Dinosaur Replicas - dinosaur bone models + Styracosaurus skull W.I.P.

tarnyloo73

Active Member
Change of pace, I've been on with this thing way too long now and it's time to have something tangible, I'll see if I can get some bone models ordered and work on the life bust while I'm waiting for them to ship.

before I can upload to Shapeways, there's some production work to do on the model. My usual workflow goes something like this.
  1. poly reduce the main parts
  2. make and test extra structural pieces, connecting sprues, jaw joint fittings etc.
  3. weld it all together
  4. create correctly scaled versions
For uploaded models, Shapeways allows a max of 1 million polygons but they prefer 0.5 mil or less. Personally I like to get the polycount as low as possible without compromising detail, occasionally it's tricky to get models past the qualifying checks. When issues arise it's usually an iterative process tweaking the mesh untill it's printable so I want small file sizes for faster uploading.

I've made fair progress this evening and I'm half way through step 2 finishing up the jaw joint. I've have to remove some small areas from the skull and jaw for the pivot parts (red objects) to work. The black wireframe wedge is a cutter object doing its job on back of the cranium.



Lower jaw is a simpler affair, I'm just going to sculpt down a small area until the hole in the joint knuckle is cleared.

 

tarnyloo73

Active Member
I'm going to exploit the flexibility of Shapeways plastic materials by using a spring tension joint for the Jaw. The articulation points are bent outward slightly (7° each side). To fit the jaw in place you have to pinch it slightly at the back, the tension will hold the jaw in position whatever angle you pose it.



I've learned through experience to add some transverse bars to increase stiffness and stop the front of the jaw flexing. That's this part ready.



Got the sprues ready to connect cranium and jaw, the blue object is for drilling out a mounting pinhole under the brain-case. Next job is to sort the neck, might be a bit tricky.

 

tarnyloo73

Active Member
That's a production version of the head ready (I hope).



The neck is a bunch of floating bones, 9 cervical vertebrae and 16 neck ribs. I wanted to connect them into a single mesh and for the connectors to be as inconspicuous as possible so I spent some time making a central connecting tube (red) and small struts to attach the ribs (blue). I also wanted to reinforce and reduce flex so there's also some discrete connectors at the top (yellow). The magenta block will connect to the head.



Just got to weld this together and make a head/neck version but it'll wait till tomorrow. Got the foot to do too.
 

tarnyloo73

Active Member
Had a few days off this, been a bit distracted by an event hosted by my hometown over the past week. Got some prints of my rex bone models ordered, should be arriving in a few days. Finally persuaded myself to make a start on the lipped rex.





Got the details to a mid-level I think, I'll review in the morning and then add some smaller scale texture.





I want to keep this version fairly conventional (to my taste anyway), kind of a classic looking rex. I definitely want to make a 'no lips' version too, just want to get this one past the post first.
 

tarnyloo73

Active Member
Think I'm just about finished with this one now. Surface texture may appear a little heavy but that's deliberate. Experience with SLS prints has taught me it helps to punch up smaller details so they register through the grain.





Having the bones inside the life bust has proved to be a useful constraint that helps to prevent errors in form.





Fairly conservative ornamentation for the snout ridge. A low central row of rectangular scales surrounded by more pebbly ones.



A kind of devil horn on the postorbital with more of those chunky pebble scales on the upper rear of the head.



Think I'll add some scars on the face and a few toothy indentations here and there and call it done.

 

tarnyloo73

Active Member
Battle damage completes it really well! Well done.
Glad you like it though after checking back today it looks really painful! :D

- - - Updated - - -

Been making some bits n' pieces for the life/bone version. If it isn't clear the parts are as follows -the magenta block bisects the head, the green is an inner sleeve to hollow out the model with small peg holes to attach the skeleton half and the small blue parts are to cut a mounting hole.



It'll take some boolean operation clean-up to get this working properly and hopefully I'll be able to post a visual update soon.
 

tarnyloo73

Active Member
Well it all went together fairly OK, couple of tricky bits to sort through but this should work.



Normally I would add sprues to join the 2 parts but I'm not this time 'cause I want to keep the surfaces clean. Just got to get it through Shapeways mesh checks then I'll get a 1:20 scale ordered.
 

Too Much Garlic

Master Member
Pretty cool to see the half and half model.

Do anyone know where I can find the pictures of the T-Rex skin impressions that were found? I can't seem to find them.
 

tarnyloo73

Active Member
Do anyone know where I can find the pictures of the T-Rex skin impressions that were found? I can't seem to find them.
Most skin impressions used to reconstruct T.rex come from close relatives. The most famous one from an actual rex comes from a specimen known as Wyrex, it's a small patch of pebbly scales. There's also an infographic kicking around the net that combines all the data on Tyrannosaur skin though there seems to be multiple versions of it.

Try this link and scroll down the page.

- - - Updated - - -

Made a start on the non-lipped version today. Taking inspiration from the paper by Carr et. al. I'm going to have a go at croc-style cracked facial skin.

Just a couple of modifications to the lipped rex low-res cage to make a sculpting base. The poly loop I'd added around the mouth for lip definition gets removed here, I've had to move the UV seam (red line) inward and a little UV clean-up was needed. Some final adjusts to the mouth and it's good to go.



That little ngon I used above the previous version eye to add definition turned out to be overkill so for this one I'm updating to simpler topology.

 

tarnyloo73

Active Member
Grabbed some time with this today, making a half-hearted effort to keep things similar to the lipped version.



A few differences though, just for contrast. Eye horns slightly different and a more prominent nose ridge. Of course it should really become distinct from the lipped rex when I texture the face.



Tooth line is a bit simpler to shape on this version. Trying to wrap the oral tissues around the teeth in a croc-like fashion.

 

Too Much Garlic

Master Member
One thing I've always wondered was whether there was any basis for the inside the mouth membrane at the back of the mouth, instead of just having the lip continue up and close that section as seen in mammals? So basically not have the dip in at the back of the mouth, but have the skin close things up outside the bone.

Just as a side note, your sculpt kinda reminded me of the following one from the Trey the Explainer video *Did T-Rex really have bad eyesight?*. I always liked that one. :)
Did T-Rex really have bad eyesight.png
 

animator

Active Member
This is coming along really well! I love all the research and thought that went into this project. I learn more about dinos every time I check this thread.

When you mentioned booleans it reminded me of when I was first learning to model in 1997. I used multiple booleans to attach parts of my first digital character together (a bad idea, but my modeling teacher didn't know much). Anyway, back then if you clicked boolean, you just got up and left the computer while it "thought" for 20-40 minutes and decided if it was going to work or crash the program (3DS Max 1.2). Booleans were successful maybe half the time at best for me, mostly Max crashed and I lost an hour.

Software and hardware have both come a long way!

Keep up the great work!
 

tarnyloo73

Active Member
One thing I've always wondered was whether there was any basis for the inside the mouth membrane at the back of the mouth, instead of just having the lip continue up and close that section as seen in mammals? So basically not have the dip in at the back of the mouth, but have the skin close things up outside the bone.
More than just a connecting membrane it's the fleshy surround for the large jaw closing muscles at the position where they pass between upper and lower jaw. The feature can be seen in both crocodilian and bird mouths. Simplified diagram, apologies to expert anatomists-

rex_jaw_muscle_diagram_by_strick67-dcijzdp.jpg


Of course we can't be exact about how these animals were built but it seems some elastic tissue is required to cover this area. I think it's a good reason why this is a popular way to depict theropod mouths.

Just as a side note, your sculpt kinda reminded me of the following one from the Trey the Explainer video *Did T-Rex really have bad eyesight?*. I always liked that one. :)
Seen it elsewhere, good model. Can't remember who the sculptor is but I think he/she is well known for museum work.
 

tarnyloo73

Active Member
This is coming along really well! I love all the research and thought that went into this project. I learn more about dinos every time I check this thread.
Very glad you're getting something out of this. I'm a dino-nerd and enthusiastic artist really so please don't think I'm an absolute authority.

When you mentioned booleans it reminded me of when I was first learning to model in 1997. I used multiple booleans to attach parts of my first digital character together (a bad idea, but my modeling teacher didn't know much). Anyway, back then if you clicked boolean, you just got up and left the computer while it "thought" for 20-40 minutes and decided if it was going to work or crash the program (3DS Max 1.2). Booleans were successful maybe half the time at best for me, mostly Max crashed and I lost an hour.
Yep, been there myself (with lightwave3D's booleans mostly), still shudder thinking about it. :D
 

tarnyloo73

Active Member
Been neglecting the 3D modelling this week 'cause I've been painting 3D prints. Got back to the non-lipped version this afternoon and I've got the detail to a point I'm OK with.

non_lipped_detailed01_by_strick67-dcik4d5.jpg


I've given this version crocodylian style cracked facial skin. Not explicitly stated in the Carr et. al. paper but kind of implied as suggested by Mark Witton in his discussion. Anyway this is my take on the 'croc-rex' idea.

non_lipped_detailed02_by_strick67-dcik4o2.jpg


non_lipped_detailed03_by_strick67-dcik4yo.jpg


The green prongs sticking out of the back of the neck are the cervical ribs from c9.

non_lipped_detailed05_by_strick67-dcik5dz.jpg


non_lipped_detailed04_by_strick67-dcik56r.jpg


Just got some battle damage to add which I'll probably do later today.
 
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