Tuesday, November 17, 2009

Reconstruction Tips: Extant Referencing

Welcome to yet another edition of...

Today we bring you the first ever self contained Reconstruction Tips.
I [Craig if your wondering] share some tricks that helped with my biggest palaeo-art achievement yet.
I owe it all to this piece by Julius Csotonyi entitled "Tylosaur and KT Event".
I have been obsessed with Mosasaurs for the past decade or so. I just find the idea of marine Monitor Lizards (and/or possibly limbed Snakes...) fascinating. I mean come on, a Komodo Dragon with flippers that swam around taking on sharks, how is that not the coolest thing ever?
The thing is I had never found a restoration of a Mosasaur I was ever been 100% happy with. Don't get me wrong, there are some great Mosasaur recreators out there. Dan Varner in particular deserves special mention, as do the CG ones from both Nigel Marvin's BBC Sea Monsters and National Geographic's Sea Monsters (apparently you have to name any moving picture project with a Mosasaurs in it Sea Monsters... not that I disapprove ;P ). Yet few recreations of these marine reptiles have ever completely satisfied me.
Then I found this Csotonyi piece, and the reason for this dissatisfaction slammed me in the visual cortex. No one (until Csotonyi) had ever tried to completely tie a Mosasaur to its Monitor Lizard roots. Despite the bold new direction he'd taken, I felt that Mr. Csotonyi's concept could be taken a little further...
Of course a concept is easy to picture in ones head. Getting it out of the mind and into the material world for others to see, that is the trick.
How was I to take my friend here, the Australian Perentie Monitor (Varanus giganteus), and essentially turn him into a Mosasaur? (I choose the Perentie as I have several great reference pictures of a stuffed one in the Sydney's museum, and I love its colouration. If I had better pics of the Nile Monitor (Varanus nilotictus) it would have been in close contending).

This is the answer I came up with to this challenge.
Now as I'm sure many of you know, I am typically dislike to outright hate my own work. With my Tylosaur here I'm not just pleased with this critter, I'm down right proud of it. I somehow managed to arrive at nearly the exact point I aimed for!
It was not outright luck that brought me to this conclusion either. Rather using a combination of artistic skills (I've been building through the motivation provided by ART Evolved), and more importantly the judicious application of referencing and scientific research.
Though this Tylosaur model is miles ahead of my Squalodontid whale, it owes its existence to the lessons I have been learning through my whale mistakes (read about those in my Flukes series of articles). I'm jumping the gun a bit, and this article is essentially a preview Flukes part 3 (coming soon), but with better illustrations.
As a quick aside for you more technical minded people, I accidental refer to my Tylosaurid here as a "Mosasaur" a lot. This is a force of habit from tour guiding, where I simplify rather then specify things. I use the term Mosasaur in the overall family sense, and by this logic I am correct as Tylosaurs were just a specific branch of this family. In cases where specifics I mention are only true about Tylosaurs and not other Mosasaur subfamilies compared to Monitor Lizards, please keep this habit of mine before losing it at me. Thanks :p
Before I could start on Monitor Lizarding a Mosasaur, I had to understand how both animals were put together. What were their similarities and their differences?
Skeletal references are the only way to understand these, and as of such I tracked down as many of these for both groups as possible. Fortunately Monitor Lizards and Mosasaurs have a healthy representation on the net. Not all non-Dinosaur prehistoric creatures enjoy this (like say Squalodontid whales!), and it can really slow you down with obscure critters.
When acquiring these references from the internet it can be quite hard to find pictures of the right or comparable angles for direct creatures and fossils.
Hint! Whenever you are visiting a zoo or museum take as many of your own reference photos as you can! Of anything and everything that you find interesting, as people on the web may not have the same tastes as you!
I focused most of my effort on the skulls, as I've been learning 75% of a solid restoration relies on its head, and Mosasaur and Monitor Lizards differ post cranially in some drastic ways (especially in the neck region).
As I was aiming for my Mosasaur to look as much like a Monitor Lizard as possible, I also required a fleshed out Monitor Lizard to visual focus my effort on.

So here is a rough flow chart of my initial findings of Tylosaurs vs. Monitor Lizards.
Hint! Before comparing references make sure you pick one common parameter to scale them on. In this case I picked the length of the skull, but I could have instead chosen the height. It is important to pick a single parameter, especially when using more than two references. Otherwise you may get some of the details wrong.
Modern Monitors' heads are much taller proportionally then the Mosasaur. You can see this in the middle of the chart where I have overlay en the Mosasaur skull over both the Monitor's skull and head. To accurately use the Monitor as base of a believable Mosasaur I was going to have to alter it to match the Mosasaurs dimensions.

Photoshop-like programs are an incredibly helpful tool in comparative anatomy research. I'm talking about before you ever tackle the art end of a project mind you, no matter your medium. There is just so much you can do to your references within these programs.
Here are some of the good things to keep in mind when bring your references into Photoshop:
  • Always copy and paste your references into a new file. This way if you screw up or heavily alter anything you don't have to re track down your baseline reference. This might sound simply, but forgetting it even just once can be devastating (especially with your own personally collected references!)
  • Put each element into its own [raster] layer. This way you can easily control and manipulate each reference without effecting the others!
  • Remember when saving these files to make a Photoshop file version so that your layers remain separate. If you forget to do this, and save them as a jpeg of gif your elements will merge, and you will have to separate them again (if they don't overlap!)
So the Monitor lizards were too tall (with my chosen parameter of skull length). Easy enough. I went in with photoshop and reduced the height of my Monitor so that it roughly matched my Mosasaur. You can be as picky or accurate as you like matching these up, but I just needed approximate.
All I was trying to see was how and where the skulls matched and mismatched. They had their mismatching areas I had to keep in mind, but overall they aligned spectacularly.

Hint! To really see how things align, remember your layer transparency settings! These are incredibly handy for looking through one reference onto others directly behind it. If you keep your references on separate layers, transparencies do not have to be permanent either. You can just lower or restore the transparency as needed.

A similar adjustment to the fleshed out monitor skull, and I had a solid visual of what I was aiming to create.
Here is the flow chart of the various comparisons I did with the Mosasaur skulls. I omit here the same tests and checks I did with the photoshopped Monitor Lizard skull.
With my altered fleshed out Monitor Lizard head reference I got to work sculpting and modelling this counterpart 3D Mosasaur. To follow this artistic process click here to follow my WIP posts of this work.
Along the way I of course did several double checks to ensure my Mosasaur, though modelled after a Monitor Lizard's head was still matching my Tylosaur skull. (The overhang on the chin is my saving a bad version of this comparison. The Mosasaur skull overlay is slightly too big, in both length and height in this particular image. I forgot to save one of the good takes, but you get the idea I'm hoping).

All things considered, I think I did a pretty good job. Not perfect mind you, but that is partially lighting (this Mosasaur is currently bathed in modelling light, unlike the artistically lite stuffed Monitor Head in the museum), and I still have some fine tune modelling of wrinkles and folds to do.

So look for this fellow in the upcoming Palaeo-Environment!

Hope this look at using extant references was a help, and gives you some ideas for your own restorations!


Albertonykus said...

Pretty sophisticated stuff! No wonder you're proud of this one!

Nick Gardner said...

Caution, monitors are very variable (it's a huge family, tons of species), and that cast that you're using for comparison isn't necessarily the best reference skull.

Many monitors don't have such proportionally tall skulls.... check DigiMorph for more accurate references. Some do have really boxy skulls, and others don't.


Weapon of Mass Imagination said...

Thanks for the warning Nick.

Though you look carefully at my Tylosaur's head, I've kept the skull and jaw proportions of my reference fossil pretty dead on.

I wasn't using the Monitor as my absolute reference. More as a stylistic one. I simply wanted my Mosasaur to convey that it was once exactly like the Monitor, but not ANYMORE, if you follow.

Using my distortion technique in this post you could make any Monitor's head, no matter its proportional difference, close to a Mosasaur. You just have to make sure you are matching the right parameters. (In fact a slight confession, for this tutorial I grabbed the higher res pic a Komodo Dragon skull, rather then the Perentie skull, to include in the pictures. The Komodo Dragon's skull isn't AS tall as the Perentie but is still way taller then a Tylosaurs. I didn't come across one Monitor that matched without photoshop manipulation)

The key difference between Monitors and Mosasaurs (which I kept in mind) is that Monitors as a rule tend to have taller skulls vs. jaws, where Mosasaurs are the opposite with pretty massive lower jaws (especially Tylosaurs, which I was doing). Also Mosasaur eyes are universally further back on the skull then Monitors, which themselves have eyes set (typically) pretty close the the middle of their skulls.

I'm sure you knew all this last part Nick. I'm just stating it here for the benefit of others joining in on the comment section so they know what your concerns were about.

Thanks for the interest in the technique, and I'll be checking out DigiMorph for sure. Hope to see you around here more.

Any suggestions about the Tylosaur I ended up with.

lisabiziou said...

this is such a totally fantastic looking and intreasting blog.

i hope i get this good one day, but i manage 4 a 5 blogs and do it alone