Updated T. rex skull - W.I.P.

[Dinoreplicas]

Assembled the vertebrae drawings into a cervical sequence. I've basically copied the photographed layout from the Brochu 2003 paper so I think it's pretty complaint with the science. The articulating surfaces of the cervicals are angled so that the neck forms a gentle s-curve. This image will work as a template to place the neck bones against, gonna start them this weekend.

[Dinoreplicas]

It occurred to me I should add the skull to the neck verts image to make a complete bone placing template. Don't know why I didn't think of this in the first place, nevermind it's just a cut and paste job.

You can't see the ball joint (occipital condyle) in the image because the back of the skull obscures it. It fits neatly into the cup of the first cervical (atlas bone) and on a large Tyrannosaurus is about 10cm in diameter. That's about the size of my fist!

Had a few days off the old tyrant, there was some overdue DIY to sort (my excuse anyway). Now I'd like to build some momentum again with the 3D modelling.

[Dinoreplicas]

OK finally got some time to get back to it, this is the bones of the right pes in 4 views. The standard system is to use roman numerals to indicate the digit number so I've done the same, grid lines at 10cm apart as usual.

Checking the Brochu paper confirms that Sue is missing a few toe bones (only the claw of the hallux is present) but these have been studied from other rexes. A lateral view might be overkill as I think I can use the other views to lock in enough of the detail in 3D.

[Dinoreplicas]

Started the 3D work on the neck so I had another thorough study of the cervicals in the Brochu paper and the Sketchfab Trix 3D display to prepare for this. C1 (atlas) is a very individual structure and c2 (axis) is different enough to probably need its own mesh too. C3-c9 however are broadly homologous each one being a variation on the one before.



Should be able to take advantage of this in that I can model an initial vertebrae, then duplicate and modify for the next and so on. So the decision I've made is to start at the mid point (c6) and work both forwards and backwards along the sequence. Working from the middle means I start with an 'average' cervical that will change minimally in each direction.



With complex shapes like cervical vertebrae there's a bit of fiddling required to get a decent low-poly mesh that represents the structure in a broad way but will subdivide fairly evenly for sculpting later.

[Dinoreplicas]

Vertebrae cloning plan checks out so far, c4 and c5 are just modifications of c6 with minimal topology changes.

[Lone Trike]

Your drawings look spot on, as always! I can´t wait to see the final assembly in 3D

[Dinoreplicas]

I can´t wait to see the final assembly in 3D

Me too, the amount of time I've spent on this is getting a bit crazy now, I really want it finished.
I'm just about there with the base meshes for the neck bones, should be done with this part in an hour or so. Going to push to make progress this weekend, get it fitting together then get some detail sculpting started.

Here's a quick lo-res turntable of c1 and c2 in relative position.

[Dinoreplicas]

Just leaves c9 to add which is a fairly simple derivation of c8. No doubt there'll be (hopefully minor) tweaks and adjustments to enable an articulated sequence without intersections in the individual meshes.

[Dinoreplicas]

Cervical ribs complete (will be mirrored horizontally for right side).



Update
Wahey It fits! With only a few minor adjusts, guess that's the benefit of planning. Still a few tweaks here and there but this is just about ready for detailing.

[Mini Minmi]

Beautiful work. It's fascinating seeing the progress and all the work and research involved.

[Lone Trike]

Beautiful work! Everything fits together so nicely.
Just a question out of curiosity! Do you only sell your models via shapeways or would you consider selling just the stl or obj files to customers, who have their own 3d printer at home for example?

[Dinoreplicas]

Beautiful work. It's fascinating seeing the progress and all the work and research involved.

Thanks, I thought the pre-production work got a bit excessive but it's really paying off now I'm modelling.

Do you only sell your models via shapeways or would you consider selling just the stl or obj files to customers, who have their own 3d printer at home for example?

I'm not planning on releasing 3D mesh files (at least not for the dinosaur skull models I've made so far).

[Dinoreplicas]

Had to make a UV map from the low poly 3D skull and neck bones. This always takes ages, really time consuming. It's of no use for the 3D print but will help me when I do some preview renders of the final model.

Basically what I will do is bake the fine bump details into an image texture once the high poly model has been sculpted. This way I can render a medium resolution version of the sculpt and still show fine details. This is necessary as my PC is old and under-powered and would take ages to render the finely sculpted model at the highest level of detail.

[Dinoreplicas]

A quick turntable of the Sub-D mesh - going to start detail sculpting now.

[Dinoreplicas]

Got back to this after another break and I've started blocking in the major forms of the skull. For the detail sculpting nothing suits my workflow better than Blender's multi-resolution modifier. It gives me a few advantages over the other sculpting methods. I'll increase the subdivision when I can't get any more detailed at this level.

Although the cranium and jaw are seperate meshes I work on them together alternating between each part to ensure they fit together correctly. Because of the amount of planning and accuracy in the base meshes this is proving a trouble free process but I still test the fit periodically by rotating the jaw into the closed position.

[Halichoeres]

Sounds like all the prep is paying off! Nice work.

[Dinoreplicas]

Sounds like all the prep is paying off! Nice work.

Thanks. I enjoy the research and production drawings but the process can be quite an uphill slog. Now I'm mostly modelling and referring back to my reference it's (a little bit) more relaxing. Of course preparation gets you maybe 90% of the way at best and when I'm elbow deep in the 3D space I find there's still a few things to work out on the fly.

[Dinoreplicas]

Introducing high-level details now that the mid-level forms are defined. There's no point into going into too fine detail as it won't register well in the 3D print.

In a similar vein I've cut the sutures (seams between the bones) quite broad and deep so they will show clearly in the final model. I'm learning got to keep this sort of thing in mind when working for scale reduction.





The weird bright green is just to help me gauge the forms in 3D. For sculpting detail I find it useful to have a broad specular highlight that is shifted chromatically from the diffuse colour. In addition to the green with yellow highlight I often use blue/cyan and red/orange. Don't know if anyone else does this but it works for me.

[Dinoreplicas]

This dorsal view shows the latest parts I worked on at the back of the head. Pretty much done on the cranium now, Probably need a final pass after the jaw is done, maybe a few adjusts in he joint area.



I'm now getting down some of the very tyrannosaurian features I wanted this model to show.

• The relatively narrow snout with the back of the nasal tightly pinched between the lacrimals.
• The broad back of the head and the huge spaces for the jaw closing muscles
• The bony bosses at the top of the postobitals and the rough pitted texture on the nasal.

[Dinoreplicas]

The detail sculpting for the lower jaw happened fairly quickly, It's a lot simpler part than the skull with much less interior surfaces.