Hello, I am new to Moi 3D, I think it is an incredible software. Can you tell me how to import obj models made previously through a polygonal mesh to moi, I have been reviewing tutorials and there is a plugin called SubD, where can I get it, is it free? Thank you

Hi Avila, usually OBJ files contain polygon mesh data where objects are made up of a bunch of little flat facets.

MoI is not designed to work with that kind of faceted data, MoI is set up to work with CAD surfaces and solids.

So usually it is not very feasible to import OBJ data into MoI, you would want to use a polygon mesh editing program to work with polygon mesh data, not MoI.

If your OBJ file is structured to have Sub-D smoothing applied to it then that is an exception and you can bring in a Sub-D polygon control cage using MoI's built in subd converter which can be found in the UI on the SubD tab on the side pane under SubD > Create > "From file".

It is also possible to convert a non-sub-d OBJ file into wireframe lines which can then be opened with MoI. There is a converter available for that on the wiki page here:
https://moi3d.com/wiki/Resources#Obj23dmWireframe_converter

- Michael

You have a free SUBD prog who is directly connected with moi3D in the 2 ways Import / Export
Bonus it has the same Moi Interface spirit! ;)
https://rocket3f.com

All said above is always true...better to have a quadrangular subdivision...and use OBJ format...

Hello Michael, I already understood what you are explaining to me, actually I come from polygonal modeling, it is just that with NURBS I see some advantages when modeling hard surfaces, since in polygonal modeling you have to be careful with the flow of the mesh to then apply a subdivision algorithm and no strange things appear on our surface, while with NURBS you can subtract, add, objects and then apply a chamfer without any problem that your surface will always be fine. So what this SubD does is like a kind of retopology in the NURBS style of the obj, the advantage I saw is that I can model a slightly more organic surface through a polygonal mesh and then add details to this new NURBS object that SubD creates in Moi , and the truth is that it does it very well, this modeling with NURBS may not serve to deform but for the creation of static objects (of whatever complexity) the truth is that it goes much faster (in some cases) than modeling with mesh. Now if you allow me another beginner question, by default the surfaces in moi are seen as translucent, how can I disable this and see an opaque shadow, I mean if there is any way to toggle this. Thank you so much!!!!!

Options / View / disable Hidden lines ?

Frenchy thank you very much for the information, this workflow between the two software seems very practical, thank you very much!

Ah Ok. Thank you very much!

Hi Avila,

re:
> <...> the advantage I saw is that I can model a slightly more organic surface through a
> polygonal mesh and then add details to this new NURBS object that SubD creates in Moi ,
> and the truth is that it does it very well

Yes for this type of use with creating an organic base shape using SubD in a poly modeling
program you can use the built in SubD converter to bring over your .obj file that has a SubD
control cage in it.

That's on the side pane under SubD tab > Create > "From file".

In the future I want to add in some more SubD tools in MoI but the converter works
now as a bridge for doing a hybrid workflow. The hybrid method is doing organic
shapes in SubD and then applying booleans and construction using 2D profile curves
in MoI to build on top of that organic base shape.

Oh also there are some tips here for people coming from a poly modeling background
on NURBS modeling strategies which is pretty different than poly modeling:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael

I was practicing a bit and well now I ran into this problem, I have finished modeling this practice piece and now I want to add a fillet with the selected lines, the problem is that if I put a value in the radius of 3, the fillet causes an error, and what I don't understand is why with a higher value like 4 or 5 it works fine, even with a lower value like 2 or 2.5 or 1 it works perfectly, the problem is with 3 or 2.9. Even a value of 3.1 works fine. I really don't understand where the error is. I attach images.

Hi Avila, can you please post the .3dm model file with your object in it?

It's difficult to analyze what might be going on from screenshots, with the model file i can zoom in and look at stuff.

Thanks, - Michael

Yes, of course

Hi Avila, the problem is there isn't room to fit a fillet with radius 3 because of the previous fillets.

Observe this area of the model as the fillet grows from radius 2 to 2.5 to 2.9:



Radius 2:


Radius 2.5:


Radius 2:9:


Notice how the side indicated above is getting smaller and smaller? At radius = 3 it will be collapsing in on itself.

So to apply a fillet of radius 3 there, you would need to do it at the same time as the other pieces that also had radius 3, that will allow the filleter to make a corner juncture patch in that spot instead of trying to build a fillet along the other previous fillet's edge.

On areas where fillets will collide into each other it's best to put all fillets of the same radius at the same time and in general put largest fillets on first and smaller ones after.

So because of the previous fillet geometry that the new fillet will need to cross over you will need to use a radius of less than 3 there so it can fit around the tight corners that are now there from the previous fillet.

Hope that makes sense.

- Michael

If I understood correctly, I should have planned better, not applied the fillet to the details around the cylinder before I made the cut I did. I understand that a value that is close to 3 causes the lines to cross and cause an error, what I do not understand is why with a higher value it does not happen, at a greater radius these lines should cross each other, in the end I leave it with a 3.1 radius after all this was just practice. Thank you very much Michael

Hi Avila,

re:
> If I understood correctly, I should have planned better, not applied the fillet to the details
> around the cylinder before I made the cut I did.

Correct, not if the cut is going through existing fillets and you want to apply a new fillet of the same radius that will now need to cross over the previous fillets.

Generally it's better to apply fillets when you're finished with cuts.


> , what I do not understand is why with a higher value it does not happen, at a greater radius
> these lines should cross each other,

Just luck I guess. There are some cases where the filleter is able to detect bunching and slice out the bunched area and sometimes the bunching may be small enough that it doesn't prevent trimming of the object.

- Michael

Thank you very much michael, I have been practicing and I realized that you have to plan the creation of the object so that when applying chamfer the lines do not overlap, although in polygonal modeling you have to plan the direction of the polygons to have a correct flow to When applying the subdivision, in NURBS I have realized that it is not modeling for modeling either. Now I had this problem and I don't know how to solve it, I have this line and those two vertices are separated, logically when I extrude it doesn't create a volume since the shape is open, how can I weld those two vertices so that they collapse in their center and solder?, Thank you and sorry for bothering you so much.

Hi Avila, can you please post the .3dm model file in it with the vertices that you want to reposition?

The most general way would be to select one vertex, then use the Transform > Move command, click on the selected vertex as the base point for the move, and then click on the other point as the target point for the move.

Depending on how the points are configured like if they are from the same curve or different curves there may be other shortcuts like drag one vertex to the other or squish them together using the edit frame corner scaling handles.

- Michael

Hello, if I understood, select the two vertices and with the scale tool they glued them in their center, now as one in a single vertex because right now it is only one on top of the other and the shape is still open?

Hi Avila, it would be easiest to help you if you could post a .3dm model file with the objects in it that you were showing.

It's difficult to understand exactly what is going on just from viewing a screenshot or a written description.

- Michael

Hello, so I have this open form, I select these two vertices and join them together by scaling them, ok now how do I add them so that they are one vertex not two.

This is the shape