So, I wrote some code using Buck’s recursive backtracking algorithm, converted the maze into a triangular mesh, and printed this little thing on a MakerBot Replicator 2X:

This all happened back in 2014. I never got around to documenting it. Now that the world is stopped, I’ve been feeling nostalgic.

My conclusion was that gouging out someone’s eyes and putting them in a maze would be up there on the torture spectrum. To solve this, I usually cheat by holding the maze up to the light so I can see where the ball is.

As part of this project, we’re both trying to grow our 3D modeling skills. To that end, I modeled a husky with few polygons:

I followed along this YouTube video, running at 0.25x speed, with many stops and starts.

I must have missed something in the video, however. The narrator essentially UV mapped the barrel twice. The first time he mapped one plank to the wood texture. This gave the barrel its base albedo. It didn’t look natural, however, because all the other planks were generated by an array modifier and were identically textured.

To break up the monotony, he applied the array modifier to realize each individual plank. He then mapped them one by one to the wood texture. But he used this second mapping only to selectively paint on some variety with projective painting. Wouldn’t it make more sense to just map the individual planks to different texels right off the bat to get varying albedo?

This is his T-pose.

I printed four half-cylinders for the axles (halved so I had a flat surface for their foundation) and four wheels with holes slightly bigger than their axles on their inner side. With just a bit of superglue, all the pieces came together.

When one has glow-in-the-dark filament, it’s hard not to print with it:

It bounces in funny ways to help you train your hand-eye coordination.

We decided to make our own using the new mesh intersection operator in Madeup. A reaction ball is the union of one big sphere and six smaller ones along the cardinal axes. Thanks to libigl, I didn’t have to do any cleanup of the result before we printed it:

It doesn’t bounce like the original, but it gets its reaction when you turn off the lights:

I implemented Dixon’s algorithm in Madeup and revolved the curve to lay a solid egg:

My 3D printer only lays half-eggs at a time, but a little glue can put them back together:

The Madeup source that produced this egg took a long time to get right. I didn’t have any arrays or vector functions builtin when I started.

/usr/lib/ruby/vendor_ruby/rubygems/dependency.rb:315:in `to_specs': Could not find 'coderay' (>= 0) among 94 total gem(s) (Gem::MissingSpecError)
Checked in 'GEM_PATH=/var/www/.local/share/gem/ruby/3.2.0:/var/lib/gems/3.2.0:/usr/local/lib/ruby/gems/3.2.0:/usr/lib/ruby/gems/3.2.0:/usr/lib/x86_64-linux-gnu/ruby/gems/3.2.0:/usr/share/rubygems-integration/3.2.0:/usr/share/rubygems-integration/all:/usr/lib/x86_64-linux-gnu/rubygems-integration/3.2.0:/home/johnch/.gems' , execute `gem env` for more information
	from /usr/lib/ruby/vendor_ruby/rubygems/dependency.rb:327:in `to_spec'
	from /usr/lib/ruby/vendor_ruby/rubygems/core_ext/kernel_gem.rb:57:in `gem'
	from ./coderay:24:in `
'

For Christmas, my children received a Printrbot Play. We didn’t have time to get it set up on Christmas Day, as we were traveling to see family. On the road, however, my seven-year-old son and I modeled a turtle in Blender. We took a picture of this turtle eraser to guide our work:

In Blender, we placed this image as a background and traced a Bezier curve around it. My son and I had a serious discussion about tangent lines and continuity. By the end, he was telling me which control points needed to be free and which needed to be continuous.

We extruded the curve and added some bumps on the shell.

Back home, we printed three of these turtles:

Two of them were printed with glow-in-the-dark filament:

This was my first real experience printing with PLA. All my previous printing has been done with ABS, which requires a heated bed to delay cooling of the bottom layers. Heating the bed is really slow. PLA turtles are much faster than ABS ones.