On 7/29/2026 12:57 PM, Jean-Pierre Delange via ntg-context wrote:
Hi Hans,
I installed the new ConTeXt LMTX version in a separate Windows
directory, so as not to interfere with my existing installation:
> ...
>
I then copied |luametafun-threed.tex| to a separate test directory and
compiled it with:
|context luametafun-threed.tex |
The compilation completed successfully and produced a 15-page PDF. The
3D examples that were rendered — including the Menger sponge and the
parametric and postprocessed spheres — look very good.
The final statistics were:
|MetaPost: 3.051 seconds Total ConTeXt runtime: 3.760 seconds 15
processed and shipped pages Lua memory: 169 MB used, 173 MB maximum |
Some individual figures were also quite fast:
a few have cache = true set, so that helps
|Menger sponge: 2,400 triangles rendering time: 0.612 seconds Parametric
sphere: 20,000 triangles rendering time: about 0.145–0.149 seconds |
on the average parametrics plot are fast (could be sped up if really
needed) but implcits are more expsnsive as there we generate 8 samples
per cube around points
The log also reports substantial temporary memory clean-ups, for example
about 160 MB for the Menger sponge and about 412 MB for the parametric
spheres. The more complex implicit/intersection example reaches roughly
1 GB of temporary data, as described in the manual. Nevertheless, the
complete document compiled quickly on this machine.
I noticed three minor issues:
indeed, we operate on a sometimes 2500 x 2500 bit map, with zbuffering
that can go deep (esp with transparency enabled) with high res color
(doubles), normal vectors etc, and that all comes at a price; if really
needed we can compile with floats which saves a bit; the super sampling
of (here 2) quadruples it;
however, the mesh is the same;
Here's a test:
\nologbuffering
\startMPpage
lmt_scene_start [
width = 10cm,
resolution = 150,
supersample = 2,
crop = true,
projection = "perspective",
eye = "auto", % (-8,32,0),
fov = 80,
light = (0,-1,-2),
intensity = 1.1,
cache = true,
name = "example",
] ;
lmt_scene_material [
name = "surface",
diffuse = (.9,.2,.2),
specular = (.5,.5,.5),
shininess = 25,
opacity = 1,
ambient = .25,
] ;
lmt_scene_implicit [
id = "gyroid",
material = "surface",
code = "sin(x)*cos(y) + sin(y)*cos(z) + sin(z)*cos(x)",
dfdx = "cos(x)*cos(y) - sin(z)*sin(x)",
dfdy = "cos(y)*cos(z) - sin(x)*sin(y)",
dfdz = "cos(z)*cos(x) - sin(y)*sin(z)",
xmin = -2pi,
xmax = 2pi,
ymin = -2pi,
ymax = 2pi,
zmin = -2pi,
zmax = 2pi,
% xmin = -pi,
% xmax = pi,
% ymin = -pi,
% ymax = pi,
% zmin = -pi,
% zmax = pi,
nx = 150,
ny = 150,
nz = 150,
normal = "smooth",
] ;
lmt_scene_render ;
lmt_scene_stop ;
\stopMPpage
This takes 14 seconds runtime here but as we cache only .45 seconds
after that. It's kind of hard to predict at my end what a modern machine
with more cpu cache would need.
1.
At the beginning of the run, ConTeXt reports:
|modules > '3d' is not found |
ok, we can remove the module line (we tested with a module first as that
was easier before integration)
and the final statistics mention one missing module, |*-3d|. However,
the internal 3D LuaMetaFun support is loaded correctly through |mlib-
thr.lmt|, and this does not prevent the document from compiling.
2. One internal reference remains unresolved:
|fig:threed:process:3 |
which appears as “Figure ??” in the PDF.
thanks, fixed
3.
Near the end of the compilation, the log reports:
|luatex warning > mplib: run script: cannot open : Invalid argument |
you probably miss the stl file
I had copied only |luametafun-threed.tex| to the test directory, so I
suspect that the final STL example could not find |luametafun-threed-
sphere.stl|. The PDF was still produced, but the last STL figure was not
rendered correctly. I will repeat the test after copying the
accompanying STL file as well.
As a first impression, the rendering performance on this Windows machine
is very good, and the visual quality of the generated bytemaps is excellent.
yes, and the alternative, vector based meshing not only bloats a pdf,
but us also much more heavy on the viewer (stalls in the worst case) and
is also less reliable
I am now preparing the same separate installation and test under WSL and
native Ubuntu, so that I can compare the three environments on the same
hardware.
Good. Thanks,
Hans
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
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