Using blender to make 3D font thingies to print at Shapeways

Posted in a how-to video here:



0:00 Intro
0:49 Choosing a Font
1:06 Blender the inadequate Intro
2:00 The “Fast” route that doesn’t always work
6:07 “Reliable” way
9:40 Deleting Inner Shells
10:43 Exporting to Shapeways via OBJ – No Texture
12:00 UV Mapping, Texture
15:31 Exporting to Shapeways via X3D – With Texture

Having now finished the video, it occurs to me that using a picture as texture would work very well with cylindrical or spherical mapping.

While in this video I’m focusing on printing at Shapeways, its possible to print at home – just export to STL.  However, Shapeways uses a different process which allows for filler material which makes supports a lot easier for this kind of complexity, compared to the FDM process I would use at home on my Solidoodle.

Video captured using Open Broadcaster Software; edited down using Premiere Pro.

From Photoscan to Shapeways: Process 2/N

TL;DR:  Nice idea, but fail.

Holy crunch this is taking a lot of hands on stuff figuring out what works, and what doesn’t.   I decided to step back and take a look at the strength / weaknesses of everybody and see if I could meta a process out of it.

Program Strengths Weaknesses
Agisoft Photoscan Can fill holes; gets normals correct when filling holes
Can Export and Import .OBJ
Can Export and Import WRL
Unique: can create textures from images
Cannot select only visible surfaces for deletion; has to select hidden as well
Can only close holes; does not always generate manifold
Cannot export STL
Cannot resize
Import object cannot have been moved
Netfabb Great job filling holes
Can detect non manifold
Unique: Very good at making things manifold automatically
Import/Export OBJ, STL, WRL
Can resize
No direct mesh manipulation
Free version cannot remove extra shells
Blender Unique: Can do union operations to add missing chunks together
Can detect non-manifold very well
In depth mesh editing
Can resize
Thin wall detection
Import/Export OBJ, STL, WRL
Can remove extra shells
Fills holes with akward normals
Cannot auto-fix manifold
Deleteing faces causes complex manifold problems which escalate quickly
Windows / etc Can ZIP files heh
Shapeways Import texture with ZIP files
Thin wall detection
Unique: Can print in color!
Cannot directly import multi part objects unless ZIP first
Cannot resize
Thin wall fixes loose texture
Cannot get texture when importing OBJ

Proposed Flow

  • Generate mesh
  • Save as A.obj
  • Use circle and block delete to remove chunks to be replaced in blender
  • Save as B.obj
  • Import B.obj
  • Fill holes / clean up / repair
  • Save C.obj
  • Import A.obj
  • Import C.obj – should be manifold
  • Create additional surfaces D1,D2 etc to union using A for reference
  • Union them with C <– not sure if this will work every time. 
  • If it works, save as F.obj
  • If unioning does not work, then:
    • Import B.obj
    • Prune surfaces D1,D2 etc so that there is no overlap with B
    • Create faces to join B and D1,D2 etc so that a fill holes will do the right thing
    • Save as E.obj
Agisoft (if stuck at E)
  • Load E.obj
  • Fill holes
  • Call this F.obj
  • Load model from F.obj
  • Generate textures
  • Export as G + GT (.obj)
  • Start over
  • Load G + GT (.obj)
  • Relocate, Orient
  • Scale, Apply scale
  • Thin wall detect
  • Save as H  + GT (.X3D)
  • Zip H+GT to HZ
  • Upload HZ
  • Look at thin walls situation -> leave open
  • Fix thin wall situations (and other problems)
  • Save as I + GT (.x3d)
  • Zip I+GT to IZ
  • Replace with IZ
  • Hopefully can print.

Wow, that’s a lot of steps.   No wonder I’m a bit frustrated.  

Update as of 6/1 (3-4 days after writing this): 

I tried it.  Twice.   5 hours later: It’s a fail.     The reason is that:  When I get to step G->H in Blender – when I do any fixes in blender – if those fixes involve cutting away dead faces and closing holes or anything like that – I loose texture.  As I usually have to do this surgery around places where I filled it in during step C+DN, Its all over the model, and It would look ugly.

However, I did learn a bit about fitting NURBS spheres onto human faces.   You go into Alt-Q 4-way view (Top, right, front), and first fit the edge pieces (where the surface comes all the way out to the control point); before going on to the other bits.  In the case of a human head, the anchor points are:  just above the ears, an imaginary line going back from the chin, just under the nose, etc.    This could be its own blog post, but I’d need more practice to verify that it works well every time. 

Next up I’m going to try a much-reduced polygon count – get rid of some of this detail that causes the thin walls.  The idea would be to use color and texture to make it look like the human.

From PhotoScan to Shapeways: 1/N – Using Blender as an intermediary

imageShapeways is one of several print services that offer full color prints – something I cannot afford myself.   However, they do not allow on-site scaling – you have to scale the model yourself.    There are also various cleanup steps that have to happen before shapeways will print your model.  For these I use blender.  (ref: shapeways page on blender editing)

Scaling, then Lighting, then Checking for Problems

Blender does not (by default) understand units of measurement; however during import, shapeways will ask what the unit is.  I go with mm; I want the model to be up to 50mm in size.

imageThe original is starting out at (Dimensions) 0.972 (assumed mm) as its largest dimension.  If I scale it up by 50, I get 31 x 48 x 40 instead.    Then, very important:  apply scale so that the XYZ coordinates are actually changed (some tools, like solidify, work before scaling – used for hollowing out an object).

imageimageSide note if you want to check textures: A this point, the model is a bit dark as the original light is now inside the model, and not quite bright enough.   I usually find and drag the Lamp gand drag it out into the open, and give it a distance for falloff of 3000 and more energy. 

And now the fun part!  Turn on the 3d printing tools (via extensions), and … don’t believe everything.  But do check for minimum wall thickness of 2mm.  and.. imageouch.  A lot of stuff.     Now, Shapeways may not complain about all of this – you are always welcome to upload.  In fact, I’m doing just that, to see what they will come back with.



False End #1Do not export as .OBJ.   Shapeways does not process the .MTL and the .PNG file, and you get no color.  Instead, try .X3D.

If you open the .x3d with a large-text-file editor (like notepad++, or even in blender), you’ll find that it has a reference to a texture file with a different name: 


Be aware of it – zip both the .png and the .x3d file into a .zip file for upload to shapeways.   

After the file uploads and gets processed (30 seconds?), you get this screen:


And if I scroll all the way down, to the interesting stuff – Full Color Sandstone:


First, $23.13 .. OUCH.    Second, Thin walls.  It’s a link.   Follow the link. 


As you can see, this is not the sea of yellow that we saw earlier.   But, it also has this “Fix Thin Walls” button.


Oh my, we gave Dan the pox.  Well, no big deal, lets print that anyway …


But now we have lost color. No deal.  Back to fixing wall thickness in blender (and reducing the size of the model!)