Easter Traditions: the Dinobunny (and Sculpting 101)

My girlfriend likes dinosaurs. We have a wacky, inflatable dinosaur that's about two-and-a-half feet nose-to-tail, that got paper-crafted bunny ears at some point. I'll also state this post will feel very dated, as my sculpting abilities progress.

The Great Dinobunny. Every year, he'd hide plastic eggs around the apartment, containing a variety of objects. Some years it was candy, sometimes little dinosaurs or other toys. This year, I printed some eggs (we moved 4 months ago, not sure where things are), and the avatar of the Great Dinobunny.

Avatar of the Great Dinobunny

The project started with the 13 eggs from this design on Thingiverse.  They're a lovely design, printed well 95% of the time, a little longer/thinner than previous eggs - fine for the purposes.

Next, was the 3D Bunny Puzzle by Sakati, also on Thingiverse. As it's a No Derivatives license, I'm not posting the Dinobunny .stl back out there. The 12-piece puzzle is based on the Stanford Bunny, basically a project in 1994 where they tried to 3D model a bunny as accurately as possible for a computer to display. You can read more about it on Wikipedia in this article. I ended up making the dinobunny 13 pieces — I wanted the ear puzzle-piece to be printed white, with the rest of the dinobunny being green.

I printed the puzzle at 50% size, and it was nice. The tolerances were good; not too big, not too little. But for a dinobunny, I needed to do something more. Imported the puzzle into Blender - all of the pieces were imported into their proper space...no dragging needed!

Version 1: Crossbreed

Fixed up the head and the tail - tail was still rough

I haven't done a lot of sculpting in Blender 2.8. Blender 2.79 and lower, I did sculpt several times, but it was never quite natural for me. Blender 2.8, I used most of the same tools, but it just felt better.

Sculpting Tip #1: Turn on Dynamic Topology, aka Dynotopo

When you're in Sculpt mode, it's in the lower right panel, there's a checkbox labeled "Dyntopo". Click that, and your sculpting will look a lot smoother - at a cost of more polygons being created. Also, I've noticed that Dynotopo becomes unchecked when you leave Sculpting mode, at least in my version of 2.8.

Dynotopology off (turn on!) and Symmetry as Mirror is all unselected

Yeah, when you turn on Dynotopo, this is a junk message. Click "OK" and move on

Sculpting Tip #2: Deselect Mirror under Symmetry

It's in the same panel as Dynotopo - immediately below. It's not so much on/off, as select everything off. In the case of the dinobunny, there wasn't anything to mirror - and leaving Mirror X on (the default) made me question my sanity/sculpting.

Sculpting Tip #3: Be aware of what you're sculpting

I definitely did NOT want to affect the puzzle portion. It meant extra care when I was using sculpting tool near the existing puzzle cut outs and tabs.

The new Dinobunny neck

Stretching the neck out was problematic for me. I basically grabbed a bunch of vertices and dragged them up - but it wasn't on a straight z-axis. The next step was making a cylinder with the height of the new neck, with the diameter of the "post" in the puzzle's neck...this served as a guide on grabbing the vertices to the right place. (I want to say I did smart things, like changing the neck pieces to match the rotation face of the cylinder, so I could just "z-z" and move along the object's own z-axis as opposed to global z-axis. It also works to just join the cylinder and the piece you want to move up/down, and then use "p" in edit mode to separate them again. z-z now works for the piece, using the angle of the cylinder.)

Well, you now have a stretched out neck. It no longer looks natural, just a bunch of flat planes.

Before

After

I spent some late night  hours on this, and no longer entirely sure of the process - it's good to document things as you go, so you can be accurate when describing your descent into madness. Remember: dynotopo ON, symmetry OFF. In sculpting mode, the strength & the size of your brush - they're both impacted by how far in/out you zoom in on the model. A feature, not a bug.

Dynotopo was necessary here — I wanted to get the organic, slightly lumpy roundness bits of the original...and it wouldn't make the new faces I needed if I just tried to dump clay strips down.

I also sculpted with non-active pieces visible, as it gave me feedback on how the rest of the pieces looked with the changes. Sculpt mode doesn't affect those non-active pieces, so it was a safe method.

Brushes used:

• Used Draw more often than Clay Strips, both as a +/- brush.
• Smooth for cleaning things up
• Alternating between Crease and Pinch for better definition of transitions

Making Two Pieces instead of One

As I wanted to make the ear portion white, it meant I had to break apart the back of the head/neck piece. I didn't use any sculpting technique - it was a quick creation of a cylinder and cube merged together, and then using Boolean>Intersect on it to make the bottom part. I briefly scaled it up, to then Boolean>Difference to create the puzzle-fit in the top portion. No sculpting needed!

Remaking the puzzle portion - notice my edges are sharp compared to the original