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| The Ongoing Trilobite Reconstruction Project: | Page | 1 | 2 | 3 | 4 | ||||||||
These are a series of renders of a 3D model I'm working on with the goal of producing a short, photorealistic video of Opipeuter inconnivus, an Ordovician pelagic trilobite. As you can see, the eyes were huge, the body tiny, and as near as I can tell, the legs unknown. I'm basing my reconstruction on two views of Opipeuter published in Richard Fortey's book "Trilobite: Eyewitness to Evolution", as well as the originals of those inks, and a number of photographs of fossils published in the original description of the creature by Dr. Fortey in the journal Paleontology. Much of the detail of the eyes will have to be handled in texturing, as it's too fine for modelling. A paper by Tim McCormick and Richard Fortey on the eyes of Carolinites and Pricyclopyge has given me many ideas on how to represent the look of the many lenses, especially the anisotropic look of the eyes as the creature moves past the camera. As to the color of the body, that seems an open question. At the moment, I'm leaning toward a greenish texture suggested by an encyclopedia photograph of the arctic isopod Glyptonotus antarcticus, but this could change. I probably will not represent it as transparent, like krill or many modern shrimp, simply because of the vast amount of both extra work and extra, unsupported speculation to represent internal organs.The leg anatomy represented in the last image is based on a generic trilobite cutaway image by S.M. Gon, from his wonderful and informative site, as well as my own observations of the local horseshoe crabs and a batch of triops I'm raising in a tank to serve as a model for the swimming style (frenetic, and as much upside down as right-side-up) and for the color and motion of the gill-legs. I'm a little vague on gill anatomy (two gill fringes on the spur or one?) and whether Opipeuter, as a pelagic trilobite, had paddles on the legs or just the standard trilobite leg anatomy. When I'm a little clearer on the anatomy, I'll clone out and adjust all the legs for the critter, but it makes sense for now to only work on one, rather than all 22....
On the tech-y side, this is all an exercise to learn the intricacies of the 3D program Maya 4 from Alias/Wavefront. The surfaces are all subdivision surfaces with the exception of the base of the leg, which is polygons to allow for the use of Maya Fur to portray the gill fibers. Because this is the first time I've used the program, it's been slow (three months so far) but my speed has been increasing with my proficiency. I hope to have a mostly completed movie by September 2002, and I will probably post a small version of it here, if I can get the size down to manageable levels.
Any comments, criticisms, or helpful leads are much appreciated.
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Well, I've finally done some more work on the project. I haven't been lazing around, just trying to overcme some technical glitches in Maya and gather more information on Trilobite legs. In that regard, I've gotten some invaluable advice from the above-mentioned S.M. Gon, as well as finally getting a mail-ordered copy of Ricardo Levi-Setti's book "Trilobites", which, besides being absolutely fascinating, contains the finest photos I've seen of fossilized trilobite legs, Who'd have thought that their legs would be so long? Certainly not me, because I was thinking of them as more similar to Horseshoe Crabs than fleas or isopods. It raises all sorts of questions about what the attitude of the limbs would have been in life, as opposed to the squashed aspect they have as fossils. Given the enormous head of the model I'm working on, as well as its genal spines, I'm leaning toward portraying the limbs as held largely under the body, rather than splayed to the side, as they would be in modern crabs. Held to the side, they would whack their legs and the delicate gills against their shells all the time, so it seems unlikely. Were the legs much smaller, they wouldn't have been able to function as efficient propellors for their pelagic lifestyle. I'm posting two new renders--one of the newer, more gracile leg design as suggested by Dr. Gon, and the other of the leg design in position on the Opipeuter body. For technical reasons, I've had to position the leg as broadly held rather than more vertically, as it will be (I think) in the animation. As you can see, the spread of the legs would impinge on the genal and the pleural spines, a distinctly unlikely position.
As usual, any comments are appreciated (and probably acted upon).
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Well, after a little more jiggering with transparency and specularity maps to make sure that the gills looked more comb-like and less feathery (they do have to have the water pass through them, not by them), I've rendered out a small movie of a leg doing a 360-degree rotation. No natural movement, just an attempt to see if the effect of the visibility and bump maps worked from all angles before going on to try to establish textures for the whole body. The gills are not necessarily going to be pink. That was simply for visibility and convenience. Their color will change when I get a better idea of how the creature is going to be colored overall.
The movie is under 200K, , .mov format, and uses Sorenson 3 compression. As such, you need Quicktime 5 or better to see it. You can get it for free from Apple.
Click the picture below to download the movie.
Pathetic, isn't it. A month spent trying out different leg orientations and scales, and still nothing really works. The gill fibers just seem a little small to me, the legs, a little too large. Viewing and reviewing the video I've made of the Triops I raised (now deceased, having lived their two-score days, and residing comfortably in an acetone bath in an old caper jar) I'm convinced that the overall effect of the trilobite legs should be more "skirt-like". an effect caused in the triops (see the movies below) by more diffuse and broad gill surfaces. I'll have to take into account triops' adaptations for low oxygen, high-temperature water, but I still think the gill surfaces of my trilobite oughta be bigger....Sometime in the next few days, I'm going to haul out the microscope and do some sketches of the limbs of my preserved triops. Perhaps a good high-resolution view of a biramous limb will make apparent to me what I ought to do to get the trilobite legs to look correct....
A short movie featuring one of my triops. Filmed in a petri dish on a specially-built, fiber-optic cool-lamp lit dissection and observation microscope. Filmed in short duration segments, and restored to its tank in between. NO TRIOPS WERE HARMED IN THE FILMING OF THIS MOVIE! In fact, this particular triops was the one that lasted the longest: slightly over the mean life-expectancy of a triops.(n.b. "mean" in two senses...they live anywhere from two weeks to, at the Methuselan outer limit of triops longevity, six weeks. Paltry, but hey. they've been around for something like three thousand times as long as the human species, so who are we to sneer?)
The somewhat dodgy image quality was caused by several things. First, a lousy image capture program that Sony uses to transfer video from its Handycam Hi-8 tape models into computer-readable format. For one thing, it only works on Windows (I've got nothing against Windows, it's just that at the moment, my Windows computer is a lot older and slower than my Mac), and for another, it does a vicious, unavoidable MPEG compression on all imported video, much to the detriment of the image quality. It may be fine for filming Junior's first birthday, but I don't recommend it for serious data. Unfortunately, I also don't have the bucks for a professional video-capture card either. The second factor affecting the image is an older CCD device hooked to the microscope. It had much lower resolution than the native, more modern CCD in the camera itself, as you can see by comparing the above and below images.
A quick test render of the current state of the model. The limbs seem too spidery to me. The biggest difficulty has been trying to figure out the size of the limbs: approximately four pair of the limbs must fit under the head-piece, and while they may move less than the propelling limbs (see the above triops movie) they still have to have a similar structure to the propelling limbs. This is what is meant by trilobites having non-differentiated limbs.Hopefully, a clearer view of a triops limb, from the front rather than the bottom or top (a view impossible to get while the triops is alive without harming it, which I wasn't willing to do...I got sort of attached to them) will help me finally clear this difficulty up.The blue light and fog were an easy way to give the scene some semblance of "underwater" look, both to see how it might eventually look and to give myself a needed boost in feeling like something's coming along.
Darn, this is taking a long time.....
On the technical, Maya side of things, there have been some changes. The eyes are no longer subdivision surfaces, but are now NURBS surfaces, a smoother, "lighter" surface format that's easier to keep smooth and easier to manage textures on. Everything else is now subdivision surfaces (necessary because of the complexities of shape and my lack of patience with stitching NURBS...oh for a free copy of Maya 4.5 with the ability to translate seamlessly from subdivision to NURBS directly) because I'm no longer going to use MayaFur for the gills.
April 9, 2004
Finally, some progress! After five attempts, I have finally succeeded in raising a fairy shrimp to full size. The first two attempts resulted in tanks filled with water-fleas and algae, the third attempt went well, however I didn't notice the triops hatchling until it ate all the fairy shrimp hatchlings. Fourth attempt: more algae and Daphnia. For video see the next page.