MoI discussion forum
MoI discussion forum

Full Version: Moi3d and 3d scanning

Show messages:  1-4  5-24  25-28

From: ado1
30 May   [#5] In reply to [#1]
I got an old Nextengine laser unit and some geomagic software tied directly to that model a while back and tested it out for a week or two
I only paid a few hundred dollars for the lot but the original full setup bought by universities etc would have been around $30,000, most of it for the geomagic software.
Well I really struggled to make it work and abandoned my efforts after a couple of weeks because I just couldn't make it work for me, and most jobs can be solved with a good set of calipers.
Plus some of the file useage was massive and even my six core computer was taking ages with GM

Anyway. I came back to the STL files with a bit of MOI under my belt and looked at improving scans via MOI and I reckon this is the way to go for us poor people and it's far simpler.

You can use MOI to build the scan into sensible parts, the first part you have to do is the "Origin" part and then you build the other sections around that part to achieve proper squareness in three dimensions

I've done hardly anything on this stuff, it's been a whole new area of learning but the geomagic part for me was abandoned pretty quickly

So my recommendation for a cheapie 3D setup is get a scanner that does good STL files, and use MOI to orientate/Build your result into a full drawing

for stl/stp stuff I used Alibre
https://www.alibre.com/forum/index.php?threads/new-add-on-for-conversion-of-stl-to-stp-and-open-in-alibre-complete-c-rewrite.26312/

my 2cents

Image Attachments:
scan1.jpg  scan2.jpg  scan3.jpg 


From: Michael Gibson
30 May   [#6] In reply to [#5]
Hi ado, the kind of odd looking lumpy shaping comes from using the MOI SubD converter on a mesh that has not been set up for sub-d smoothing.

Here's some examples of how the control mesh should be formed for sub-d smoothing to make a good quality result:
https://www.youtube.com/watch?v=ckOTl2GcS-E

- Michael
From: ado1
31 May   [#7] In reply to [#6]
I have more detailed stuff via a 50MB Alibre Stp

Which converts to a 75MB MOI stp (about 10 mins)
and a 132MB 3dm file (a few minutes)

It's the processing time for these things when you're just experimenting, it starts to get silly pretty quickly

If you're getting money for a job no doubt it's worth more hassle

edit: I've converted the lumpy 20MB to fbx and it's processing back into MOI
So far I've done the washing up and 5% is done. Going to walk the dog now.
MOI is using 14GB of memory in task manager atm

Image Attachments:
scan4.jpg 


From: ado1
31 May   [#8] In reply to [#7]
Nope. it all just blew up/crashed

Did an stl to stp in Alibre 2.5MB to 43MB PRT file (Alibre STP)

saved from Alibre to IGS 137MB
(MOI couldn't open Step Sat files or they took ages)

opened in MOI and saved as a 3DM 287MB

It's a messy subject matter area of work IMO but the ability of MOI to draw inside the scan makes it far more practical

I think my earlier work to get the 20MB file involved mesh reduction in MESHLAB and faffing about with that
MESHLAB is a good program, like MOI it's tightly written and very efficient

edit: I just remembered, if you can get the STL under 1MB then life gets a lot easier.

Image Attachments:
scan5.jpg 


From: Michael Gibson
31 May   [#9] In reply to [#8]
Hi Ado, I'm not surprised there are problems. The MOI Sub-d importer is not intended to be used on high density scan data with hundreds of thousands of triangles. It's designed to process a sub-d control cage made with a few thousand quad faces.

- Michael
From: Frenchy Pilou (PILOU)
31 May   [#10]
You must see to the free 3D Coat Print and its "Voxels" section!

No limitation at the importation!

So you can make your object like you want

Only limitation 40 000 polys at the export

if this is not enough for you as you have a perfect object at the screen!

take some images and you will find some free AI for make some 3D smart models!


From: pafurijaz
31 May   [#11]
There's a way to convert STL files to STEP files easily and on the cheap, but the more complex the file, the bigger the STEP file will be, because it'll be made up of loads of triangles.

So my advice is to use apps like MeshLab, which has a few tools for this kind of thing to reduce mesh complexty, and then bring the file into Blender to further reduce the complexity of the STL mesh.
Blender also has some tools for working with meshes and cutting down the polygon count a bit, like the modifier "Decimate" with this you can reduce the size of the STEP.

Here's how to convert STL models to STEP for free:

Import the into FreeCAD and use FreeCAD's internal procedures to convert the model to a CAD part, under the workbench Part and use the command "Shape from Part"
After that, save the model as a STEP file: that's the quickest way.

This way you'll be able to work in Moi3D using snaps and the geometry from the scanned model, but keep in mind that STL models are meant for 3D printing and usually have a ton of triangles, so the exported STEP file will be really heavy to handle.

Of course there are other methods too, but it all comes down to your experience with both the software and modeling itself.

Converting an STL file to STEP format with FreeCAD sometimes took a while.

So my advice is to use mesh modeling apps like Blender and try to make some elements with SubD, then export the model as OBJ, and then convert it in Moi3D using the SubD command.
But there are many methods, and skills you pick up over time.

Last thing; with FreeCAD, you can import STL models and use them as a reference to create the CAD model directly with its built-in tools.
But as I said, it requires experience and it's not the easiest CAD program to use.
Still, it's useful to have it, because sometimes you run into these issues with Moi3D not supporting meshes.

Below in the image you can see an STL file from a laser scan converted using the method I suggested.

Cheers

STL decimated in Blender


STL exported from Blender and converted with FreeCAD into a part CAD


STEP imported from FreeCAD export


STEP imported from FreeCAD export

Image Attachments:
STL_01.jpg  STL_02.jpg  STL_03.jpg  STL_04.jpg 


From: Michael Gibson
31 May   [#12] In reply to [#11]
Hi pafurijaz,

re:
> This way you'll be able to work in Moi3D using snaps and the geometry from the scanned
> model, but keep in mind that STL models are meant for 3D printing and usually have a ton
> of triangles, so the exported STEP file will be really heavy to handle.

There are more problems with this method than just getting really heavy.

It's just fundamentally not the type of data that CAD programs are designed to work with.

No spheres, cylinders, or actual curved objects of any type, just a big pile of trimmed planes.

Usually it isn't a useful result.

- Michael
From: ado1
31 May   [#13] In reply to [#9]
This saga isn't over for me yet

I tried reduction in Meshlab but it hangs around the 98% point for the obj file

I did get a 7.3GB subD file from the Alibre IGS in MOI exported as an OBJ file, a testament to MOIs stability

Does anyone know of a Utility for turning a polyline DXF into an OBJ file?

Edit: I'm better off turning an STL into an OBJ file aren't I, duh.

Image Attachments:
7.3GB moi subD.jpg 


From: pafurijaz
1 Jun   [#14] In reply to [#12]
Hi Michael, I must have misunderstood what the goal of importing an STL file was, since in the first message was mentioned reverse engineering programs, something that actually comes up in professional work, because laser scan data are point clouds that get turned into polygonal 3D files.

In fact, many professional CAD packages let you import mesh files and then reconstruct them using tools that allow you to build on top of the references.
I often work with this kind of data format myself, STL files, and then do the reconstruction file over 3GB and some files I'm working on are over 2GB STL, and I had to reduce them because the full model is over 50GB of RAW data.

So that’s why I suggested this approach, considering that Moi3D doesn’t have a way to import STL files, except for some JavaScript scripts, and I figured that having a STEP file, even if polygonal, could let you do the reconstruction right inside Moi3D's tools.

Cheers
From: pafurijaz
1 Jun   [#15] In reply to [#13]
Hi ado1, could you share that 3D file? That way I can take a better look and maybe I can get you a usable model for your purpose.

Although at this point I have to admit I might not have understood what you’re aiming for by having an STL model imported into SubD, which isn’t possible because of the triangles.

However, if your goal is to have a SubD model in Moi3D, the best thing you can do is re-topologize using mesh modeling applications like Blender, or buy an add-on for Blender, “Quad Remesher”, which costs just over 100 dollars and does an excellent quad-topology reconstruction of 3D meshes, and that lets you import it into Moi3D.

There are issues using those kinds of models directly, though, because Moi3D can’t recognize the sharp edges of subdivision surfaces, so you could still use Blender and other add-ons that let you export the models to IGES or STEP, which take the sharp edges in SubD models into account.

Quad Remesher link -> https://exoside.com/

For example this model below was done manually by me yesterday for a beginner user, and I "retopologized" the model with Blender from a file STL of a laser scan.

Model exported from Blender 3D as STEP file.


Cheers

Image Attachments:
manual-retop.jpg 


From: Matadem
1 Jun   [#16]
@pafurijaz

end result looks good
From: ado1
1 Jun   [#17] In reply to [#15]
I can supply the original stl the nextengine produced so folk can play with it

knock yourselves out

Whoever can do the smallest good looking nurbs file, for MOI editing/creating a sexy final object, is the goal.

and that means that MOI users can do 3d scanner work on the cheap

Attachments:
compressor part from nextengine.stl


From: ado1
1 Jun   [#18] In reply to [#17]
I can start the ball rolling from my faffing about

107MB subD from an STL reduced to 147KB

Image Attachments:
107MB 147kb part.jpg 


From: pafurijaz
1 Jun   [#19] In reply to [#18]
Hey, I downloaded the STL file and, using Blender with an add-on called “QRemeshify”, I converted it into a quad topology mesh.
Then I exported the model as OBJ and imported it into Moi3D using the SubD command.

I’m attaching the OBJ file below, so you have a model in Moi3D to work on that’s lighter than an STL file.

You can also find QRemeshify on GitHub, but maybe from this link (https://ksami.gumroad.com/l/QRemeshify) you get a version that works with the libraries as well.
However, if you’re dealing with this kind of file, you might want to consider Quad Remesher, which I already mentioned in my previous comment, because it produces a much better remesh.



Cheers

Attachments:
compressor-model-obj.zip

Image Attachments:
quad-remeseh.subd.jpg 


From: Frenchy Pilou (PILOU)
1 Jun   [#20]
From any of your devasted images above you can have that! (Banana)





Rodin or Tripo


Meshy

https://moi3d.com/forum/user.php?webtag=MOI
Krea 2


Here i take only one image (you can take 2 images in Krea)

Finally only Krea gives free models :) (from that i speedy test )

But heavy one and triangulated 100 megas
So must use for example some quads decimater so 1 mega! :)
Here the free Instant Mesh


then in Moi with SUbD from Create file



or Import OBJ t by Max Smirnov then Subd_Beta9 or not

From: pafurijaz
1 Jun   [#21] In reply to [#20]
This is impressive, really.
i can't wait to see the finished model
From: Frenchy Pilou (PILOU)
1 Jun   [#22] In reply to [#21]
I am afraid that is very difficult to have the same result than the first blue image following!
(Best will be to redraw ! :)

You can ehance some regulates inside Instant meshes but...

The Createfrom file will be the better result ... no time now for continue!

Here the SubDBeta9 with small Subd (16 %)



This is just a mirage! :) And a miracle because start image is so devasted! ;)


I am astonished! :) Bon courage for make the same in 3D! Because here it's 10 seconds! :)

From: Michael Gibson
1 Jun   [#23] In reply to [#14]
Hi pafurijaz,

> So that’s why I suggested this approach, considering that Moi3D doesn’t have a way to import
> STL files, except for some JavaScript scripts, and I figured that having a STEP file, even
> if polygonal, could let you do the reconstruction right inside Moi3D's tools.

This is true, but the reconstruction process has a very high learning curve and is better done with tools that are specifically focused on that type of task which MOI is not.

The OP asked:

quote:

scannes items can be exported as stl and obj...so import the obj ...I ll be fine?


The simple answer is "nope, you cannot just open up scan data into MOI and proceed like it was an object you modeled."

- Michael
From: Michael Gibson
1 Jun   [#24] In reply to [#15]
Hi pafurijaz,

re:
> because Moi3D can’t recognize the sharp edges of subdivision surfaces

No, not true - edge creasing and weighting are supported by Moi's subdivision surface converter.

But there is not any way in the .obj format to represent edge creasing, you need to use FBX format for that.

- Michael

Show messages:  1-4  5-24  25-28