[Plugin] Import OBJ with Materials v2.1 20131118

TIG · 16 Apr 2011, 22:00

Immer

I'd be more than happy for you to take over 'my' OBJimporter - 'Fluid' has recently made an equivalent compiled version [currently PC only].
BUT if you want to redo aspects of my stuff then please do so and publish them - I only want credit/blame for my bits [note that several others also made earlier contributions to this 'collaboration' !].
You can start a new thread [then I'll edit mine to direct new browsers to yours...]
I have too much on right now to do many changes to tools that I feel are now 'spent'...
BUT if you can improve it please do so

Immer · 16 Apr 2011, 23:55

Thanks, but I've got enough projects on my plate already, I was just lopping a few warts off a new tool in my box. I've seen Fluid, but my main dabbling machine is an old Mac so it's not convenient to use.

I can completely relate to not wanting to make frequent updates to old projects though, so here's my faster version for anyone interested.much faster version that also reuses existing materials instead of leaving objects untextured

chango70 · 23 May 2011, 15:03

@immer said:

Thanks, but I've got enough projects on my plate already, I was just lopping a few warts off a new tool in my box. I've seen Fluid, but my main dabbling machine is an old Mac so it's not convenient to use.

I can completely relate to not wanting to make frequent updates to old projects though, so here's my faster version for anyone interested.[attachment=0:1hpltocr]obj_importer.rb[/attachment:1hpltocr]

Cool will give it a spin shortly.

Cheers

gmfs1410 · 23 Jun 2011, 21:09

TY ...

Danobe1964 · 7 Jul 2011, 10:53

This plugin is the missing link between SketchUp and "Bryce 7 PLE" (also free) that I use as a renderengine.
It is a perfect team and this obj-exporter is the hard to find plugin.
Many thanks!
Daniel

Arzka007 · 30 Jul 2011, 18:15

Great plugin, thanks.

However, I have a problem with many OBJ files I try to import to SketchUp... Textures are missing.

From previous posts i realized that this is not actually a "bug" in OBJ importer. The reason is that many OBJ files are originally exported with "hard coded" texture paths (instead of relative pathing). So OBJ importer is trying to find textures from folder that doesn't exist in my computer...

But hey, maybe it could be possible to do something for this?

Maybe you could add a setting for "default textures folder", so that OBJ importer would always look for textures from that user-defined folder (and it's subfolders) when OBJ file is imported? Or maybe textures that are in the same folder with OBJ file (or in /Textures folder) could be automatically imported with OBJ file?

I know that this can be done by editing manually MTL file that comes with OBJ file, but that's too much "hacking" for me... Especially if I have to do this with every sigle OBJ file that I import to SketchUp...

TIG · 30 Jul 2011, 19:43

The MTL file almost always goes in the same folder as the OBJ file - if you open the OBJ file in a text editor like Notepad it shows the MTL 'relative' path in the first few lines...
If you open the MTL file in a text editor like Notepad it shows the path expected to each of the image-files used for the textures. Simply place the image-files [if you have them] in the same relationship - either in the same folder as the MTL or a subfolder suitably named...

Arzka007 · 1 Aug 2011, 14:24

Yeah that can be done of course - it's just not always very handy.

For exaple, a guy who originally created the 3d object might have stored his textures into folder like this:

C:\Documents and Settings\Leonardo\projects\maya\sci-fi\spaceships\enterprise\textures

Before I could place my textures in similar location, I would first have to create folder "Leonardo", then subfolder "projects", then subfolder "maya" etc. As I said, not very handy...

Programs like "Accutrans" and "Deep Exploration" have this "default textures folder" function. Or, if they can't find textures either in folder that is defined in MTL file or in "default textures folder" they ask the user "do you want to locate textures manually?".

I just thought that OBJ Importer could have some similar function... But maybe it's too much to ask all the features that are in commercial applications from a free plugin...

(Don't get me wrong, OBJ Importer is really really great plugin already just the way it is.)

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 ?