I have not wrote blogs for a while, because of various things regarding
to my job. But recently, I started to use
Blender -- the 3D modelling software. And
this is not my first time using Blender, but it is my first time
seriously using it, so I believe that most things I did this time was
new to me.
Blender Foundation, CC BY-SA 4.0, via Blender.org
I am just going to say, Blender is a spectacular piece of software.
While the bad side being that it is too fun to use that I sat in front
of my computer for 2 days straight besides sleeping and eating. Which
made my pinky barely movable.
Installing Blender
Because I am a programmer, and Blender is open source, finally I am
working on Linux. I decided that I would compile blender myself and use
flags like "-O3" and "-march=native" to ensure that I have absolute
maximum performance when running on my host.
First, I downloaded the source code. Blender maintains all its
dependencies independently, which I can just download a pre-compiled
version via "make update" and then uses CMake to configure and build the
project, which had no problem detecting my Nvidia GPU.
After it is done compiling, I had to install it, but Blender does
not follow the program directory structure that Unix uses, but
instead it creates its own independent directory for each version, and
it assumes that you already create an independent directory for it. So,
when I was trying to let it install to /usr/local, it installed itself
to /usr/local/5.2 which is my blender version.
Blender Foundation, CC BY-SA 4.0, via Wikimedia Commons
Therefore, I recommend set the prefix to an independent directory when
installing Blender, like /usr/local/blender. Within the Blender
installation directory, the executable is directly on the top-level
directory, and there is no "bin" folder, so it is better for me at least
to symlink the executables to /usr/local/bin so I won't have to add any
more things to PATH.
Overall, I think this is very good, as I did not see any weird
errors when building, and I don't have to deal with shared library
versions and other annoying things.
Create a Model
Now I can finally start modeling, I decided to make an airplane, or an
Airbus A350-900 to be exact, as it is a childhood dream to create a
model of this plane.
How To Make a Model?
But I have absolutely no idea on how I am supposed to do this, as I had
never done it before. And I end up learning it the hard way to do it.
Since there is a thing called AI, I completely forgot that YouTube
tutorials exist, so I just started to ask AI on how should I do it.
Which it did gave me a few steps to make a model, which I think is
reasonable:
Download a blueprint and import it into Blender
Structure the plane by tracing the blueprint
Create details like windows and doors
Add colour via the "material" section
Importing a Blueprint
Airbus was nice enough to provide blueprints for all their planes like
the A350 and A320, which you can find on the official Airbus
website
for free.
But there is a minor problem, because Airbus uses AutoCAD for their
blueprint drawings and the blueprint is only available in a DWG file. I
know Blender has extensions that allows you to import DXF files (the
open source variant of DWG), but I still had to convert it.
I tried 3 options, for converting a DWG to a DXF -- FreeCAD, CloudConvert and LibreDWG, and I will be
talking about how all 3 options failed for me.
CloudConvert
CloudConvert was the first option I tried as it is the easiest, while
CloudConvert did gave me a "converted" DXF file, the size is very
small, which already raised my suspicion of it not working correctly,
and when I imported it into Blender, the only thing that showed up was
"cargo_door_0".
LibreDWG
Rodrigo Rodrigues da Silva, Felipe Correa da Silva Sanches (São Paulo, Brazil), GNU LibreDWG development team (Free Software Foundation), CC BY-SA 3.0, via Wikimedia Commons
LibreDWG is developed by GNU to serve as a DWG to DXF or SVG converter
(according to my knowledge), and it is a surprisingly very active
project, which gave me some hope of it working.
Installation is very easy, I just used my Linux distribution's package
manager (APT in my case) to install it, but when I run the command
"dwg2dxf" it gave me the same file size, and it is also broken when I
load it inside Blender.
Question: I suspect that CloudConvert also uses LibreDWG to convert
these? I do not know, if someone knows please reply in comments or email
me.
I also tried to use "dwg2svg" which supposably would converts a DWG to
SVG curves, which Blender also supports. But guess what, it gave me
5 lines of SVG, literally 5 lines for an entire aircraft. Which
obviously did not work
FreeCAD
This is the final option I found, which is use a 3^rd^ party software
that acts as an intermediate layer which does the conversion between a
DWG and whatever format FreeCAD supports. But when I try to run FreeCAD
and create any empty project or import a DWG file, FreeCAD just crashes,
so it is really not any option.
What did work
For this, I found a solution purely by accident. I tried CloudConvert
another time, but this time instead of making a DWG into a DXF, I let it
convert from a DWG to SVG vectors, which finally gave me a reasonable
file size, and when imported into Blender, it does indeed work.
The Stupid Single Thread Calculation
Now I have the blueprint imported, Blender became very slow, because
there are a million curves on the blueprint, so I wanted to convert the
curves into meshes, and join all meshes together into 1 mesh.
This is easy, just select all the lines, then right click and select
"convert to" and then select "mesh", then after that select all the
meshes and do shift-J in object mode. But what surprised me is the speed
of Blender -- slower than a turtle.
As you know, I have a Nvidia GPU, but when Blender is trying to convert
curves into meshes, it could only use the CPU to do that, and it is
single threaded. I found this out because since I had a million
lines, when I click convert, Blender stopped responding immediately.
So naturally, I opened nvtop, which is the activity monitor for Nvidia
GPUs on Linux, but I do not see the GPU being used to an extent that
Blender will stop responding. It is only when I opened htop where I see
that a single Blender background worker is using a single thread on my
CPU calculating the millions of curves into meshes.
I end up waiting 10 minutes for Blender to convert the curves into
meshes, and after that I checked the settings, and it is set so that
Blender will use my GPU, but somehow it is not. Then I let Blender merge
all meshes into 1, which also took another 5 minutes.
Modelling Is Actually the Easiest
Finally, I can start modelling, and this is actually the easiest part.
You just create cylinders for each part of the plane, and extrude them
to make it into the shapes of an airplane. The details were also easy
for me to make because I can just edit each vertices.
The vertices system is also what I like about Blender the most, where
Blender only provide a few pre-made shapes, and you have to create
vertices on those shapes to make what you want, which gave you absolute
freedom of what you can do here.
The UI layout is also something I very like, because it minimises
"icons" and write everything in text, so even if I don't know anything
about the buttons I still know what it does, and I don't have to hover
over the icon to see the tool tip text.
By Vincent Yang (me)
Conclusion
This blog is long, but what I want to say is that every piece of
software has its pros and cons, and it is purely on yours perspective
and your use case of determining if a piece of software is good or bad
to you.
In this Blender scenario, if you are a person that just wants to do some
3D modelling and animations, I think Blender is an excellent choice for
you because it has high compatibility, it is fully free as free software
and it is lighter that other options with a size of only 1GB.
But if you are working with other people using other software, Blender
may be an issue for you on converting between file formats, and in my
knowledge, Blender is very different than Fusion or SketchUp.
If this blog is interesting to you, you may go to my blog site to read more blogs like this. Or you can download the Blender model made by me on my website.
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