topic Re: Can't export .OBJ file keeping layers/groups in Alias Forum

Can't export .OBJ file keeping layers/groups

Anonymous — Mon, 20 Aug 2018 11:59:54 GMT

I am having some difficulty exporting a project which has three layers. I would like for these layers to be exported separately in an .obj file so I can have more control in 3ds max. I've tried turning on Object Groups in the export settings in Alias and grouping the 3 layers/objects beforehand but a soon as I import it into 3ds max I only get one object in the OBJ import options dialog box.

If I import .wire file into 3ds max all objects stay separated but I get too many polygons.

Thanks for the help.

Re: Can't export .OBJ file keeping layers/groups

rauscht — Tue, 21 Aug 2018 13:20:36 GMT

Hi,

if I got you right, you should be able to achieve 'One OBJ file per layer' as follows:

Organize your wire file by layers
For each layer:
- Make the layer the active one (by clicking into it's tab in the Layer Bar)
- Use "Layers" > "Select" > "Objects on Selected Layer" to select all object on that layer
- Use "File" > Export" > "Active As" (push the tiny rectangle to open the "Save Active Options" dialogue)
- Choose "File Formats" := "OBJ" and adjust other OBJ options as wanted and push "Save" button
- In the file chooser dialogue type the wanted file name

Please let me know if that resolves your issue.

Thanks

Thomas

Re: Can't export .OBJ file keeping layers/groups

Anonymous — Tue, 21 Aug 2018 19:20:57 GMT

Hi Thomas, I want to have multiple objects in one .OBJ file, in this case 3. So when I import the .OBJ file into 3ds max, I then have 3 objects/editable polys and not one single mesh.

All though I had to, I do not want to create 3 separate .OBJ files and import them one by one into 3ds max.

Hope this helps.

Re: Can't export .OBJ file keeping layers/groups

rauscht — Wed, 22 Aug 2018 10:52:39 GMT

Hi,

still, I am a bit uncertain on what it is that you would like to achieve. Allow me to use my own words to describe your requirements.

You have three geometrical objects in your wire file (let's say three NURBS surfaces or meshes). You want to transfer those to 3ds max (by using OBJ file format). In 3ds max the wanted result should be one mesh which represents all three geometrical objects you have started with. Is my understanding correct?

If that's the goal, one needs to observe that in general those three geometrical objects will be disconnected (position wise). For that reason, it is not expected that the export/import magically glues those together to one mesh. The usage of layers or groups (which both are semantical not geometrical grouping mechanisms) will not help here.

One way to proceed could be the usage of Palette > Mesh > Mesh Partitioning > Mesh Merge to make one mesh out of the three given. (In case of a NURBS surface you would need to use Palette > Mesh > Mesh Tessellation > NURBS to Mesh first.)

Hth

Thomas

Re: Can't export .OBJ file keeping layers/groups

Anonymous — Wed, 22 Aug 2018 11:46:54 GMT

Thomas,

to understand what I want to achieve please download this wheel model and import Temp Chiron Rims.obj into 3ds max. When you do you will see that the surfaces are separated as objects, 22 objects to be exact. When imported into 3ds max you will get 22 separate editable meshes - unless you select Import as single mesh of course.

Just to be clear here is a photo from 3ds max when importing the file I mentioned.

I want to export an .obj file from Alias in which surfaces will stay separated just like above. I have many surfaces but I would like to group them in 3 groups which would then become 3 editable meshes when they are imported into 3ds max. So this would be ONE .OBJ FILE where the import dialog would show 3 OBJECTS.

I've already tried grouping them in Alias and selecting Object groups in the .obj export window but it does not work. It always combines them into one mesh.

Re: Can't export .OBJ file keeping layers/groups

systembolaget — Wed, 22 Aug 2018 15:52:46 GMT

I have an office chair model here, with 37 major parts.

In order to render and animate, one would want a single OBJ file, like an OBJ group from SolidWorks or Rhino, and the 37 parts arrive in Maxwell Render, ready to have materials assigned.

Having to save and import 37 separate files is very tedious. I think this is what he refers to.

Re: Can't export .OBJ file keeping layers/groups

rauscht — Thu, 23 Aug 2018 09:58:25 GMT

Hi Rex,

now I got it what you are looking for. Thanks for clarification.

After some investigation I am afraid to say that the current Save As Obj export as provided by Alias today does not act the way as you are expecting it to do. Using the 'Object Groups' OBJ option triggers the creation of a group for every object contained in the wire model. Alias layers and groups do not contribute to this.

I have filed an improvement request which targets your needs.

Hth

Thomas

Re: Can't export .OBJ file keeping layers/groups

Anonymous — Mon, 13 Jul 2020 09:29:37 GMT

It would indeed be a very useful to be able export OBJ files with the group information intact. I am looking forward to having this function in the future. Thank you to the Autodesk development team.

Re: Can't export .OBJ file keeping layers/groups

BarryKimball — Mon, 13 Jul 2020 15:09:47 GMT

Why do you need to use OBJ?

Re: Can't export .OBJ file keeping layers/groups

systembolaget — Mon, 13 Jul 2020 16:40:31 GMT

OBJ export, ideally with UVs, is essential to use all modern high-end rendering software.

Re: Can't export .OBJ file keeping layers/groups

Anonymous — Mon, 13 Jul 2020 16:53:05 GMT

Hi there Barry, thanks for your reply

I have a similar problem to the post above. (systembolaget in reply to: nakuteop

08-22-2018 08:52 AM)

I have a model split into groups and a hierarchy. I need to export it as OBJ to import it into another software.

OBJ is a universal format which the other software can import. (I know OBJ is an old Wavefront format, so I would have thought it would be working seamlessly with Alias)

I do not want to have to regroup, change pivot points, reassign shaders etc etc, again, in the other software, when I've already done the work in Alias.

I think there are two possible reasons why this doesn't work:

Perhaps the OBJ format does not support hierarchies (groups) anyway?

Or perhaps the export as OBJ function in Alias could work better with exporting models with a hierarchy?

Re: Can't export .OBJ file keeping layers/groups

BarryKimball — Mon, 13 Jul 2020 18:22:18 GMT

I was not aware that all modern high-end rendering software's used a 20 year old format to exchange data. I don't have the data to check...but I highly doubt someone created UV maps in Alias...bt I could be wrong...the UV tools in Alias have not been touched in...ummm...probably since Maya was created.

Re: Can't export .OBJ file keeping layers/groups

BarryKimball — Mon, 13 Jul 2020 18:20:25 GMT

I suggest trying to use FBX to exchange the data between Alias and 3DSMax.

Re: Can't export .OBJ file keeping layers/groups

systembolaget — Mon, 13 Jul 2020 21:02:13 GMT

@BarryKimball wrote:
I was not aware that all modern high-end rendering software's used a 20 year old format to exchange data. I don't have the data to check...but I highly doubt someone created UV maps in Alias...bt I could be wrong...the UV tools in Alias have not been touched in...ummm...probably since Maya was created.

All high-end rendering softwares can only be used via OBJ as they all don't offer an Alias plug-in.

Since many years, the alternative to OBJ export is to go through Rhino via STP, which is really silly. And even stranger is the fact that Rhino exports OBJ with UVs, a format originally developed by Alias/Wavefront. All top renderers have Rhino plug-ins. The only renderer that imports Alias wire files at least is Keyshot, but that is an overpriced toy that can't even simulate PBR hair, carpet, grass, sea waves, clouds, subsurface scattering materials, dielectric materials, has no Substance Painter or Mudbox integration, etc.

Re: Can't export .OBJ file keeping layers/groups

BarryKimball — Tue, 14 Jul 2020 17:02:39 GMT

Ok...I am going to leave you with your thoughts about high end renderers and OBJ...If you believe the industry standard for data transfer between Alias and "all high end renderers" is OBJ I wont argue the point.

Maya can read wire files...VRED can read wire files...

If you made UV maps in Alias I imagine they would transfer via OBJ...

Please see this article from 2014 that explains how 3DSmax can read wire files...might help

https://knowledge.autodesk.com/support/alias-products/learn-explore/caas/CloudHelp/cloudhelp/2014/ENU/Alias/files/GUID-4EDFB9D1-C2C6-48FB-AA38-6AF02F711908-htm.html

Re: Can't export .OBJ file keeping layers/groups

Anonymous — Tue, 14 Jul 2020 19:23:27 GMT

I will try this, thanks

Re: Can't export .OBJ file keeping layers/groups

systembolaget — Tue, 14 Jul 2020 20:42:23 GMT

Sorry, but why such a snide remark? Since 1991, I have not experienced such blanket dismissal of user concerns (apart from those related to the still lacking proper undo functionality). Is that a novel Alias/Autodesk CRM approach?

Thomas Rausch, in contrast, has always explained issues and the reason behind them, without belitteling users.

Re: Can't export .OBJ file keeping layers/groups

BarryKimball — Tue, 14 Jul 2020 22:56:53 GMT

....I am sorry you feel my response was snide...

I am not a 3DSMax rendering expert...so if your tired and true workflow is OBJ to transfer data I don't want to talk you out of it.

Your comment that wire files cannot be read into 3DSMax was incorrect...so I simply pointed you to an article that explains how it is possible. Other users are reading these posts and when incorrect information is presented I believe it is necessary and proper to correct it...

Thomas's proposed solution was rejected...so I suggested 2 alternatives...in my view that is supporting users today, not in a future release that offers no path right now...

Re: Can't export .OBJ file keeping layers/groups

systembolaget — Wed, 15 Jul 2020 06:51:27 GMT

Thanks. The workaround via Rhino (or, as you suggest alternatively, Maya) does work. So let's let it rest : )

Re: Can't export .OBJ file keeping layers/groups

systembolaget — Tue, 18 Aug 2020 14:54:59 GMT

OBJ export now with Normalize UV Coordinates in V 2020... a very useful step forward for Maxwell, Vray and Octane users.