[Plugin] Import OBJ with Materials v2.1 20131118

Jim

Line 248:


values.each do |v|
w = v.split("/")
vvv = Integer(w[0])
if vvv <= -2 # this 
  vvv += 1
end
face<<Integer(vvv)
face_uvs.push(w[1].to_i)if w[1]

And maybe look at fill_from_mesh instead of a dd_faces_from_mesh. # Line 302. Probably left over from someone else..

I'm shocked it actually seems to have worked - it was just a hunch.

TIG

Here's a slightly different version that I was working on independently - it also works !
http://forums.sketchucation.com/viewtopic.php?p=172790#p172790 [v1.7 has fill from mesh changes too]

thomthom

Any ideas what caused these glitches? http://forums.sketchucation.com/viewtopic.php?f=323&t=20584&start=75#p264875

TIG

Thomthom, I assume you are referring to the size/units ?
If the file has a '# units = meters' line then the importer defaults to 'meters' [or whatever it says].
If it doesn't then it defaults to 'inches'.
However, as it starts a dialog lets you choose whatever units you'd like to use anyway [preset to those default units].
Some meshes don't form the tiny faces if the units are set too small - e.g. if you were to choose 'mm' when it was made in 'meters'. So if you are unclear about the units and none are specified then you can try out alternatives until you get a proper mesh without holes...
The reason the tool has three options is speed - 'as mesh' is fast but can fail when the OBJ code is convoluted; otherwise the textures can be added or not as desired.
The old sizing issue seems resolved.
PS: I can't tested your problem 'van' OBJ/MTL because PPartner010000.jpg wasn't in the zip file?
But I can see that its geometry seems a bit messed up around the side windows and the image file-names have spaces in them which confuses the MTL parser. I thought that you were 'recommended' to avoid having spaces in these paths/names - however, manually editing the MTL and the corresponding image-names so they are without spaces fixes that... BUT the 'PPartner010000.jpg' file is still missing altogether - see the Ruby Console error reporting

TIG

Busy today! Heres 1.8 - Trapped for spaces in image-names/paths.
http://forums.sketchucation.com/viewtopic.php?p=172790#p172790

thomthom

@tig said:

Thomthom, I assume you are referring to the size/units ?

No - it was the messed up geometry you noticed. You see it in the screenshots I posted - with the red circles.

@tig said:

PS: I can't tested your problem 'van' OBJ/MTL because PPartner010000.jpg wasn't in the zip file?
But I can see that its geometry seems a bit messed up around the side windows and the image file-names have spaces in them which confuses the MTL parser. I thought that you were 'recommended' to avoid having spaces in these paths/names - however, manually editing the MTL and the corresponding image-names so they are without spaces fixes that... BUT the 'PPartner010000.jpg' file is still missing altogether - see the Ruby Console error reporting

The OBJ was initially created by SketchUp - then edited textures in PhotoShop.

I've attached the missing texture.

Will try v 1.8

missing texture

thomthom

Even with 1.8 some geometry is messed up. Seem to be the same faces.

TIG

I see the messed up UV textures.
I re-imported it as 'mm' and the messed geometry went.
BUT I had to edit the faulty UV mapped parts manually.
As it's symmetrical a quick mirror/copy of the correct panel on the other side fixed them.
The 'Badge' is messed up though - did you map that on separately ?
I've no idea why just those few parts fail to map properly
VAN.skp

thomthom

I import in mm - but it's not just the UV being messed up. It's the actual geometry.
Notice that for the incorrect mapping the face is split diagonally-crossing itself - as opposed to the mirrored side.
When you compare against the 3ds import you see that Max does not do this.

I did not do anything to the mapping other than take the OBS into PS and adding the text on the side of the van. The model came from a pre-modelled and pre-mapped third party model.

I wonder if it's the order of the vertices that's abnormal in these cases... ?

TIG

The cross-threading of the faces' vertices into 'bowtie' triangles - which then probably mess up the UV-mapping - must be in the OBJ file itself [?].
The OBJ Importer simply uses the f n/n nn/nn/ nnn/nnn... values to form the faces and mapping ? Unfortunately unless you can reproduce the problem in a file with relatively few faces it'll be all but impossible to plough through the data to find the problem instances... [+460+ faces here?].
I was hoping that the OBJ had some -ve face indices that were causing the problem which recent versions might have solved... but NO!
In SUp export the ordering of a face's vertices shouldn't be a problem as they should always return ordered, and in the correct 'clockwise-ness' for the face's normal direct ?

Jim

The vertexes in the 'f' line are out of order for whatever reason.

Creates a "bow tie":

Sketchup.active_model.entities.add_face([0,0], [1,1], [1,0], [0,1])

thomthom

So it's the OBJ data that's invalid... but Max manage to deal with it somehow.

I'll compare against the raw output from SU and see if it's SU or PS that mangles the geometry.

thomthom

It's SU generating the odd vertex order. Here's the OBJ directly from SU:

SU Export

TIG

Could you PM me the original textured SKP - I have a new embryonic OBJ-Exporter that might NOT do this glitch ?

notareal

Here is a model that seems to fail http://www.fileden.com/files/2009/5/30/2461193//dragon_scene_OBJ.rar (From CGTalk Frosted Glass Challenge). Maybe it's a bit large... but simlab obj importer seems to handle it.

honoluludesktop

TIG, Wow, nice piece of code. Lots stuff I have to learn, like next, case, when, def file.run(par1, par2), etc. Makes the code look more compact and easy to read. Oh well, if I looked here before starting what I am working on, I may not have understood:-)

Some of the stuff that's driving me nuts when writing importers, is that different exporters do not format the data exactly. SU's DxfIn treats "10", and " 10" equally, and many exporters ignore the convention that is " 10". I don't know if I should go back and fix my code to read "10" or not. It's no problem for my use, and would like to "share", but am concerned about posting something that may not work for some.

TIG

honoluludesktop
A DXF has alternating lines for 'code' and 'value'.
So if it's an odd-numbered line then it's always 'code' and if it's an even-numbered line it's always the previous line's code's 'value'...
It's a DXF convention to indent the 'code' number, BUT it's not necessary and any importer should strip off leading spaces anyway...

  0
SECTION
  2
HEADER
  9
etc

is the same as

0
SECTION
2
HEADER
9
etc

To see a DXF 'parser' look at my DXF Text Importer http://forums.sketchucation.com/viewtopic.php?p=194488#p194488

honoluludesktop

OK, thanks, I will look at it. I may have to wait for a complete rewrite to parse the 'code'. Isn't some of that done in the Obj translator? I couldn't tell since I am not at all familiar with Obj.

When I think about it, any translator can be a modular app., just as you did with the text importer as a supplement to SUs DxfIn. My own interest has been limited to very basic geometry, and dealing with the anomalies of my Cad's DxfIn/Out. It suits me since I use SU exclusively for visualization and modeling, and Cad for functional diagramming and production drawings. Accordingly, I only require the basic geometry to pass between SU and Cad.

onesimo

hi tig! thanks for the importer. its working perfectly for me on my archmodels.
i should have tried it when i first saw the post. thanks so much and i really appreciate your work.

onesimo

hi tig! im using 3ds max design 2011. when i open/obj import my exported file the textures are not showing.. it seems my .mtl file is different from the one posted (the one with the building). thanks!

my exported file from 3ds max