[Plugin] Import OBJ with Materials v2.1 20131118

TIG · 1 Aug 2011, 15:33

No!
A GOOD OBJ exporter typically makes copies all of the linked image-files either in the same folder as the OBJ, OR better in a subfolder called Images or XXX_Images or XXX_Textures, where XXX is the name of the OBJ file - OR it just fails to export them like 'tree3d.exe'.
The OBJ file says which MTL file it's using in the first few lines of code - typically it's just a name and the MTL is a file in the same folder as the OBJ, with a matching name but the .mtl suffix.
Then for each collection of faces defined in the OBJ it sets the material 'by name' that it'll be used for those faces, and there's a list of materials 'by name' defined within the MTL file - each with its own color, transparency, texture etc.
The MTL file sets the path to an image-file, if any, because an MTL can just be a 'color'.
That path as I said is typically to a file in a subfolder, kept with the OBJ/MTL, that holds jpg/png files, named exactly as specified in the MTL file...

An OBJ importer looks for the MTL file... and if it exists then it applies the materials in it to the appropriate face-sets... it looks for the specified image-file [if any] for each material and if it's found it then uses that too...

If you have the image-files it's a simple matter of putting them in the path specified in the MTL - in my experience I have never seen anything other than a list of file names [i.e. the image-files are in the same folder as the MTL file OR more commonly the image-files are in a subfolder kept with the MTL file

IF the MTL file is 'messed up' then manually edit it to repath each of the image-files defined in the lines starting 'map_Kd ' thus:
map_Kd Images/image1.png
and where 'image1.png' id the name of the file you have that should be used...
and where you have made a new folder called 'Images' kept with the MTL file and you have put all of the image-files in there!

Arzka007 · 1 Aug 2011, 19:46

"A GOOD OBJ exporter typically makes copies all of the linked image-files either in the same folder as the OBJ, OR better in a subfolder called Images or XXX_Images or XXX_Textures, where XXX is the name of the OBJ file"

I couldn't agree more that that's the way is SHOULD be done. However, many programs, for example popular 3ds Max, don't do it that way by default. (Why not, I have no idea.)

When you save an object from 3ds Max in OBJ format (using default settings), linked image-files are NOT copied to the folder where OBJ and MTL files are saved. MTL file only contains links to original texture folder.

And when people try to open these files (in other computers) they can't see textures... And they keep filling forums with questions like "missing textures when opening OBJ file" (as seen in this thread also).

But hey, who cares, let's forget the whole thing!

TIG · 1 Aug 2011, 20:07

http://forums.sketchucation.com/viewtopic.php?p=284378#p284378
explains how OBJ should be exported from 3dsMax...

Because an MTL is a text file it not that hard to find every image file in the list and remove all but the file name from the path, the replace the first part with a folder path
So
map_Kd SomeFolder/SomeOtherFolder/YetAnotherFolder/Images/image1.png
becomes [if the folder path is always the same a bulk Find+Replace edit is possible]
map_Kd image1.png
then you use a bulk Find+Replace ' map_Kd' >>> ' map_Kd Images/'
so you have
map_Kd Images/image1.png
etc for all of the image-files...
Then move all of the image-files into an 'Images' folder with the MTL...
It should work fine...

thomthom · 22 Aug 2011, 09:10

Got a feature request: Make it use the Importer class: http://code.google.com/apis/sketchup/docs/ourdoc/importer.html

That way it can be found under the native importer options.

thomthom · 22 Aug 2011, 09:11

hm...

Importing a OBJ file now, I'm getting lots of Error: 666 in the Ruby Console.

TIG · 22 Aug 2011, 09:33

Sometimes OBJ files throw an error [I suspect that it depends how they were 'written' originally - there are several different 'formats' - e.g. define some vertices then related faces per group... or define all vertices then all faces en mass; which is more difficult to read 'manually' too] - the geometry for the face is invalid - the three points are perhaps colinear or [effectively] coincident - so I get it to put up an error instead of crashing... The 666 is a longstanding joke with Rich http://forums.sketchucation.com/viewtopic.php?p=316402#p316402
Although it throws the errors up it usually seems to make the expected geometry - so it's difficult to see what's 'gone wrong'
You can of course easily tweak the 666 rescue message to include the Exception - but frankly I found that little use either...
My importer is not [always] as good as the compiled dll version that is available.
For MAC it is the only option.

thomthom · 22 Aug 2011, 09:37

There is a compiled version?

TIG · 22 Aug 2011, 09:40

@thomthom said:

There is a compiled version?

Here http://forums.sketchucation.com/viewtopic.php?p=316470#p316470
Fluid's free OBJ importer [PC only]...

Rich O Brien · 22 Aug 2011, 11:01

Fluid obj importer in the extensions forum.

Rich O Brien · 22 Aug 2011, 11:03

Sorry, I posted this earlier but lost web connection.

niks · 20 Sept 2011, 10:57

hi Tig..thank you for this ama ing...plugin

capsssa · 6 Oct 2011, 09:15

Please,
i need help.
I've got the version 7 pro, i am on a mac, but when i installed this plugin it doesn't work.
I am on a mac. When i poen sketchup the plugin is absent.
Can you help me, please ?

TIG · 6 Oct 2011, 14:51

You have probably installed it in the wrong folder - check where your MAC Plugins folder is and ensure you put it in there...
It is accessed off the Plugins menu.
I would recommend the FluidImporter but I think it's PC only...

chippwalters · 20 Jan 2012, 04:44

Hey TIG,

How come this file (simple) won't import with map? I created it using UV Mapper Pro, which is pretty standard IMO. Any insight you might have would help greatly!!!

Dropbox - 404

(dl.dropbox.com)

TIG · 20 Jan 2012, 09:49

Chipp

This tool is now plenty old and there's a much better/faster [free, PC only] one available here...
http://forums.sketchucation.com/viewtopic.php?p=316470#p316470
[follow the link to the download page here
http://www.fluidray.com/downloads]
I recommend you try that.
Here's its result, which I take is what you want ?

chippwalters · 20 Jan 2012, 10:05

@tig said:

Chipp

This tool is now plenty old and there's a much better/faster [free, PC only] one available here...
http://forums.sketchucation.com/viewtopic.php?p=316470#p316470
[follow the link to the download page here
http://www.fluidray.com/downloads]
I recommend you try that.
Here's its result, which I take is what you want ?[attachment=0:2wlcddqw]Capture.PNG[/attachment:2wlcddqw]

Thanks TIG. Just what the doctor ordered
I'm using a Mac these days, but I've got a Virtual Win version of SketchUp. I'll check it out!