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OBJ + MTL in 2020 ?
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* July 19, 2020, 05:19:42 AM
Hi !

https://www.turbocad.com/content/turbocad-2020-file-format-comparison

Sadly, this interoperability comparison listing does not mention an OBJ's MTL...

Import / export of an OBJ's companion MTL file is not supported in my Pro_2016. I've read it was expected in Pro_2017, may have slipped to _2018 or beyond...

What is the current status, please ??

It is really, really annoying having to explode & split each OBJ to coloured / textured layers at TC import, then post-work edited OBJ in eg free 3DOC Viewer to set texture calls and create MTL.

Nik

( Though FBX is now 'supported', my experience of other programs' FBX I/O is 'unhappy'. That's a different can o'worms...)

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* July 25, 2020, 06:59:58 PM
#1
Any-one using OBJ+MTL ??

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July 26, 2020, 04:51:36 AM
#2
I have only experimented with it.  I have files indicating I explored OBJ files with MTL back around 2017 and again in 2018.  I'm pretty sure I'm getting what is expected.


Jeff

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TC Pro Platinum 2020, 2019, 2018, 2017, 2016 & 2015 (all with LightWorks & RedSDK) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1


* August 01, 2020, 04:25:52 AM
#3
Jeff, thank you for replying.

Without an associated MTL file, it is very, very difficult to import, edit then export a 'busy' OBJ. Did you get an MTL ? My 2016 TC ProP offers no obvious options that might enable its I/O.

I've been gifted several OBJs whose MTLs make ~1000 external texture calls. I dare not edit nor adapt these near-photo-real architectural models with TC because it is impracticable to reconstruct their MTLs in post-work.

FWIW, TC 2016 does not support FBX, but I have analogous problems in other programs when an FBX has been exported without texture calls. Aside from FBX version 'tree' issues (v6 'trad' vs v7.1~7.4 'trad', 'mutant' and 'splat') even when a folder of texture files is supplied as solid colours or maps, matching 50~~90+ parts to their textures is non-trivial...

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August 03, 2020, 02:38:55 AM
#4
Without an associated MTL file, it is very, very difficult to import, edit then export a 'busy' OBJ. Did you get an MTL ?

After TurboCAD became able to utilize the Material specifications, I found a few files that had both OBJ and MTL and did a very few experiments.

Re-doing them right now with 2020 indicates I may not be getting the results I should expect (but that could be an oversight on my part).

My suggestion would be to get a screen capture or PNG export in the desired resolution from an original installation, then see what TurboCAD does with the same files.

However, I Saved As OBJ (see attached image) and the resulting output did not include a MTL file.  I reviewed the settings in Setup and there wasn't an option, either.


Jeff

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TC Pro Platinum 2020, 2019, 2018, 2017, 2016 & 2015 (all with LightWorks & RedSDK) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1


* August 03, 2020, 07:46:47 AM
#5
Sounds unlikely, to me.  Currently there's not a lot of equivalence between Lightworks and RedSDK materials, while .mtl format would add a third, along with the xref .jpg library needed - and that's for export.  Import would have to subjugate TC's material/colour structure to the external writer, and then interpret native lighting and luminance to try to match that. 
Along with that, the format notes add:
Other potential interoperability issues: According to the Interchange section of the Lightwave 3D reference manual, "OBJs textured with image maps or numeric values in other packages will come in textured but nodal or procedural textures will not translate in either direction. Autodesk’s Maya and Max reverse diffuse and ambient, so the default behavior of LightWave now is to reverse Ka & Kd for OBJ export. If you find that textures are being transferred incorrectly, try switching this off in the Layout Preferences OBJ Tab or Modeler Preferences OBJ Tab." 
Sheesh. 

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* August 03, 2020, 10:26:43 AM
#6
Thanks.
I really appreciate your investigations.

I freely used 3ds files, with their baked-in colours, for FloorPlan v6~v8+ (Classic) <==> TC ~v9 <==> Poser_4, but TC *still* not having MTL support for OBJ I/O is dire news.

When a complex architectural 'set' OBJ has many, many materials, each with multiple texture calls, having an MTL is no luxury, but a screaming necessity.

I suspect TC FBX I/O support may be similarly flawed, as that format also provides for materials with texture calls... .
:-(

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* August 03, 2020, 05:48:57 PM
#7
I suspect IMSI's more concerned with geometry than trying to implement these, they don't have utility value within the program.   It's open format, but its value lies in those programs that implement proprietary usage.   You call it "flawed" because it doesn't comply with what your other programs want....

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* August 04, 2020, 04:05:25 AM
#8
That's a fair call, Murray, and thank you for picking up on my 'fringe' query.

https://www.turbocad.com/content/turbocad-2020-file-format-comparison

Perhaps this comparison would benefit from clarification...


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