Richard Uschold - 2010-08-27

I have a file from SketchUp in .dae format. I used MeshLab to convert it to .stl, .dxf, .ply, or .off.


.dae -> .stl via MeshLab
.stl -> .g via stl-g

The output of stl-g has MISSING faces! I traced one: a VERY THIN face
in the letter "C". facetize actually FIXES this by adding the missing
face, but it is a little tricky! I have to intersect with a box to
remove at least one letter. If the intersection box encompases ALL of
the letters, facetize apparently notices that there is nothing to do
and leaves the original BOT unchanged.

Is there a way to force facetize to actually re-do the triangulation?


.dae -> .dxf via MeshLab
.dxf -> .g via dxf-g

facetize gives the following error:

facetize Gothic-a.f Gothic-a.c

{Gothic-a-bx.s} + {Gothic-a-bx.s}
{GothicDxf-a-zLC.s} + {Gothic-a-bx.s}
EDGE_G_LSEG  a6ddd70 pt:(82.962331 5.061652 1.000000)
       eu uses=12  dir:(-0.011223 6.846189 0.000000)
EDGE_G_LSEG  a6ddc50 pt:(82.973554 -1.784537 1.000000)
       eu uses=12  dir:(0.011223 -6.846189 0.000000)
nmg_2edgeuse_g_coincident() lines colinear, vertex check fails, calling colinear anyway.
nmg_shell_a() at 2549 in nmg_mk.c. Shell has no children

nmg_shell_a

Error: 1WARNING: facetization failed!!!


.dae -> .ply via MeshLab
.ply -> .g via ply-g

facetize gives the following error:

mged> facetize Gothic-A.f Gothic-A.c

{GothicPly-AZuc.s} + {Gothic-A-bx.s}
nmg_region_v_unique():  2 verts are the same, within tolerance
VERTEX  70076f0
   vu_hd  70076f4
9c903c0 vu_hd.forw
a65a520 vu_hd.back
98afde0 vg_p
   VERTEX_G  98afde0 0.000004 -0.000001 0.000000 = XYZ coord
VERTEX  9c92ac0
   vu_hd  9c92ac4
9c936c0 vu_hd.forw
9c92b90 vu_hd.back
9c92bf0 vg_p
   VERTEX_G  9c92bf0 0.000004 -0.000001 0.000000 = XYZ coord

nmg_region_v_unique()

Error: 1WARNING: facetization failed!!!


  off-g has no man page and produces a file with no objects in it, i.e., the ls command produces a null output.


Except for .off, the imported data looked just fine in the mged editor.

I have no idea where the error is: Meshlab export or BrlCad importer, maybe even SketchUp export.

Questions:

1) Do you know of a RELIABLE converter that can use SketchUp output (default or .dae) and generate something that can  be imported into BrlCad?

2) The .stl conversion path almost works and I have fairly simple work around to make it useful. I asked this earlier, but….
     Is there a way to force facetize to actually re-do the triangulation even if it is not strictly required?

Richard