Bats in Flight: the Anatomy, Aerodynamics, and Flight Morphology of Bats
a master's research project
Bats, an often misunderstood and feared animal, are actually hugely beneficial to us and keep our environments healthy and running. Unfortunately, many species are currently threatened or endangered, so promotion and support of bat conservation efforts are more important than ever. One of the many interesting and unique aspects about bats — the fact that they are the only flying mammals with many unique flight adaptations — is often not an accessible topic for the general audience; usually the information can be found only in dense research papers with complex graphs and charts.
The goal of this project was to create a three to five minute animation on bat flight which will convey the basic information needed to understand bat flight (anatomy, aerodynamics, morphology, etc.) in an engaging and explicit way so that the general public can understand these complex concepts. This animation will further educate the public on bats in hopes of decreasing negative perceptions and myth beliefs. With an increase in knowledge, positive perceptions, and interest, hopefully the general public interest in bat conservation will also increase.
Dr. Burton Lim (content supervisor)
Assistant Curator of Mammalogy in the Department of Natural History, Royal Ontario Museum
Dave Mazierski (primary BMC supervisor)
Associate ProfessorBiomedical Communications/Biology, University of Toronto
Marc Dryer (secondary BMC supervisor)
Associate Chair—Undergraduate, Department of Biology/
Associate Professor, Teaching Stream, University of Toronto
(thanks to colleen tang poy for narrating)
Script and narration
ZBRUSH MODELING arm & Hand BONES
I started this process by hand modeling the bones of the little brown bat, but found that the lack of good references was leading to inaccuracies. I was then given access to a CT scan of a little brown bat, which after bringing into Cinema 4D and deleting everything but the bones I needed, I brought into ZBrush and cleaned, added back detail, and re-positioned from a folded pose into a spread.
ZBRUSH MODELING little brown bat
With the help of the already modeled wing bones and several image references, I made a low detail 3D little brown bat model in Maya. I imported the model into ZBrush, where I sculpted detail and refined the form. The final touch was painting on the appropriate coloring.
After the bones were finished in ZBrush, I imported them into Maya where I applied materials/textures.
The microscopic hairs were made using Maya's nHair creator. Using nHair I could make several hairs randomly across the surface (which was created by importing a Digital Elevation Map and using the soft manipulation tool) that reacted to physics such as gravity and wind. I had some room for artistic license in regards to color and textures, so I went with a high level of sub-surfacing scattering and a velvet like material in warm oranges to stand out against the darker, purple background.
Maya(little brown bat)
spring & summer 2019
Now it was time to get the bat flying! After importing the model, displacement maps, and color maps into Maya from ZBrush, I started to rig the model for movement. This was done by adding the appropriate joints, painting weights, and finally key-framing the flight pattern. Video resources, especially Sharon Swartz's research website , were used to accomplish animating the flight movement, alongside feedback from Dr. Lim.
The next challenge was modeling the membranes of the wings. It was decided that Maya's nCloth simulation would be the best way to produce the highly flexible wing membranes that help make bat flight so unique. nCloth isn't perfect, though, and after producing the nCloths and constraining them to the bat model, there were issues with clipping and breakage of constraints during movement. I had originally modeled the wing membranes fully stretched out, but found the nCloth would clip through itself when folded in too far; this was solved by remaking the membranes with the bat in a folded position. After playing around with settings I was able to find a good compromise between what would be too stiff and what would be the truest level of flexibility for the membranes.
Original flight pattern and wing membrane nCloth settings
Finalized flight pattern and wing membrane nCloth settings
The last addition to the bat model was the body fur. This was created with xGen due to it's grooming capabilities. While xGen is not a dynamic simulation like nHairs or nCloth, there was a built in wind that I applied to have the hairs move.
After these were all done, I was able to build scenes with backdrops, lighting, 3D graphic arrows, wind tunnels, etc.
photoshop & hand drawn 2D animation
I knew it was important to include the diversity of bat species in my animation. Modeling and rigging 8-9 different bats was not realistic for the production timeframe, and I had wanted to build on my 2D animation skills that I had already been working on during fall semester. Why hand drawn animation? Outside of being a skill I was interested in learning, I thought the aesthetic and feel of movement that comes with hand drawn vs. vector animation was more appropriate for the fluidity of bat flight, along with providing a nice contrast against the more sleek and clean-cut aesthetics of the 3D scenes.
All the animations were drawn in photoshop, using the frame animation timeline and a multitude of layers. The style is a faux-rotoscope, where I looked closely at each frame or every 2 or 3 frames of bat flight videos as reference.
I also drew a few bat portraits in photoshop for the map scene.
After all 3D and 2D animation renders had been made, I brought them together in After Effects. Here I matched the animations with the final recorded narration and added in sound design, final transitions, labels, text, 2D vector graphics, and other video manipulation effects (such as time remapping and motion blur). I also added and edited the live footage I filmed at the Royal Ontario Museum's Bat Cave.