle and the sculpt pose will affect the natural pose.

Edit poseReader

Edit poseReader

If you close the poseDeformer UI and want to add more poses simply restart the poseDeformerUI and select the skinned geo and click <<< next to the field.
This will read in the poseReaders that exist in that deformerSpace.

Using a sculpting program:
To export the geometry to another program such as Zbrush or Mudbox, select the sculpt ready geo and export selected as OBJ, import into sculpting program and make necessary changes to the affected area, export and import back into your scene and hook up the new geo as a blendShape on the sculpt ready geo. Now simply continue with steps.

 

I have not tried the plugin goZ for this but it should work without having to apply the blendShape step, the same with send to Mudbox from within maya’s file menu.

Happy Rigging!!!

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