A Dream of Electric
Sheep - By Phil Baines
As this was
to be a Proof of Principle exercise,
there were a lot of short cuts in order to speed the process up and this was
the first shortcut, as it is a free mesh I downloaded from the web, thanks to
azly. It is only
for personal use so will be replaced when the final version is created, also,
it had several thousand polys which I reduced to 2000, but that is still too
high for this kind of model.
With the
mesh in side view the bones are added to the model to prepare it for animation.
I used a picture of a sheep skeleton I found on the web as a guide in placing
the bones.
Putting the
model into see through mode, bones were quickly added to each limb, the spine,
neck and head. Again, for speed, no attempt has been made to make it very tidy.
Also, as the animations would also be just trial ones, no IK chains were added,
as the bone placements were to be added by hand.
Note, that
whilst it is common practice to re-name bones, root/neck/hip etc, to assist the animation process, this is not
possible in TS2014. They can be re-named but they must be prefixed by bone_. So, "bone_root" is
possible but not just "root".
If you wish
to learn about bone placement there are lots of guides on Youtube.
With the
bones in place the model could be skinned. Skinning is a long and tedious
process to get right so I didn't try too hard, given the temporary nature of
this particular model. So, apologies in advance for some of the images that
follow!
Looking at
the blueprints for existing Platform Characters there are three different
elements. Firstly an AnimProceduralSceneryBlueprint which puts the animated
model into the game. then the PlatformCharactersBlueprint, which collects all
the characters together and finally, the PlatformSectionBlueprint, which is the
loft the characters are generated on.
So the first
requirement was to create the AnimProceduralSceneryBlueprint. The existing
Platform Characters appear to have three different animations, walk, wait and
shuffle, and these seem to be hard coded so, having prepared my sheep model, I
now needed three animations!
I decided to
make the walk animation first and to help me do it I turned to the father of
animation, Eadward Muybridge.
Edward James
Muggeridge was born 1830 in England. At age twenty, he immigrated to America,
first to New York, and then in 1855, to San Francisco, where he acquired an
interest in photography. At this time, he changed his surname to Muybridge.
Under the
pseudonym "Helios," he set out to record the scenery of the west with
his mobile darkroom. He produced a wide array of panoramic landscape
photographs, most famously of Yosemite Valley, and travelled to Alaska to photograph
the Tlingit people.
As Muybridge's reputation as a photographer grew in
the late 1800s, former California Governor Leland Stanford contacted him to
help settle a bet. Speculation raged for years over whether all four hooves of
a running horse left the ground. Stanford believed they did, but the motion was
too fast for human eyes to detect. In 1872, Muybridge began experimenting with
an array of 12 cameras photographing a galloping horse in a sequence of shots.
His initial efforts seemed to prove that Stanford was right, but he didn’t have
the process perfected.
Between 1878
and 1884, Muybridge perfected his method of horses in motion, proving that they
do have all four hooves off the ground during their running stride.
Muybridge
worked at the University of Pennsylvania between 1883 and 1886, producing
thousands of photographs of humans and animals in motion. During the remaining
years of his life, he published several books featuring his motion photographs
and toured Europe and North America, presenting his photographic methods using
a projection device he'd developed called the Zoopraxiscope.
Many
examples of his work are available on the web in picture format and as animated
gif. Unfortunately, he didn't do any sheep but there are animated gif of a
walking pig and I thought its gait was sufficiently close to what I needed for
the sheep walk. Just needed to get the pictures into my modelling software.
OK, here is
the geek bit! Please note, most of these operations do not seem to like
drag-and-drop, so if you want to give this a try, please avoid it.
Save the
animated gif to desk top then open it in photoshop using File\Import\Video
Frames to Layers, and you will see in your layer palette all the layers that
make up the gif animation. Then use Files\Scripts\Export Layers to files, give
them a suitable prefix, e.g. pig and you will have a full set of images to work
with.
There are
two options at this point. Create the same number of planes in your 3d
modelling software as there are animation frames, then create a
Multi\Sub_Object material with each frame as a new sub-object in your material
then apply it to the planes. The planes should then be aligned with each other,
behind the model, where they are hidden or exposed sequentially during the
animation process.
A more
elegant solution is to load the collection of layer images into After Effects
and convert it into a movie. If you haven't got After Effects, it can be
downloaded for a free trial.
Use
File\Import\File and select the first file in your collection of images, tick
the box in the lower right corner for sequence then Import. This should load
all of your images into AE. From the toolbar select Composition\Add to render
queue then click the Render button on the right. This will create an .avi file
of your images. In your modelling software create a single plane then texture
it using the .avi file as a material. This does two things, it add the images
to the plane and creates an animation timeline with a key frame for each image.
Align the plane with your model and you are ready to go.
If you want
to see this operation at work have a look at Dave Saxon's Youtube video here which will demonstrate it better than I can
explain it.
With the
video in place the bones could be animated, frame by frame, with the following
result.
I quickly
made two further animations for the wait and shuffle cycles and added them to
the blueprint. For the wait cycle the sheep just turns its head to one side,
and for the shuffle ir bends to eat the grass.
Next the
PlatformCharactersBlueprint. This blueprint lists all the characters that will
appear on the platform and, as I only had one, was fairly simple to set up.
Other factors of this blueprint decide the population density of the characters
and when they will appear. If you are familiar with placing Platforms as
scenery, these are the adjustable items that appear in the right-hand fly-out
of the editor.
Finally,
there is the PlatformSectionBlueprint. This basically combines a platform loft
with the platform characters to give the finished product. As I wanted to place
the finished item anywhere on the route, the obvious choice was to have an
invisible platform, so the existing terrain would show through. This was easy
to achieve as I regularly use invisible lofts for viaducts, so I already had
the necessary assets. Other items, such as entry point spacing and waiting
point offset, are specified in this blueprint. Haven't a clue how these work so
just copied some values from an existing people platform.
Finally,
ready to place in game and ......nothing!
Took me
nearly a week to work out the problem. Apparently these procedural platforms
don't like being near the edge of terrain tiles. Moved the platform away from
the edge and, at last, a result.
The
following video shows the Sheep Platform Loft in operation. I apologise once
more for the lousy skinning and weird animation.
I hope you
agree I have achieved the Proof of Principle I set out to get, now the hard
work starts, creating a new model with proper skinning and believable
animation, plus the development of a herd of cows as well!
More Soon............................
