READMEFIRST for Daz-friendly, hip-corrected release
v1.0, last update July 28, 2010 by B. Hahne
Web site: www.cgspeed.com (see the motion-capture section)
This READMEFIRST file accompanies the primary Daz-friendly BVH
conversion release of the Carnegie-Mellon University (CMU) Graphics
Lab Motion Capture Database. See "Where to find stuff" at the bottom
of this file for where to get the BVH conversion and/or the original
CMU dataset.
The original CMU motion capture database isn't in BVH format - it's
in ASF/AMC format. This BVH conversion release was created by Bruce
Hahne, a hobbyist animator, in the interest of making the data more
available and easily usable by other animators. I presently (2010)
maintain the web site www.cgspeed.com, where this BVH conversion
release is available within the motion capture section.
This is the third major conversion in an occasional series of
conversions of the CMU BVH data into various forms designed to be easy
for hobbyists to use. The history so far is:
2008: First Motionbuilder-friendly release
2009: 3dStudio Max biped-friendly release
June 2010: Second (slightly improved) Motionbuilder-friendly release
July 2010: Daz-character-friendly release
This release is a set of BVH files designed to work seamlessly with
the 3rd-generation (gen3) and 4th-generation (gen4) prerigged
characters from Daz (www.daz3d.com). These characters include, for
example:
Aiko3 Victoria3 David3 Michael3 SP3
Aiko4 Victoria4 SP4
A video tutorial on how to use these BVH files with Daz Studio is
available at cgspeed.com.
I've spot-tested the BVH files from this Daz-friendly conversion in
Daz Studio 3. In theory they should also work with the Daz gen3 and
gen4 characters within any release of Poser or Carrara, however as of
July 2010 I haven't tested with either of these packages.
This Daz-friendly release is derived from the 2010 (second)
Motionbuilder-friendly release using the following workflow:
1. I ran the Motionbuilder-friendly BVH files through a retargeting
script in Motionbuilder, to retarget them onto the Aiko3 skeleton.
2. I ran the resulting Aiko3-compatible BVH files through a
hip-correction script to work around a sporadic Motionbuilder BVH
export bug. Motionbuilder 2009 occasionally saves bogus hip rotation
values for some (but not all) frames of an animation when exporting in
BVH format. (Motionbuilder 2011, presently in beta as of this writing,
is much worse - it doesn't even export proper BVH files at all). The
workaround for this bug was to replace all hip rotation values with
the original rotation values from the motionbuilder-friendly,
pre-retargeting BVH files.
A version of the Daz-friendly BVH files WITHOUT the hip correction
algorithm is also available at cgspeed.com, however that isn't what
you've downloaded with this particular release.
ADVANTAGES AND FEATURES OF THIS RELEASE:
- The BVH files are entirely retargeted to the Daz gen3 and gen4
skeletons, and should import seamlessly onto these Daz characters
with no need to mess around with joint renaming or post-import
rotation corrections. If you've struggled in the past to use BVH
files to animate Daz characters, you should give this dataset a try
or watch the training video - it's very fast to use this BVH release
with the Daz characters.
- Unlike other attempts at releasing Poser-friendly or Daz-friendly
conversions of this dataset, this conversion has run the files
through an actual retargeting algorithm in Motionbuilder. Other
attempts at Poser-friendly releases that I've seen contain massive
joint-snarl and rotation-snarl problems. This release should avoid
most of these problems, since Motionbuilder did the heavy lifting.
- Index files: As always, the release includes consolidated indices
that list the motion filenames and their descriptions. Both
spreadsheet and word processor friendly index files are available.
- This Daz-friendly release is based on the latest
Motionbuilder-friendly BVH release, which provides better leg and
neck rotation corrections than the 2008 release. The result is that
when you animate Daz characters using this Daz-friendly release, you
typically don't get the problem of the character's head being bent
down at a severe angle.
- Preserves the 120fps of the original CMU dataset - you get every
frame from the original capture (both the good and bad data...), not
a downsampled 30fps version.
CAVEATS:
- The original CMU motion capture data was recorded several years ago
in a non-profit academic environment by people who weren't necessary
experts at operating the motion capture system. The data was never
cleaned and contains a wide variety of joint-flipping problems
characteristic of "dirty" motion capture data, when the Vicon
joint-tracking software makes an incorrect guess about how a joint
has actually rotated. All releases of the CMU data preserve these
joint-flip problems in all of their (ugly) glory. Typically the only
way to get rid of them is manually clean the data, which is of
course a time-consuming and tedious process. Some of the capture
data is quite good, but other captures, particularly earlier in the
numeric series of directories, have a lot of joint-flip problems.
- Because MotionBuilder 2009 has a hip rotation BVH export bug, I've
run this release of the Daz-friendly data through a hip-correction
script that, for the most part, does an excellent job of undoing
Motionbuilder's bug. However, occasionally this script introduces
foot-slip / floor-contact problems - see for example animation
directory 144, file 144_05.bvh. If you discover an animation in
this release that you don't like due to foot-slip problems, you
might want to take a look at the "Daz-friendly, hip-uncorrected" BVH
release, since I'm also releasing the full set of Daz-friendly BVH
files PRIOR to application of the hip-correction algorithm. The
"hip-uncorrected" release is at cgspeed.com, as usual.
- This release provides 120fps BVH data, as do all of the BVH releases
I've done so far. Generally you'll want to set your animation
software to 30fps (for NTSC), 25fps (for PAL), or 24fps (for film)
after you've done the BVH import, since these fps rates are what
most video-editing software will expect.
- These BVH files are not designed to work with non-Daz characters
such as E-frontier / SmithMicro characters, Miki2, RuntimeDNA
characters, etc. I also don't know if they'll work cleanly with
lesser-known Daz figures such as The Freak, The Girl, etc.
- Since it's impossible to test 2600 different BVH files on a dozen
different Daz characters within 3 different applications (Daz
Studio, Carrara, Poser), there are plenty of combinations that might
give you "interesting" or undesired results. However, work so far
within Daz Studio has given positive results.
- Blender users: I have yet to see a successful import of a Daz
character into Blender, and Blender uses a "z axis up" world
coordinate system that makes life even more difficult miserable for
converting a variety of data, so please don't hold your breath
hoping that this Daz-friendly release will be usable in Blender any
time soon.
INDEX/INFORMATION FILES:
Each .zip file in this BVH conversion release should include a copy of
this READMEFIRST.txt file, plus four variations of the same motion
index information:
- cmu-mocap-index-spreadsheet.ods: Open Document / OpenOffice
spreadsheet format
- cmu-mocap-index-spreadsheet.xls: Microsoft Excel format
- cmu-mocap-index-txt.txt: A simple text file with the index
information and no commentary.
- cmu-mocap-index-text.rtf: Rich Text Format index information with
some commentary.
USAGE RIGHTS:
CMU places no restrictions on the use of the original dataset, and I
(Bruce) place no additional restrictions on the use of this particular
BVH conversion.
Here's the relevant paragraph from mocap.cs.cmu.edu:
Use this data! This data is free for use in research and commercial
projects worldwide. If you publish results obtained using this data,
we would appreciate it if you would send the citation to your
published paper to jkh+mocap@cs.cmu.edu, and also would add this text
to your acknowledgments section: "The data used in this project was
obtained from mocap.cs.cmu.edu. The database was created with funding
from NSF EIA-0196217."
AFFILIATION: I (Bruce) am not affiliated with and don't speak for
Carnegie-Mellon University, and they don't speak for me. :-)
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CONTACT INFO AND WHERE TO FIND STUFF:
This BVH conversion release: www.cgspeed.com in the motion capture section.
Original CMU database (not BVH): mocap.cs.cmu.edu
AMC2BVH freeware utility: http://vipbase.net/amc2bvh/
MotionBuilder: www.autodesk.com/motionbuilder
BVHacker free BVH editing software: http://davedub.co.uk/bvhacker
BVHacker is designed primarily to create BVH files for SecondLife.
To contact the creator of this BVH conversion release: hahne@io.com
If you like this BVH conversion release, feel free to drop me email
and let me know what you're doing with it.