Hi everyone,

I had a question. I'm waiting for v4 to come out and I read the forum for fun. It's a great place to learn things. I've been wanting to switch from decades of Rhino use. I've grown tired of various things with Rhino and the way they run the company. In any event, I've noticed MoI is missing some key things that I would need.

- Import stl
- Display mass properties and cg of solids, inertias etc
- Dimensioning (but that is coming to MoI)
- Zebra plots would be useful to me
- Also people seem to complain about filleting. But I don't think that will be an issue for me as I can get Rhino to fillet most of the time

So I've been looking around to see what is out there that could fill the gaps. I stumbled across this and wondered if anyone has used it.

https://mecsoft.com/visualcad/

There aren't many YouTube videos I can find about it. But the few I have seen seem pretty cool. I was wondering if anyone has used this and if they think it could be a good companion.

I demoed MoI way back at v2 and liked it. But ended up sticking with Rhino due to the missing features of MoI. But at this point, I don't even care I just want to stop having to use Rhino.

Thanks,

Anthony

Also if you know of any free or low cost software that could do what I want I'd love to know. I'm already aware of ViaCad as Michael has mentioned it many times. But the user interface is so terrible I just can't willingly do that to myself. I'm tired of being tortured by crappy lazy design. That's the best thing about MoI to me is the awesome design, the forum, and the support by Michael. He isn't content to just release crap like everyone else seems to be.

Hi Anthony, well Rhino is probably the best fit for the things you are describing.

You might take a look at OnShape.

I am not familiar with VisualCAD myself.

- Michael

Import STL doesn't really make sense. Its a poly format that hold the least amount of information possible for 3D printing.

However Max Smirnov wrote a great script for mass calcs.
http://moi.maxsm.net/item/35

Thats one of the items..

unfortunately i only have the option to export stl from fea software. i need that info to rebuild the cad model. it's a hot shape to cold shape transformation. so that the deformed part is the shape you want under load.

i'd much rather have a step file exported from fea but i guess that's too hard for them to do for reasons which you guys touch on in this forum sometimes.

thanks for the link to the script. i will definitely check it out. all i really need is the point locations from the stl too. so it doesn't even have to be a mesh in my case. i just need to know where to move the airfoils to so that i can re-loft the part. oh the joys of life.

i guess i should also add the cg location and inertias are needed for various analysis tasks. one of the things i hate about rhino is there ridiculous reporting of them. they clearly have no idea what they are doing. autodesk inventor was the best i have seen at reporting them and displaying the cg. but that's expensive software. i'm retired now so can't pay an arm and a leg to lease software. especially when that's the only thing i would need from the software.

i had tried autodesk fusion when it came out but really didn't like the interface. i looked at the fact sheet for visualcad and it isn't saying that it reports inertia. it doesn't even seem to loft based on the spec sheet. so it may be too basic of a program, which is why there is no youtube videos about it.

so far maybe viacad is about the only option. i used turbocad ages ago. not really sure if it could do the missing things i would need or not. any suggestions welcome though.

Try meshmixer. Import your stl into MM, then export to obj etc.

Hi Anthony ...
I came from Autocad to Rhino and then discovered MoI3d some time ago. Now I do as much of my work as possible with MoI (it's a joy to work with) and switch to Rhino 5 for dimensions and rendering tools. This combo works well for me. I anticipate that when 'dimensions' are available in MoI that I will not use Rhino much at all and will not upgrade to Rhino 6.
For rendering I use Sim Lab Composer and Octane ... both of which can read .obj files created in MoI3d.
cheers,
eric

thanks eric,

i sense you can feel my pain. i can't wait to switch as well. thanks for the workflow advice. much appreciated. i have an old license of keyshot and that has served me well. i tried simlab composer due to Pilou's posts. it's nice for rendering but doesn't do toon shading. at least the last time i tried it. so i have been sticking with keyshot. but at some point i'll have to find something new i imagine. i can't switch to any gpu based rendering software because i'm on a laptop with amd apu. the toon shading is nice because you can render a frame fast so it makes animations doable for me. but i'm pretty much done having to render anything so i'm not worried about that aspect of things. i was surprised how much of a computer load rendering is. i can do cfd and fea with no problem on the laptop but rendering takes forever. i spent some time with keyshot settings to be able to get a half decent render in a resonable amount of time.

thanks co3darts,

i will look into meshmixer. something that can smooth out an stl file and turn it into a step file might save me a lot of work. i wouldn't have to rebuild the model in cad.

-------------

i had one thought too. the fea software i used to use gave inertial properties. the one i'm using now didn't the last time i checked. but they changed solvers. so i'll look again. i might be able to find them there. the only thing with fea mass properties is they are always a little off due to mesh error. so if i can find them in cad that would be ideal.

meshmixer was interesting. i installed it. i could import the stl and export to obj. so i would be able to import that to moi and use as reference geometry?

Hi Anthony, it depends on the particulars of the file, like is it made up of several hundred thousand little tiny polygons or just a few hundred?

In general objects made up of very high density little tiny facets are not suitable for direct use in CAD. You would need a reverse engineering workflow for something like that. Those are tools such as Geomagic Wrap that fit larger NURBS surfaces to dense triangle mesh data.

- Michael

hi michael,

everything i have done up to now has been small models. i don't forsee ever doing a large model. i mostly just do tests of various blade models. i've started to look at a number of things trying to nail down all the various things someone would want to do with my code. but even still, it would be small models as far as i know.

i haven't done all that many tests because of how time consuming it is. at the moment i only have extremely small stl test case. the actual blade test i did awhile ago i can't seem to find. it probably became outdated with a code change and then i deleted it but not sure. once i get v4 i will try an actual test again. by then hopefully my code will stop changing. never seems to end though.

Hi Anthony,

I had a similar problem dealing with various STL files back when I was making jewellery.
One of the work a rounds was to use 3d-Coat as it will import an STL & convert it into voxels.
Aside from the sculpting elements that I used within 3d-Coat, it also has retopo tools with OBJ export.

https://3dcoat.com/features/

I personally found 3d-Coat's UI easier to use & understand, more so than the UI within Zbrush...
...the 3DC trial was fully workable, allowing for various tests before committing funds...
...the cost of 3DC was quite affordable, just as with MoI.

At that time I was using both Rhino & MoI, because Rhino allowed & worked with both mesh objects & NURBS...
...I'd import the OBJ into Rhino, create some basic NURBS geometry around it, which I'd then simply copy & paste to complete within MoI.
(MoI being far easier to use than doing similar in Rhino)

So given it's been done correctly, you should then be able to utilise the retop OBJ as a basic reference when brought into MoI via Max's script..?
...I can't actually test this for you as I've no longer got a suitable computer to do it on.

HTH, Colin

thanks colin,

don't worry about testing. i was just curious what other software people would recommend. i know viacad and rhino come up a lot. but i don't really like those. i'll check into 3dcoat. thanks for the tip

I second 3DC. It's a great program but has a learning curve and may feel foreign for a while but for import export retopo work it's simple.

hi,

so i looked into options some more and had a question. it looks like the 3d coat retop to the viacad subd to nurbs might be a simple way to get a cold shape fea model back to a nurbs model. so it would go stl to obj to nurbs. but i'm not sure what 3d coat version has the retopo. can you use the cheapest one for 3d printing. or do you need at least the hobby version or higher.

viacad has a lot of powerful features packed into a terrible interface. so i'm not too keen on getting viacad. so i may not even do this. but was curious about 3d coat. i watched some videos about the retopo and i think it would be easy and fast to do. the 3d coat website wasn't helpful in figuring out what each version does though.

note; i just recalled that didn't moi add obj to nurbs? is that going to be a v4 feature. if so then i wouldn't have to suffer with viacad.

Hi Anthony,

re:
> note; i just recalled that didn't moi add obj to nurbs? is that going to be a v4 feature. if so then
> i wouldn't have to suffer with viacad.

There is a new feature for converting a sub-d obj file to NURBS, it's meant for processing a sub-d control cage.

- Michael

Try out instant meshes I use ZBRUSH for this function and must say this for a freebie does a very good job.

https://github.com/wjakob/instant-meshes

thanks for the tip. i'll take a look. the models will be pretty simple wing like shapes. so it's nothing fancy.

michael, if the stl file gets converted to obj. will moi then convert it to nurbs? i thought that's what i was reading on the forum in the past. now it seems like you are saying not to do this. so i'm confused

an earlier post suggested meshmixer. however, i don't see that it really converts the stl to a quad mesh. it will save it as obj but it's still triangles. seems like i need auto retopo? i'm not at all familiar with this stuff. so sorry for the dumb questions

update; instant meshes doesn't import stl files

Hi Anthony,

re:
> michael, if the stl file gets converted to obj. will moi then convert it to nurbs?

Well it will, but it won't work very well because a triangle mesh which is what you have from .stl format is a different kind of polygon structure than one that is set up for sub-d smoothing.

For example, a sub-d control mesh should be formed of nearly all quads and not be very dense.

It's not really just a matter of just converting from one file format to another, the structure of an .stl triangle mesh is not the same thing as a polygon mesh that is set up to do sub-d smoothing.

- Michael

i thought the auto retopo will take the triangles and make a mostly quad mesh. that's what i would bring into moi to turn to nurbs patches.