Thx! So seems the best from Moi to SimLab seems OBJ quad + triangles even Step and IGES are transformed by SimLab
Basing on the fact that Moi nurbs transformation is better than Composer! ;)

Hi Pilou, yes OBJ format with "Output: Quads & Triangles" is probably the best transfer format.

- Michael

I started off using .obj but now use .3ds. (in SimLab Composer Mechanical 6.18)
But only because 3ds gives me the correct orientation with the default import setting in SimLab.
Oh and I have to change my preferences in Moi from millimetres to metres prior to export.

Mike.

Hi Mike, usually you would only want to use .3ds format as an absolute last resort - it's a very old format and has a major limitation in that it has no way to store vertex normal shading information along with the mesh. When that shading information is missing, it means the rendering program has to create it by averaging the normals from the polygon faces and that usually leaves some hint of the polygonal structure in the shading. When the renderer is able to use the vertex normals from the original NURBS surfaces which are in the .obj file that makes the shading look exactly the same as the original surface and totally glitch free.

By orientation do you mean your objects are being rotated when imported into Simlab using .obj format?

If so then you should be able to fix that by using the option in MoI to change the orientation used for generating .obj files - it's a setting under Options > Import/Export > "OBJ options" > Orientation . Change the dropdown there from "Y-Up" to "Z-Up" and that should solve that.

- Michael

Thank you, Michael, I will certainly follow your advice.

Mike.

OK !
All works fine!
The cool thing is that all names' objects and work's colors are conserved!
after apply some materials :)

Michael, I've gone back to 3ds having tried obj and run into problems that I couldn't solve.
My interest and use of SimLab Composer is for the simulation of mechanisms designed in Moi for 3D printing.
At the very beginning of my use of SimLab I imported .obj files but had difficulties that I couldn't resolve and didn't know whether it was my incompetence with SimLab, errors in my (Moi) design or what. In desperation I tried another file format and chose 3ds, for no particular reason.
Problems eased and I managed to produce several satisfactory simulations.
I'm inclining towards doing 2 simulations per mechanism. One early on in the design as a 'proof of concept' and one at the end of the design to pick up the (all too many) errors that I've made.
On my latest project I'd done the 'proof of concept' simulation shown in the attached 3D pdf.
Then, during the course of the design I received your recommendation to use obj format - for better render performance.
So back to obj having by that time largely forgotten my initial struggles with it in SimlLab and I just couldn't get the simulation of the final mechanism to work. Eventually I realised that I'd used 3ds files for the concept and was now struggling with obj files.
Back to 3ds files and happiness.
I've sought comment from SimLab and their recommendations regarding the best file types to import for simulation and though that I should post here to for your comments and for the information of others following a similar path.

Mike.

Just received this advice from SimLab:
"For simulation it is better to use an nurb based format like ACIS or STEP
while OBJ and 3DS will bring better material appearance.

ACIS and STEP will include inertia information, to get more accurate results.

So my suggestion to you is to try ACIS and STEP from MOI for simulation."

Hi Mike, when you exported the OBJ file what setting did you use for the "Output" option, this one here:




If that is set to "Output: N-gons", then that's probably what's causing your problems, if you change it to "Output: Quads & Triangles" instead that may solve your problem.

If .3ds works good enough for you and gets the job done then well certainly use it - but also with .3ds it will be easier to run into some shading quality problems with it as well.

- Michael

Seems your objects of the PDF 3D animation are "broken" ? (top horizontal bar volume)

What special parameters input (or not) in Simlab for have PDF 3D animation?

By no planning on my part, it is set to Quads and Triangles.

the pdf animation looks OK to me so I am not sure what you think is wrong.

I'm as far from an expert as one can be so my stab at an answer to your question about 'special parameters' is that the 3D animation is part of having the 'Mechanical' version of SimLab Composer.

I have that at the start of the 3D PDF video!
Does this normal ?

Hi Mike,

> By no planning on my part, it is set to Quads and Triangles.

Hmmm, well it sounds like you had the settings all set up properly.

If you run into problems with .3ds in the future let me know and we can try to figure out why .obj format was causing problems for you - .obj format works for many others exporting into SimLab so it should be possible to avoid whatever problems you were running into, I would probably need to see more details on the problems in order to give you any more tips though.

- Michael

No, it does not.
Each moving part should be a different colour.
And, at the start of the video, the lever at left should be approximately vertical.
I'm viewing the pdf using the latest version of Adobe Acrobat Reader DC.

Michael, perhaps you missed this edit to my previous post:

Just received this advice from SimLab:
"For simulation it is better to use an nurb based format like ACIS or STEP
while OBJ and 3DS will bring better material appearance.

ACIS and STEP will include inertia information, to get more accurate results.

So my suggestion to you is to try ACIS and STEP from MOI for simulation."
EDITED: 15 Feb by MGG942


So for simulation (and simple rendering) I've switched to STEP format and that seems fine for simulation and the level of rendering that I want.

Mike.

Hi Mike, yeah sorry I missed that part, that's great that STEP format will work for you.

- Michael

Frenchy, I've completed the design of this mechanism for 3D printing. Simulated it in SimLab Composer Mechanical and made a video that shows what the mechanism looks like in action.
The big plus of the 3D pdf file is that one can rotate the view in any way you want to.
Anyway, here is the YouTube link: https://youtu.be/cHt5Pa25lRg

Very nice!

So your objects were not broken! Only in the dark for me! :)


In your animation Simlab blends Physics and curves path objects or it's only "physics"?

PS In the PDF 3D for mysterious reasons I must click one by one object for have only one object colorized!
It's the same for you? (have you a Pc or a MAC ?)

I think that the simulation is a blend of physics and paths.
For example the part that is moved 'horizontally' is moved by physics but it has a constraint put on it so that it can only move in a straight line.
The constraint is necessary because I haven't included the base as an active part of the simulation.
The part that is moved vertically and one can see wobbling is physics only. It is restrained by interaction with the part within which it slides. And I have to give quite a bit of clearance at the design stage to cope with the inaccuracies of the 3D printing process that I'm using.
The gears and other rotating parts are constrained to rotate around a fixed axis.

As for the pdf.
I'm using Windows 10 64 bit.
The pdf does do something odd with the colours so that they are sometime quite different from the videos but for me they are always coloured and do not need to clicked on.

I planned to attach a pdf of the final design to see if that worked better for you but it's 24Mb so I've attached a pdf of an earlier project which is rendered in wood!

Thanks for the infos!

This last Wood PDF 3D works like a charm with all pieces in different color materials and of course the animation too!

I am right if I say that in this PDF 3D I can't rotate the handle for move the system of gears ?