Segmenting the Canine skull, part 2

I feel like I got a goodly amount of work done on the skull today.  Even if I'm still floundering a bit on where suture lines are. 

Canine skull, end of day 2

I have around 32 different photo references I've pulled from the net, including one where the different bones of the skull have been painted and labeled. 

A very useful powerpoint from the Calgary Association of Veterinary Students.  This is a screenshot from a slide.  They also have the same skull with dorsal, ventral, and rostral views.  I refer to this a lot.



Of course, every skull has some amount of variation.  And I'm not even sure of the breed of the dog scanned.  However, it is a long snout breed, at least.  Those seem to be more common on the internet as well.  I have the feeling that the dog I have is an older example, as sutures tend to become less distinct as individuals age.

I have succeeded in pulling out the mandible, mandibular teeth, nasal bone, incisive bone, zygomatic bone, maxillary teeth and most of the maxillary bone so far. Truthfully, I've been having a hard time even getting a comprehensive list of all of the bones that make up the skull.  It's somewhere between 22 and 50...  Ah, google.

So, I have done three things to rectify my lack of knowledge.  First, a library!  I found a library on Stanford campus that has numerous canine vet books that I should be able to check out.  Second, Amazon! I also found a fairly inexpensive book (creatively called Dog Anatomy, by Peter Goody) on amazon that I decided to buy... I must admit that I turned to Amazon before the library, so technically these are in the wrong order.  However, the prices on Amazon made me sit back and realize that there are much better ways I would like to spend my money, bibliophile tendencies aside.  Which leads me to my third choice, eBay!  Yes, I am now the proud owner of a dog skeleton.  This makes me happier than I probably should be.

My text reference should arrive on Tuesday.  And in the mean time, I've been segmenting. 

Putting the roots on the mandibular teeth.

The newly added mandible and mandibular teeth.

Trying to figure out the nasal and incisive bones.  I can't tell you how tricky those were.

Adding the maxillary bone.  My skull is starting to look colorful!

 

This is often how I work - multiple views, with the 3D preview to the side.  Because I am having such a difficult time spotting the suture lines, I am relying upon a combination of CT and 3D to figure out where different bones are.  This is why I feel an actual skull is so necessary, at least for me.  Then I will be able to trace the sutures on the physical specimen.

I'm off to the library tomorrow, to further my knowledge of canine anatomy.  I do feel a bit nervous, having started this process without hearing from the actual official people... And truthfully I got a little segmentation happy.  I meant to write my proposal this weekend, not segment canine skulls.  So, realistically I should take a step back and figure that out.  Ick.

Segmenting the Canine Skull

Despite not actually heard back from anyone official on the project idea, I decided to do some segmenting.  Yes, this is what I do for fun on a Saturday night.

The bane of my segmenting existence - ethmoid type bones, and turbinates

I am not looking forward to the canine nasal cavity.  There are a lot of delicate structures in there, that are very, very hard to segment out in Amira.

Canine skull, from an awesome person on deviant art

I have started on other, potentially easily to identify bones on the skull.  However, I've already run into issues there.  The scan I am using, while beautiful, doesn't have the clearest suture lines.  I'm switching back and forth between the three views (sagittal, coronal, and axial) and often viewing the scan side by side with the projected 3D model.  This allows me to see my changes in real time, so I can compare with reference texts and photos.

Amira 3D point cloud

Trying to identify the jugal bone

And the bones of the canine skull are different than those of a human.  So, while the experience I gained segmenting out many, many skulls at my previous job is helpful here, I am struggling somewhat with where suture lines are supposed to be.  I would love to get my hands on an actual skull.  Which is an idea to run by my vet expert....

EDIT: 4 hours later, I'm starting to feel some concern.  I chose what I thought would be 'easy' bones to start off with, but... it has been around 3-4 hours of work and I'm just now finishing them up.  And I'm fairly certain that the lacrimal bone is in there somewhere.  I'm hoping that I just misjudged what would be less difficult, and not that the rest of the skull will be even more complex.  I definitely need a physical canine skull.  Photo references are all well and good, but an actual skull would be much more useful.

Zygomatic bones in red.  (It would be helpful if all of my references agreed on the bone names.) 

 

Dog Anatomy 3

So, I fall afoul of deadline dates once again.  I had to submit my work on the canine Anatomicae contest this morning - and I don't feel like I've finished my final piece.  However, isn't the cliche "when do artists actually feel like they've finished?"  Truthfully, there have been some pieces that I really do feel have been completed.  But, this is no where near one of them.

Some WIP shots.

Color blocking in the silhouette and choosing some colors to work from

Basic shading added

adding in a very rough background and refining the shading - her paw looks amputated right now

tried to work on her eyes and the paws.  Got some reflected light going on, but it's not quite there.

The image itself is still very rough - blocky shading and such.  Her eyes aren't quite right, and the background is atrocious.  But, this is where I got to in two weeks time, while also working and doing the paper mache eye, etc. 

The contest itself required a pose that showed all four legs.  I wasn't completely aware of that when I did my anatomy sketches... But I do plan on including the anatomy for this pose as well, when I get the time.  Perhaps in between paper mache layers?

- SH

Dog Anatomy 2

So, I'm back again with some more canine anatomy studies.  Today was also a study in the adage 'save often' - Photoshop crashed and took my entire skeleton and muscle system with it.  Go figure.  But, I recreated it in a much rougher form and I'm still going to share it.  These studies will eventually be turned into an actual dog.  I'm torn between an action pose and the sleeping pose for the final piece.

Sketching from a photo of Oshie.  Rough sketch.

 

Refined the rough sketch just a bit.

 

Grabbed some more skull references in addition to Ellengerger's Animal Anatomy book and drew in the skull.  Nothing was in the exact right pose, but I'm feeling a little better about canine skulls in general now.

 

I started to rough in the rest of the skeleton.  This is the last stage I had saved before the crash.  I ended losing all of the finished skeleton and most of the muscles.

 

 A much rougher overall skeleton to replace what I had lost.

 

A 15 minute color study of the skull.

 

A very fast muscle study again.

 

I'm just about ready to move on to a final pose.

Dog anatomy

I'm doing a series of images right now with canine anatomy.  Here are some of the sketches I've done today.  The first two are done by observing An Atlas of Animal Anatomy for Artists - a book that I haven't done enough studies out of yet.  Then, I started to sketch my dog, Oshie.  I topped it off with different rapid positions of her both in repose and in action.  Finally, I tried to lay in the proper skeleton in one of her action poses.  The angle was a little strange, so I may need to revist that one as I continue.

Ellenberger pose study - bones

 

Ellenberger pose study - muscles

 

Oshie face head on

 

Oshie face - looking up

 

Oshie studies - laying down

 

Oshie studies - action

 

Action pose - bone placement

  

Action pose - bone with color

 

Action pose - muscles 

(EDIT - I forgot to add the skeleton and muscles sketches to Oshie's 'action' pose)