A Little Relief

floral

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Last week I came downstairs to find the elder Zhengspawn had gotten into my box of acrylics and was busily painting one of the myriad bloxen that lurk in the crevices of Casa de Zheng. The original was printed in clear PLA on my Printrbot Simple; I think this is a nice improvement.

painted

I thought it’d be fun to give her paint job a little relief and re-release it as a new bloxen.

The first step in the process is getting the real-world paint onto the 3d model. The easiest way I can think of to do this is to photograph the painted block and then texture map the model.

It occurs to me that I could also have used Autodesk’s 123dCatch to capture the surface of the bloxen, but Lao Zheng is old school, or what passes for old school in the 3d modeling world, and dislikes giving tessellation tasks over to the Cloud.

So photographs it is, just five of them since I’m not doing anything to the bottom of the model; one snapshot for each of the four sides, and one photograph for the top.

Next, I’ll take a basic bloxen and set up a UV map.

UV coordinates on a polygonal model are roughly analogous to latitude and longitude on a globe; they tell the paint where to go on the model’s surface. The first step in assigning UV’s is to unwrap the model’s surface and lay it out on a grid. There are automated processes for this in many applications, but with a model this simple it’s probably easiest and most intuitive to do it by hand.

block uv

And here’s the bloxen with a loose texture map on it. I’m not going to worry about the underside of the model for this project because ultimately it’s destined for 3d printing and the bottom needs to be smooth so it’ll stick to the print bed. Some of my textures are out of focus and distorted and I didn’t bother to texture the sides of the tenons, but I’m just using the painting as a rough guide anyway.

bloxen textured

You can download the UV’d model if you’d like to mess around with it yourself. Converting to STL wipes out UVs so the model’s in OBJ format. Enjoy.

The next step is to subdivide the mesh many, many times so that Maya’s paintbrush tools have some vertices to work with.

subdivided

Most of the setup is done and now there’s a fun few minutes of using Maya’s Sculpt Geometry tool to bump out the vines. (Flowers will come later)

unforeseen problem After a bit of painting I find some WTFfery going on amidships, so this requires a step away from creativity and into the realm of Just Fixing Things. It looks like there is a line of extra small polygons in there, probably created by the subdividing script I’m using. They’ve gotta go, and sometimes the best way to fix things is to Just Delete Them.

wtf

The process destroys my nice quad-only mesh but I’ve been to enough rodeos to know that this probably isn’t going to sink the model later. Moving on, I make a bunch of little flowers, rotate them randomly, and stick them onto the surface of the bloxen.

add flowers

The flowers are very simple models so booleaning them to the bloxen is easy, except for the one flower that rounds a top corner. This one needs to be bent a little bit before it can be added.

deform flower

After adding the mortises on the bottom of the bloxen, merging all the stray vertices, and checking the model in netFabb to make sure it’s manifold it goes to print. No problems whatsoever, which is strangely disappointing since my 3dprinting failures Pinterest board hasn’t been updated in a while.

Ever since I replaced my delrin plungers with an extruder upgrade and switched to a BB ball-bearing based filament spool my MakerBot’s been rock solid.

This little project got me thinking in new directions, so #staytuned for an update sometime in the next few weeks.

4 thoughts on “A Little Relief

  1. Eric

    Hay that’s an awesome block, by the way, my printrbot simple is printing slanted prints on the Y axis, have you ever run into this problem? beings as you’ve printed what appears to be several pounds of filament through your simple. any hints or tips or tricks you can share after all your experience? my email is e.manion009 at gmail, if you can spare a moment for a stranded hobbyist, and help me get my printer printing awesome 3d objects (i really want to print out the penny Balista and attach it to a 3d printed planetary gear set up with a tiny hand crank so i can change the vertical and horizontal planes to dial in the carnage 🙂 Ps. thanks for all the work on Seej!

    Reply
    1. zheng3 Post author

      Hi Eric! Check your gmail, I sent you a message. My experience is that slanted prints on the Simple are due to insufficient tension or slippage in your fishing line.

      Reply
      1. Eric

        yup found it, sorry for the double whammy, i was wondering, after your little one paints the blocks are you going to make some to sell?

        Reply
        1. zheng3 Post author

          I tried doing Etsy for a while but it was just too much hassle. Maybe if I priced them at $100 a pop I could make a tidy profit though.

          Reply

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