Monday, June 29, 2009

The Next Time Capsule

It's that time already. Time to announce the next upcoming Time Capsule gallery.

By popular demand, as determined by our gallery poll on the sidebar, the subject of our 2009 invertebrate themed gallery (expect at least one more themed gallery before new years though!) will be...



The first super predators of prehistory, the Anomalocaridids. Made famous by Stephen Jay Gould, along with their palaeo environment of the Burgess Shale, in his book A Wonderful Life. These bizarre shelled arthropods had a unique body design unlike anything alive today. With mushroom stalk like eyes, spiked tentacle like appendages off their snouts, a pineapple shaped month on the bottom of their head, and a strange lining of fins down both sides of their bodies they are a interesting challenge for any palaeo-artist.

Remember we're hoping for submissions of any and all, qualities and abilities, from anyone and everyone with even a vague interest in fossils of palaeontology. Send your submission(s) to artevolved@gmail.com.

If you are looking for some ideas or inspiration be sure to watch out for our Anomalocarids in art post with previous artwork depicting these amazing creatures. We also to see much more in depth discussion like those seen with the upcoming Pterosaur gallery.

Also be sure to vote on the gallery which will follow the Anomalocaridids in November. The poll can just be found to the right on the sidebar.

Thursday, June 18, 2009

Dr. Mark Witton weighs in on Pterosaur wings

It seems our recsent discussions on Pterosaur reconstructions, in particular wing attachments, has attracted the attention of at least one expert, Dr. Mark Witton. (To catch up on these discussions, they can are in the comment sections of these posts here and here).



For those of you who have never heard of Mark Witton, he is an English Palaeontologist who specializes in Pterosaurs. He has done a lot of collaberative work with internet biology/palaeontology guru Darren Naish, but also made several discoveries on his own.

Of more interest given our palaeo-art spin here at ART Evolved, Dr. Witton is an active (and very talented, I might add) palaeo artist. You can see his work here on his flickr page (including a Pterosaur gallery). The lovely picture above being a more outlandish example of his work (I choose it as I'm under the impression the young man bending over to retrieve his hat is a self portrait of Dr. Witton).

Given his expertise in both the scientific field of Pterosaurs and also in how to reconstruct them, he wanted to add his opinion to the discussion. As he lacked a google account Dr. Witton emailed our member Zach, who himself was unable to post the email. So I have been entrusted with this task.

So without further ado Dr. Mark Witton's comment:

Hi Zach,


I was just checking out some bits online and came across the ART Evolved website. Seeing that you're doing pterosaurs next, I checked out what was being said and noticed that there were some discussions about membrane attachments. Seeing as the concensus between your commenters was that there was no concensus, I think you need to reconsider your ideas.


There are at least 3 reconstructions that are regularly discussed, but only one is worth any salt. For this reason, all my papers (at least, unless I've totally forgotten something) say that the ankle-based attachment is best supported.


Look, here's a quote from Witton and Naish (2008):

"...evidence from anurognathids, campylognathoidids, rhamphorhynchids,> ctenochasmatoids and non-azhdarchid azhdarchoids [86]–[91] indicates that ankle-attached wing configurations are more accurate."

In a nutshell: there is _no_ support for a supports a hip attachment, one specimen may show a knee attachment (but it's ambiguous at best), whereas specimens of Eudimorphodon, Anurognathus, Jeholopterus, Rhamphorhynchus, Sordes, Beipopterus and a tapejarid (at least, there may be some I've forgotten) all give either hints of an ankle attachment or show it quite convincingly.

Hence, if you draw any other type of brachiopatagial attachment on your pterosaurs, you're ignoring the wealth of evidence in it's favour.

Darren Naish gave more detail on this a while back, and not much has changed since then: http://darrennaish.blogspot.com/2006/05/pterosaur-wings-broad-chord-narrow.html The question of membrane shape has is different, nowadays: did they taper in close to the body before hitting the ankle, or extend in a broader fashion?

That's a considerably harder question to answer. I did try to put this on the blog, but I couldn't post it as I don't have a Google account. In any case, it may be an idea to pass it onto your chums so everyone has the same data. Anyway, I'm looking forward to seeing the results, and I might have something new for my own site up soon. Ish.

Cheers,

Mark

I apologize to both Zach and Dr. Witton if I garbled the formatting here a bit. The version I received was a HUGE mess, due to gmail replacing spaces and enters with "<"s.

Friday, June 12, 2009

Making of Karoo Sunset

As you've no doubt noticed ART Evolved has started to be consumed by excitement over the upcoming Pterosaur Gallery. For really good reason too. Pterosaurs have always been a huge icon of prehistory. So be sure to get started on your entry for the gallery today!


However I'd like to return to the Synapsids one more time, before it is nothing but flying reptiles around here ;p


Following Zach and his examination the creation of his own entry, I wanted to similarly share the process behind my own Synapsid piece. Where Zach approaches his with some regret (I personally think he is being too hard on himself, but I know the feeling. We are often our own worst critics!) I come at my own much more pleased.



The piece in question is this, Karoo Sunset. I aimed to have a picture that looked like a snap shot of the life in the day of. Unlike usual though, I actually ended up with something resembling what I'd intended.
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After reading Peter Ward's book Gorgon (my brief review here) I felt inspired by the late Permian and the creatures from then we find in South Africa (the Karoo region in particular). Among the few well known and famous animals of this time and place were the Gorgonopsids, so naturally I wanted to recreate them.
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I had in my mind a scene with a pack of these animals settling at sunset (though there isn't any real evidence I've read about indicating they were social). In that initial imagined state I imagined the piece as a lot more close up and tight then it ended up.
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However despite it "opening up" all the key elements ended up in the final piece. An animal nawing away at the day's kill, youngsters tumbling around in play, several starting to doze off, and a larger adult showing off its freightening teeth in a big yawn.
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Though the scene worked out well, I certainly didn't have a plan that lead me to this end product. In fact to be honest I mostly fluked my way there...

video

Of course the first step was to build a Gorgonopsid. As I work almost exclusively in 3D CG, I'm quite literal when I say build.
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I was thinking about ART Evolved while building my Gorgon's head (the first thing I tend to build on any animal), and so documented nearly every major modelling step I took to create the skull and jaw. You'll find it all compiled into this little slideshow.
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This was in total about 45min to an hour of work. It is kind of depressing that it all compresses into 30 seconds so easily...
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Sadly Gorgonopsids being Synapsids have fairly boring skulls from a construction point of view. They don't have the fun holes and openings of reptilian skulls like Dinosaurs. So if people find this animation neat I'll record the next Dinosaur I build so you can see how a more complicated build comes together.

This one had only one minor 3Ding drama, that being the eye placement. You can see me correct this around 21 seconds.


Anyways with the beast built now I needed to texture it...

This ended up being the most difficult phase in the end.



My first problem was I couldn't decide on what I wanted it to look like. Was it going to be scaly with just some tuffs of fur, or was it going to have a big woolly coat.
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In the end due to my embarassing attempts at scales with tuff of fur, I opted for just a hair covering.
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With just a hair covering, creating the baseline model texture was stupid easy. Just this simple brown with black random lines, to simulate a base coat of fur, done on a much larger scale.


However this basline was going to need some 3D fur to make it looking convincing. Enter the HUGE problem. Fur...

Now as readers of my other blogs know, I've been doing a lot of feathered theropods lately, and these have really brought some of my 3D Dinos up to a new level. However you'll also find that despite my love of them in the the final product, feathers (and in this case fur, which is just a slightly different application of the same process) are the bane of my existence!
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This was among my first attempts at applying hair to my Gorgon... A very cool effect (one I'll be stealing for any woolly animal galleries we do here in the future ;p) but certainly not a realistic looking Gorgon!

Why the crazy non-fur looking fur?
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I'm using a feature of Carrara called Surface Replication. In it I select any smaller objects (in this case the different individually modelled hairs you see floating above the Gorgon) that I want copied along the surface of a larger object (in this case the various parts of the Gorgon). This feature in theory is incredibly handy, as you can make up to 10 000 copies of the smaller shapes with this utility. Individually placing and modelling that many hairs would take me months (and I just won't do it!).
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However sadly it isn't as easy as you'd hope. There are a number of factors making it difficult. The size of the hair in comparison to the body ended up being a critical issue, and one I'd hit in a really hard way putting my scene together... I'll get back to that soon.

The thing that bugs me the most about this application is that whoever programmed this feature didn't think about the orientation controls. In theory the fur on my beast should align to the master object (again floating about the Gorgon), however somewhere in the math of this process all the X, Y, and Z attributes swap. Meaning that how I align my fur in the "real" world isn't how they align on the creature.
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Which is why he appears so shaggy in these early attempts. Fur (or feathers) that stick out make your critter look unkept and unhealthy. So it'd be nice to have intuitive control on these things to slick them back...
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So after playing with the size to body ratio, and the orientation of my fur...
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I finally got this final version (well okay close to final. I didn't save a shot like this of the final final model).

I went for mostly subtle sized hair, but a larger thicker "mane" around the neck. In this pic it doesn't look so good (as it is also one version before my final one), but in the final piece the manes on the adults worked.

Next I came to where I was going to stick my critters for the scene. The Karoo 250 million years ago was a semi arid desert. Once it'd been a lovely productive forest, but with the number of converging geologic factors caused by the formation of Pangea, the world was slowly being turned into a giant desert...
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This meant that I didn't just need a desert shot, but due to my desire for a sunset, a desert in sunset. As I didn't have any photos that matched this description, it meant I was going to have to construct my own location in 3D.

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Though it was a lot more work then my usual compositing (which is work in and of itself). This would take me a week. However the control this gave me over lighting every element contributed to the awesomeness of the end product.

Building the desert itself ended up being rather straight forward. I went for a mesa valley, containing an increasingly rare lake.
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Where the terrian was trickiest (other then scaling the landscape to match my Gorgons... but that's in a moment) was lighting it. If you compare this early test render to the last, you'll see my conundrum. Sunsets generate a beautiful range of yellows, oranges, and reds. The question is which of these did I want my scene dominated by.
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The other complication in this was how many different lights was I going to need?

In 3D scenes the lighting is completely up to the modeller, and there isn't just one type of light that fixes all.
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I'll probably at some point do a full tutorial on 3D lighting (as I've been learning a lot about it this year), but here is roughly how I lite the scene and solved the color problem.
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In the end the Karoo ended up with 5 lights. The first one is obvious, and one in the real world you'd expect. There is a great feature in Carrara that not only generates the 3D sun you see in the scene, but allows you to make it a light source that mimics properties of real sunlight (such as the colour, brightness, and even clouds... all of these changing on how you position the sun in the sky... so in this case it helped set a baseline sunset lighting).
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However if you think about this position of the sun to my subjects, they'd all be backlite and thus nothing more then silouettes. The other issue I had was with shadow casting.
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To solve the Shadow issue (and a bit of my backlighting issue) I created a general "bulb" light directly above the sun (just above the top frame in the final render) that cast a bright yellow light. Bulb lights work just like a uncovered light bulb, they cast light in every direction.
This first bulb was to lighten up the whole scene, and thus help increase the contrast of the shadows. Due to its better angle I made this my central shadow casting light so all the shadows in this scene aren't strictly scientific from a physics point of view :P.
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This however made the scene too bright. To darken it back down , and yet better light the objects (if that makes sense) from viewers point of view I created a dark red bulb that I placed directly behind the camera. In essence where the picture was taken from.
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This lit the scene perfectly, but the Gorgons were still very dark. To fix this I created a lighter red light that was set to only light the creatures (and their fur! Which I missed in first couple passes at the scene). This is a fun benefit of 3D light, unlike real light, you can make it effect only things of your choosing!
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My last light was for a subtle, but needed effect, and that was the glisten of the uneaten meat on the carcass. This was a nearly white "spot" light, as the pure white mixed with my other scene lights nicely. Spotlights can be thought of as like either a real spot light, or metaphorically like a flashlight. It shot a beam straight ahead of it whereever you point it, but that's it. Only things in that line get lite. In this case just the meat objects on the skeleton.
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All the individual elements were ready. It was finally time to put them together.

When I hit yet another fur related problem! Which you can see here.

Fur and other surface replicators have another annoying catch. Once you've created them if you change the size of the recipiant object (in this case I had to make the Gorgon smaller, so I shrunk its body parts) the fur doesn't change size to match!
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I'd modelled the desert on the scale of 200 units long by 200 units wide. My Gorgon was 40 units long. Meaning it was quite large in what should have been a large desertscape. Attempting to shrink my Gorgon caused this fun fur effect...
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At least my nice lighting obscurred how dumb it is!
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After rescaling the landscape to an impressive 3000 by 3000 units (anymore then that and my lighting won't work... though this week I have a new means to light even a million by million object!) I had to readjust the lighting a bit. Due to the shift in the sun (to get it back over the now taller horizon) the colour shifted a bit, and I couldn't quite get it back. Oh well.
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To increase the feel of realism I decided to make a swarm of flies and shrubs scattered aross the scene. These were accomplished like fur (the flies a slight varation, but not worth going into so close to the end).

The last thing I had to do was import Gorgons (sadly one by one) position, pose, and light them. This took a long time just due to the computational requirments of so many 3D objects.
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It all came to together as this. Hopefully as you've seen with the errors I documented (and the dozens of others I neglected to document) that though this piece is really awesome, I didn't directly set out knowing I'd get it this way.
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However this first immersive lesson in lighting has me looking at this factor a lot lately, and I will probably be able to set out for similar effects in the future.
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What I'm most proud of is that the multi layered lighting has accidentally mimicked the look of a painting. If you can't enlargen this version here is an enlargened version for a closer up look. This is the closest I've ever come to emulating my childhood hero Charles Knight... Now if only I could actually be as good as him :P

Sunday, June 7, 2009

Pterosaur Restorations!

There have been a LOT of questions on this blog about Pterosaur wings and appearance (and a lot of opinions being thrown around), so at Craig's (or should I say Traumador's) request, I've rounded up some pics of pterosaurs to give you all some ideas for your submissions to the Pterosaur gallery. For your artistic inspiration, Paleo-fans and ArtEvolved crew members..........

...Here are some restorations of Pterosaurs over the ages - some accurate, some..... well, to quote Borat, NOT SO MUCH! Everyone seems to have different theories on how Pterosaurs looked, particularly their walking posture and where the wings attached - and there's a wide range of interpretations of the fossil evidence. So I'm posting the whole gamut of them here, and you be the judge. Here are some of the most memorable ones:




A very early engraving of Rhamphorhynchus from the Victorian Era (I can't remember who the artist was, and it's very outdated today - but this was a very popular image in its time - though ironically the head is more like Pterodactylus).



Rhamphorhynchus by Charles Whymper (lol that's a lot of silent h's)



Pteranodon by Heinrich Harder



Rhamphorhynchus by Zdnek Burian. Historically, the "bat-winged" model of ankle-attached wings was very popular as with all of the above images.



Dimorphodon by Gareth Monger



Pterodactylus kochi by John Conway, in a more recent free-legged configuration




Pteranodon stenbergi by Michael Skrepnick (at least a semi-free-legged configuration)




Ornithocheirus with hypothetical "bat wing" model (wings connecting to ankles). Source: Walking with Dinosaurs TV series.




Quetzalcoatlus northropi and the Chicxulub impact by Douglas Henderson (look closely and you'll see the legs are free of the wings).




Anhanguera piscator by John Conway - a prime example of the free-legged model




Tupandactylus imperator by Mark Witton - quadrupedal "bat" model



Peteinosaurus (by an unknown artist) - a cross between hip attachment and the "flying squirrel" model sometimes proposed for rhamphorhynchoids.




Ornithocheiroid pterosaurs by Mauricio Anton (I'm not sure of all the species, but the one on the left looks like Anhanguera or Criorhynchus, while the one on the right is clearly something else.)




Pteranodon models (life size, sculptor unknown) with knee-attached wing membranes based on recent research. The legs look like they have some odd wing-wetsuit on... but overall pretty elegant.




Anurognathus by Mark Witton. Note the bat-like extension of the wings all the way to the ankles.





Four Cretaceous Pterosaurs by John Bindon - Clockwise from top: Tapejara, Tupuxuara, Ornithocheirus, Anhanguera. This painting follows the hip-attached or knee-attached wings model




Zhenjiangopterus linhaiensis by John Conway. (*it's ALIIIIIIVE!*)





Thalassodromeus (by an unknown artist, though the style reminds me of Bindon's)




Pteranodon ingens (female) skeletal by Gregory S. Paul (in Paul, 1991: The Many Myths, Some Old, Some New, of Dinosaurology). Paul supports the theory that the short tail of Pterodactyloids was not totally lost because it was retained as an attachment point for the wing membranes.

A great reference for drawing takeoff poses and modern restorations with wings NOT attaching to the legs.





Quetzalcoatlus northropi by Gregory S. Paul (due to the shutdown of the "Unofficial Gregory S. Paul gallery" fansite, I was only able to find this odd green-tinted copy. I really wish there were a book with more of his art in it.)



Yes indeed, a true color reproduction of a Gregory S. Paul painting - a breeding pair of Quetzalcoatlus northropi defend their nest from a Daspletosaurus. The original of the previous picture showed them with the same colors. This painting gives a good idea of the sheer size of the biggest pterosaurs.




Pterodaustro by Mark Witton. There are very few decent restorations of Pterodaustro, and regardless of personal opinions on wing structure, this is definitely one of the best.



Pteranodon and Hatzegopteryx by Mark Witton
(here we see "bat-like" full ankle attachment, which would have optimized wing surface area, but severely limited the range of movement on all limbs when walking)


As no definitive proof of how the membranes attached has been verified, ALL of the more recent images above (i.e. anything newer than those outdated Victorian-era engravings) involve some guesswork and all of them have to be taken with a pinch of salt ... but they all agree on the basic morphology of EVERYTHING ELSE about pterosaurs. So have fun drawing them.


Hint
: shhhhh....Mark Witton, Greg Paul, and all the "experts" don't want me to tell you this... but this is what pterosaurs REALLY looked like (:P)


``******+**** <> ****+******``
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Just kidding. Well, there's my cheesy little unicode Pteranodon! lolz. Seriously though, don't draw them like this.



AAAAAAND.... for those of you REALLY curious as to how most people would not draw a pterosaur, I give you....


Koseman and Conway's Pterodactylus inspired by David Peters' research

[The caption that accompanied this piece has been removed by ART Evolved's Administrators due to the editorial commentary causing offense to the artist in question.
Our apologies to David Peters for any offense this commentary may have caused him.. However in the defense of our member who made these comments, they were not derogatory of David Peters as an individual, but rather just this piece of art itself and the scientific logic behind it.
We have changed it as per Mr. Peters request in the interest of resolving this disagreement of opinion in a civil fashion. As it was of a scientific nature, it goes beyond the art mandate of ART Evolved, and we are not wishing, nor capable of resolving it adequately on this site.
We thank Mr. Peters' for his interest in ART Evolved and hope he will consider contributing more to the site in the future.]