Sculpting Work

Here are my digital sculpts (Click the images for high-res view). I put a lot more detail into the skin through ZBrush, after Autodesk Mudbox was giving me a lot of trouble with memory handling. Constant crashes and clunky pipelines drove me to ZBrush which has been much more stable. All of the scale detail is from black and white "alphas" sampled from actual crocodylian images. The tail and underbelly came from an alligator, and the sides, neck and arms came from gharial texture reference. It could be a bit cleaner but ZBrush is giving me a problem with subdividing one more level. It should be enough detail for now, but I'm looking for methods to get that final subdivision level that would make it all around polished. I might be able to achieve it through adjustments to the exported displacement map in Photoshop. Anyway, next is painting the skin and attaching the skin to the muscles (which seems to be relatively straight forward from the tests I did). I got approval on my muscles from Dr. Dodson, other than a few minor tweaks in positioning that I have to do. Mostly the back muscles didn't go quite high enough, so I will adjust that. Hopefully I will be getting some more motion tests out this weekend or early next week if all goes to plan! Very Exciting!



On another note, check out the recent article in the Drexel Triangle that talks about the Drexel Paleo program, as well as mentions a bit about my project, here.

LOTS of Progress!!!

Sorry for the severe lack of updating on all of this...in the meantime, here are a bunch of images to show you where I'm currently at. I started and finished the muscle system...pending approval from the committee, and I just finished the base mesh. That is the mesh below does not have any textures, shaders, or sculpted displacement (scales, fine skin texture etc) just yet. That's the project for the weekend. Hopefully sometime too I'll get around to posting a video of the dynamic squashing and stretching of the muscles in action. Very Exciting...anyway. I'll probably post my UV pelt this weekend....they always make interesting images in and of themselves...

As always, be sure to click the images for the full resolution versions:

Above, you can see the muscles (red) laid over the fossil (blue) and appended bone (green).

Above: Details of the edge flow for the Thoracosaurus model.

Now it's on to combining the skin to the skeleton/muscle....wish me luck!

-Evan B.

First Test Animation of Thoracosaur Rig - IN STEREO!

First Test Animation of Thoracosaur Rig - IN STEREO! from Evan Boucher on Vimeo.

Alright everybody, I know I've been slacking on documenting my progress up here lately, so to make up for it here's another video for now. It's in stereo for a test for another class, so if you have any anaglyph glasses laying around, grab 'em.

Here's a quick breakdown of progress that will soon be documented (and by soon I mean I will probably force myself tomorrow or the next day to buckle down and bang it out).

1. The full Skeleton is built - complete with appended transverse and spinal processes for the eroded vertebrae

2. The working units of the scans apparently were not set to real world units when exporting from Geomagic, so the scene has been resized appropriately.

3. The base rig was built. The creature is now fully poseable and animateable. There are some important issues to note and discuss about the balance between complete scientific accuracy and useability/practicality of the rig interface.

4. Environmental Work - I've been manually stitching a plethora of images I took in the Estero de Tamarindo in Las Baulas National Park, Guanacaste Costa Rica. The images are of mangroves along the estuary. I took some 20-30 photos and stitched them together in photoshop, creating a panorama to be used as an environmental backdrop for the final Animation.


5. I did an early animation test which is embedded above.

6. Muscle development - I have a full shoulder/upper arm rigged with muscles. It's going much quicker than expected and I'm very excited about it.


Stay Tuned for more details/videos/Rig Breakdowns

-Evan.

Finished Skeletal Model!

Thoracosaurus neocesariensis Skeletal Turntable - WIP from Evan Boucher on Vimeo.

Here is a playblast of the Completed skeletal model of Thoracosaurus neocesariensis (Crocodylia: Gavialidae).

The model is color coded - anything that is green is laser scanned fossil data, and the cream color was all hand modeled or sampled from duplicated scans. The green color for the scans is in honor of the green sand (glauconite) of New Jersey where the fossils came from.

The next step - Muscles! 

Soon I will post more on the successes, failures, and intense headaches of the actual modeling process.

Reconstruction / Skull Morphology.

I. Finishing the Assembly

Assembling the final pieces of the skeleton took a bit of time, mostly because of the number of bones there are and how to place all of them. There was also a setback that I didn't notice until using photographs of the Thoracosaurus display case to guide me in placing the bones. It turned out the 11th vertebrae had been skipped in scanning somehow. I had the  10th and the 12th, but not the 11th. I started to freak out a bit, but realized that about a year ago, Mark Petrovich had scanned half of the skeleton with an older, clunkier software.  Luckily these scans are still backed up in multiple places. Mark and I then had to find these bones that were skipped and piece them together in PET (Polygon Editing Tool); which has a tendency to want to crash every time a user saves. I also want to note the importance of labeling and documenting the process of scanning. The students who were in charge of the scanning had a tendency to not adhere to strict naming conventions, which caused much confusion and might have been responsible for how a bone was skipped. I had also noticed some things labeled incorrectly, such as some of the skull bones. The basioccipital from the skull was also labeled as one of the dorsal vertebrae. There were also a few Caudal vertebrae that I noticed were somehow scanned out of order. I was able to sort this out though after using the reference photography. These are all reasons to make sure that whoever is in charge of a digital paleontology like this must have some sort of background and interest in the subject before diving in. This will reduce the number of errors that take place. Not just any digital artist should undertake such a daunting task. I have been trying to correct some of these mistakes by starting to go back into the original data files and renaming files and organizing them correctly. I don't want to confuse anybody who attempts to work with this data down the road after I've graduated from Drexel.

Back to the assembling front, the bones (even though severely reduced in resolution) had a tendency to be very processing intensive in the viewport of Side Effects Software's Houdini. In order to more efficiently place the bones, I set up a "switch" for each bone. This switch allowed me to place the lowest resolution version of the scan, and then move a slider to swap out the low resolution geometry for any of the other resolutions. This let me use much less computing power to place the bones initially, and then swap them for more detail for continued placement finessing as well as rendering. Then, I set up an interactive slider to control all of the switch nodes. This made it very easy to just swap all of the geometry for the entire skeleton at once; to lower or higher resolutions as I needed. This is what brought me to a point where I could go in and start modeling the rest of the bones. Since my comfort zone for modeling lies with Autodesk Maya, I had to then transfer the final pieced and reconstructed skeleton from Houdini to Maya. I simply exported an .FBX file which contained all the geometry. When importing this .FBX into Maya, the geometry came in as a singe giant piece, which would not work for adjusting placement, and rigging the creature down the road. I had to make sure to use the Mesh > Separate option in order to split the geometry back up into the individual objects. This option basically just takes any pieces of geometry that are independent from one another (i.e. the vertices aren't merged) and splits it up into separate objects based on these boundaries. The wonderful thing about once this was done, is the 10K resolution for every bone runs extremely smoothly in Maya. This is because Houdini was referencing external .OBJ files for each and every bone, where as Maya keeps this geometry recorded in the .mb file. Once this was all set up, it was time to start modeling the missing pieces.

II. Modeling the Missing Bones: Part I: The Skull

Knowing it would be the most difficult part to model, I decided to tackle the skull first. The skull is also the place with the most distinguishing features for crocodylians.  The difficulty of this task was compounded by the fact that there is not much literature to be found on Thoracosaurus neocesariensis in particular. Since there is little information to be found strictly on Thoracosaurus I had to base the shape of the skull on the closest relatives I could find in the literature. The main two that I based my recreatd skull off of are Eothoracosaurus mississippiensis (Brochu 2004) and the modern Gavialis gangeticus. So this places it somewhere between a very basal gavialoid  which thoracosaurus is very close to, and modern gharials. One major reason for using Eothoracosaurus is because of how in Brochu's description of the species, he is actually reinterpreting what Kenneth Carpenter described as Thoracosaurus neocesariensis in 1983.  Brochu points out key differences between the osteology of this specimen and Thoracosaurus. His paper also includes a plethora of photographs of Eothoracosaurus complete with scale markers. This allowed me to import these images into Maya and set them up on image planes for me to use as cross sections to model from.  I had a very good top and bottom view of the skull as well as a great top view of the jaw from the type specimen of Eothoracosaurus. Brochu's paper also included a side and back view of a braincase of another Eothoracosaurus specimen.  I have noted and tried to incorporate all the relevent differences noted between the two species.  For the pieces I didn't have reference images from Eothoracosaurus, I tried to use gharial skull photographs. I found some great 360 degree turntables of a gharial skull that was CT scanned. It can be found on the website for the Digital Morphology database at the University of Texas at Austin (www.digimorph.org).  Most of all, even though I modeled off of this great reference imagery, I made sure to to use the contours of the actual skull scans to drive the appropriate shapes in the skull. 

The area of the skull ventral to the braincase (pterygoids, transpaltine, etc) of the skull was very difficult to model since the orthographic photographs do a great job of compressing any sort of depth. This is the one time in my life where I actually see a point to stereoscopic images, and also how they could really help paleontology (check this out). I did the best I could from a number of orthographic photographs as well as posed perspective reconstructions of crocodylians.

When creating the snout, the gharial skull was much longer than the Eothoracosaurus skull, so there was some questioning on how I should tackle this issue. I opted to go with the longer skull, but for a reason. In my research of gavialoid crocodylians, I read that snouts in modern gharial are allometric (Whitaker 2007). Apparently as gharials grow, their snouts become shorter and blunter over time. In the fossils of our Thoracosaurus, in the skull fragments there are very clear sutures that have not yet completely fused together. This lets us know that this individual was not a full grown adult. Combining this fossil data with the analogue of allometry in gharials is what led to my decision of building a longer snout than the one found in the type specimen of Eothoracosaurus described by Brochu. 

The teeth took quite a bit of time to add in. I based the number of teeth on a combination of the relative space between the scanned fossil teeth that are still embedded in a piece of the dentary, the number of tooth sockets found in the Eothoracosaurus orthographic images, and how many of those fit in the extended gharial snout. The alveoli (sockets) took a lot of time to embed in the jaw. I had to use some techniques to kill off edge loops as they radiate out from the relatively dense alveoli to the rest of the snout. It was a lot of brute repeated modeling task-work.

The most puzzling aspect of the skull was definitely the lower jaw. The Eothoracosaurus jaw is much more robust and dorsal-ventrally expanded than the gharial jaw. The gharial is much more streamlined. I started with the overall top view of the jaw which worked fine, but the side view is where the discrepancy showed up. If I went strictly off of the Eothoracosaurus jaw, it would angle down pretty far away from the top of snout, which made it look like the teeth would never be able to clasp together. So I attempted to use the articular surface between the articular and quadrate from the Eothoracosaurus and combine it with a more gharial-esque jaw. If one follows this jaw rostral, there's suddenly a problem with the actual scanned part of the dentary. It has a pretty sharp angled kink in it when viewed from above, so I placed it where it matched along the length of the jaw in the top view. In the side view this makes it appear too tall for the gharial jaw and too short for the Eothoracosaurus jaw. The only way to fit it in seemed to be to have a relatively drastic kink upwards after the scanned portion as the jaw approaches the tip.  





This is when I noticed an area on the inside of the scanned dentary piece. There appears to be a crack conveniently placed at the "kink" mentioned earlier. It looks like there's the possibility that this kink isn't actually osteological. This crack looks as if this kink is a result of finding the best fit for the Paleobond glue to hold the bone together for display purposes. This is something I have noticed in my fossil preparation experience. Highly fragmented bones, when glued together have a tendency to get somewhat warped around a bit. I did an experiment with fixing this "kink," which could not normally be done easily in the physical world. I set up a deforming lattice and just warped it into a position where this crack fused. when removing this kink, the scanned dentary piece fits better if it's further back on the jaw. This then seems to fit very close to the gharial jaw reference, and creates a more gradual thinning of the snout. This is something I need to consult the experts on, but I'm pretty convinced that this is how it should be. I will stop playing with the skull until I get feedback, and move on to the rest of the skeleton. This process has been extremely difficult. It is very different than my previous character modeling experience. With that it's an artistic choice when something looks good enough to move on. With this, it's much slower to try to ensure that every bit is as accurate as can be with the data that we have.
 

Poly Counting

 (For all images below, feel free to click on them to view the full sizes)


I. Poly Counts

This Past week was spent with a lot of time looking at ways to reduce polygon counts of the fossil scans in order to make them useable for animation without crashing every program known to man. The full resolution scans are priceless for the scientific community, but are very impractical in an animation production environment. I was worried I would have to block model every bone to create low resolution versions to use, but luckily, there is a tool inside the scanning software (Geomagic Studio) that allows a user to specify the number of polygons to reduce the geometry to. Based on past characters I have built, I estimated that around 10,000 triangular faces is a good number to use to keep a lot of the detail while reducing the number of faces significantly. The original scans were coming in around 400,000 tris...so reducing to 10,000 is an extremely significant reduction (About 1% of the poly count of the original) but doesn't take away too much of the detail.

  

 

II. SKELETAL RECONSTRUCTION

After I created a series of lower resolution versions of each bone, (10K tris, 5K tris, and 2K tris) I started to put the skeleton together. I used the procedural nature of Side Effects Software's Houdini in order to allow me to quickly position the low resolution versions, and create a switch that automatically swaps out the geometry for higher resolution versions. I will soon be looking into creating some sort of script that allows me to swap the 10K resolution bones to the full resolution bones at render time, so that the computer doesn't ever have to display them in the view port, which crashes the program every time.

 

...and just for kicks, here are some other views of the 10K resolution:

III MISC.

 I've also done some more R&D for muscle systems and for environment development....more on that to come soon. I have gone through the whole pipeline for Maya muscles a couple times to familiarize myself with that, and I have been putting myself through a crash course in Real Flow for water dynamics. Stay tuned for updates on that.

On a side note, in my continued research for croc anatomy, I came across the relatively recent British television series, titled Inside Nature's Giants, where a team of scientists dissect a different large/specialized animal in each episode. One episode happened to be about the Nile Crocodile! This was very informative in not only showing the musculature and other structures underneath, but also putting the anatomy in a physiological and evolutionary context. It was extremely effective and I learned a lot very quickly. I strongly recommend it to anyone who's interested in this stuff. The other episodes were pretty great too (I especially liked the one about the giraffe).

Knee Deep in Literature

So lately I've been delving deeply into the Literature, trying to resolve some of the issues with the missing skeleton parts.  To get my feet wet, I read through the skeletal portion of Robert Chiasson's Laboratory Anatomy of the Alligator. After that it was an in depth looks at some Christopher Brochu Papers, including some about crocodylian phylogeny issues, and some papers about Eothoracosaurus and Eosuchus. Unfortunately I was having trouble finding any papers dedicated to Thoracosaurus neocesariensis in particular. Every lead I had pointed back to a Kenneth Carpenter paper on the species, but I have been having trouble locating a copy. That being said, Brochu describes the same specimen that Carpenter does, and argues that it is in fact not actually Thoracosaurus, and distinguishes it as Eothoracosaurus. In these comparisions I was able to find out some descriptions of Thoracosaurus, which was very helpful.

For what I cannot find on Thoracosaurs neocesariensis I will have to extrapolate from the other "thoracosaurs" (Eothoracosaurus, Thoracosaurus, Thecochompsoides) as well as the modern gavialis.

I then did some reading up on Gharial descriptions and behavior. I found some great information on their hunting behavior in particular, which was very interesting. I am very close to being able to draft up a proposed animatic based on the behavior of these large fish-eating crocodylians. I have also been looking for video documentaries on gharials to watch and study, so I can see some of this described behavior in action. BBC motion gallery is a great reference but only goes so far.

I am now working on a large variety of things. I need to jump head first into the muscle systems. But more importantly I need to figure out the best way to create low resolution "proxy" bones to act as stand-ins for the high resolution scans, so that I can actually rig and animate them. That's the next thing on my list. I may have to hand model some simple proxies, and the scanning software (Geomagic Studio) may be able to do a lot of the heavy lifting for me. Then I'll have to write some sort of script that substitutes the proxies with the full quality at render time... Lots to do lots to do! Stay tuned for more updates. Once I figure out this pipeline, I promise I'll post a rendered image of the full digitized skeleton.

Literature Read this Week:

Brochu, C. A. (2006) Osteology and phylogenetic significance of Eosuchus minor (Marsh, 1870) new combination, a longirostrine crocodylian from the Late Paleocene of North America. Journal of Paleontology 80(1):162-186.

Brochu, C.A. 2004. A new Late Cretaceous gavialoid crocodylian fromeastern North America and the phylogenetic relationships of Thoracosaurs.

Brochu, C. A. 2001. Crocodylian snouts in space and time: phylogenetic approaches toward adaptative radiation. American Zoologist 41:564–585. 

A study of fossil vertebrate types in the Academy of Natural Sciences of Philadelphia: taxonomic, systematic, and historical perspectives Issue 16 of Special Publication Series, Academy of Natural Sciences (Philadelphia, Pa.) By Earle E. Spamer, Edward Daeschler, L. Gay Vostreys-Shapiro. Academy of Natural Sciences, 1995

Thorbjarnarson, John B. 1990. Notes on the Feeding Behavior of the Gharial (Gavialis gangeticus) under Semi-Natural Conditions. Journal of Herpetology 24: 99-100.
 
Whitaker, Romulus. 2007. The Gharial: Going Extinct Again. Iguana 14: 24-33

* The list on the right hand side is what is next in que for the research aspect of the project. If anyone has any suggestions of papers to read, please let me know and I'll incorporate it into my que!

Oh yes, and I appologize for the lack of pictures.