NVil Forum

General Category => General Discussion => Topic started by: Noobnvil on December 30, 2025, 05:38:02 am

Title: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on December 30, 2025, 05:38:02 am
Hello
I have a project going on in Moi3d.
I want to bring some object into Nvil to make a "shell" around the object and send back to Moi3d.
What is the best format to do this and to import it and back and stay accurate?

Thank you!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: kevjon on December 31, 2025, 05:29:08 am
Set MoI preferences to metres
Export from Moi in obj format.
Set NVil to metres in preferences.
Import obj into NVil using merge scene.

NOTE: Moi is a nurbs modeler (nurb surfaces). Nvil is a mesh modeler (Polygons).

MoI does not support import of mesh data that NVil generates however you can use the SubD function of MoI v4  to import obj format but it will apply a subdvision to the mesh geometry converting it from polygons to nurbs surfaces.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on December 31, 2025, 12:33:00 pm
Thank you!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 07, 2026, 02:59:18 am
Ok I did a test created an object in Nvil send to Moi...no problem....with create subD and import Obj both work good.

from Moi export as obj ...merge scene > select the obj file

I see the items in the scene hierarchy ...but nothing is visible

I need these to work to finalize 2 projects.

Tnx!
 


Title: Re: From Moi to Nvil and back how to stay accurate
Post by: IStonia on January 07, 2026, 04:09:33 am
Is the object empty? You can see the amount of polygons it has in the HUD display on top-left of the viewport.
If it is not empty. Select the object in hierarchy window, then View > Viewport Framing > Best Fit and the object should appear.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 07, 2026, 01:20:24 pm
Ok I am getting somewhere.
In Moi I am drawing in cm. In Nvil I set it in cm.
When I do the viewport fit I can see it ...but I am confused if it is way too big or way to small as I cannot see the grid.

so I send it back to Moi and it is 10 times smaller.
so I either have an export or import problem.

Attached is the object at size in obj.

Tnx!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 07, 2026, 01:21:20 pm
Attached obj
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: IStonia on January 07, 2026, 08:12:26 pm
There are obj import/export scale options, Edit > Options > File Format Options > ...
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 07, 2026, 11:35:23 pm
Ok so I made a cube 10x10x10cm In Moi export as obj re import in Moi and the dimensions are right.
I imported it in Nvil in the file import options I set the import to scale at 0.1 import /export is set at 1.0 the cube and export open with Moi
and the cube is now 11x11x11cm.

So it is close but is this the way to do it?
I have seen the video of the design rage robot where he imports back and forward and seems to go 1on1 scale.

Am I missing something?

Tnx!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: IStonia on January 08, 2026, 12:54:23 am
I don't have Moi, so can't answer that.
Are there scaling options in Moi's import/export?
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 08, 2026, 01:38:51 am
Ok I think I got it.
In Nvil import scaling is set at 0.01 but no matter what I did on the export side it will not come correct in Moi3d.

But I found a setting in obj import and changed to 0.909 instead of 1 and now it seems correct.
but there is something weird I made a cylinder 50cm diameter send to Nvil...it seems in Nvil it is 46cm
save open in Moi it is 14cm :/
Now it would not matter whatever the size I have in Nvil...but what matter is from Moi to Nvil and back it should be the correct size. anyone knows if https://www.youtube.com/watch?v=vMFqGodNlno
Luka Mivsek is a member of this forum...he might be able to help out..since he is going Nvil, Moi and back
I use these to make stuff on cnc machines so I need the dimensions to be right.

I am using open scene and save scene as.
Is this the correct way to deal with obj files?

Tnx!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: kevjon on January 08, 2026, 01:46:35 am
I just did another test.

I set MoI to meters
I created a 0.1m x 0.1m x 0.1m cube in MoI.
Exported the cube from MoI to obj

I set NVil to meters in preferences
Merge Scene > obj
I set import scale to 1
I used the measure tool > measure between snap points
It comes into NVil perfectly to size at 0.1m

If you set NVil preferences to cm and import scale to 1 it comes in perfectly to size also.

I tested your wheels 1302.obj file
When NVil is set to meters and they are imported at 1 scale
Each wheel is 43.7721m diameter x 26.9996m high
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 08, 2026, 02:08:28 am
Can you test this 50cm cyl. Moi Nvil and back to Moi?

Tnx!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: kevjon on January 08, 2026, 02:22:20 am
You cannot import mesh data from NVil into MoI v4 (except when using the subd tool in MoI)

If use MoI > subd > create tool to import the obj data it will convert it to a subd nurbs surface which will change its size slightly as the subd algorithm tries to round off all the edges of the cylinder.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 08, 2026, 02:28:34 am
I use the import obj script then subd in Moi. so I can boolean fast and accurate.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: IStonia on January 08, 2026, 02:29:15 am
There is a setting need to be noticed, View > Scene Scale. It affects the size of the floor grid. The default value is 1. In your case, you can set it to 0.1 so you can use 1on1 scale on import/export.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: kevjon on January 08, 2026, 02:41:32 am
Do you have a link to the script you are using ?
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 08, 2026, 02:47:24 am
Here is some links and info...https://moi3d.com/forum/lmessages.php?webtag=MOI&msg=10945.1

Hopefully I got this now....there seems to be an issue with the import obj which changes the size.
so this is fixed now...but when importing it was 100x smaller so I changed the export scale in Nvil and now it seems spot on...going to test some more tomorrow.

tnx.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: kevjon on January 08, 2026, 03:18:38 am
Ok, sounds like you've sorted it out.
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: Noobnvil on January 08, 2026, 07:37:27 pm
One more question...does Nvil include Matcaps or should I just download them somewhere?

Tnx!
Title: Re: From Moi to Nvil and back how to stay accurate
Post by: IStonia on January 08, 2026, 10:43:38 pm
You need to google and download matcaps.