New Errata coming soon and understanding corrective pose space deformations.

We got an email from a very dedicated reader that wrote up an excellent, detailed errata doc where he not only worked through problems he found in the book by figuring out the answer, he then wrote them all up and sent it to us!

We are looking over the errata as time permits and will post it once we check it out.

Thanks again to our readers for being true technical artists and finding solutions to problems presented in the book, even when they were not supposed to be problems:)

*A few notes about some of the information in the book on corrective shapes or Pose Space Deformations (PSD) rigging.
It has been brought up quite a bit over the years that the pose spaced deformations in the book don't work when you move the skeleton hiearchy above the blendshape.

This is correct, with out several extra tools /plugins creating a true PSD system with default Maya that works on a rigged character is not possible.  The book covers a workflow for creating PSD fixes that can be blended on and off over the course of a final animation, often times called shot sculpting, this workflow allows fixes for final animation that is causing deformation problems, to be corrected in a "fix it in post" system on the skeleton rig.

A point cache/geometry cache approach to this would be to cache out the mesh and in Maya Trax and Artisan , paint sculpt fix clips that can be adjusted and blended over top of the animation in a non-destructive way to fix difficult deformation issues.


Real PSD / Corrective Shape tools-

Thanks to Michael Comet and his plugins you can get this for free in Maya, with some work.
http://www.comet-cartoons.com/maya.html

you can get the latest recomplile  for Maya 2011 from DJX http://www.djx.com.au/blog/downloads/  
And find a detailed how-to  on using the Comet tools here http://www.tokeru.com/t/bin/view/Maya/MayaPoseDeformer

Another popular tool is http://www.b-ling.com/ Corrective shape tool though only for older Maya versions.

And there are several other UV driver tricks that work well for faking a true PSD solution in Maya but all of them are lacking in some way or another.


Some new tools are on the horizon that will allow for true PSD solutions on a rigged character that can also be used for post clean up as shown in this clip from JoeAlter Inc. and his Lbrush tool.





And for most people looking to set this kind of thing up, it is to deal with muscles and other tricky issues, you will want to go down the rabbit hole and check out the amazing amount of complied reference on Muscles and rigging here
http://chrisevans3d.com/reference.htm

That is it for now, Hope this helps give you all some deeper understanding of Pose Spaced Deformations

Errata: new update for the two handed prop tutorial

In an effort to fully support our readers I am posting this update on the main blog and the main google errta doc has been updated as well.


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Chapter 8: page 164 step 7:
change

Select the “staffCtrl” node and group it with Ctrl+g.
To
Select the “staff_Ctrl” node and group it with Ctrl+g.

Chapter 8: page 165 step 12:
change

Group this node and rename it “staff_r_hand_offset_attach.”
To
Group this node and rename it “staff_r_hand_attach.”

(this change is to the name only. so that step 13 makes sense.)
Your really doing the same thing as you did in the knife tutorial but
adding an extra target and switch for the left hand to
be stuck on to the spear...the concepts are the same)

*also note that once the rig is done you can clean up the visual
hierarchy like you did at the end of the knife rig.

Errata: new update for the spine rig- chapter 7

First a huge thanks to reader "J" for find this problem and letting us know.

The errata doc is current and I am posting the changes here as just the update.
I had changed the way I rigged the spine for the example file and simply forgot to update and clean up this part of the chapter.

Here is the fix to match the down loadable final character.

Chapter 7: page 134, paragraph 4, step 2:
change “”Auto Parent Curve off and Number of spans set to 2.”” to “Auto Parent Curve off and Number of spans set to 3.”

Chapter 7: page 135,

step 5:
change- ignore/delete

step 6:
change ”Name the curve “ctrl_chest” and zero out its translation. Then parent the control curve shape node under the “ctrl_chest.

To ”Rename the joint "ctrl_spineChest" to "ctrl_chest". Then parent the control curve shape node under the "ctrl_chest".

step 8-
change “orient-constrain “spineChest” to “ctrl_chest.” to “orient-constrain "bn_spineChest" to "ctrl_chest"

Chapter 7: page 136,

Step 15. - Because our FK spine controls are the parent of the upper "ctrl_chest" you are always in a mixed state of IK and FK, when the ctrl is zero, you can FK rotate the spine joints and the "ctrl_chest" and the rig is in FK mode. but at any taime you can choose to translate the "ctrl_chest" and are now in IK mode for the back, if you want pure FK gain you can zero the "ctrl_chest" and your blended back to pure fk.

Step -16 ignore/delete