Importing OBJ vs Importing FBX

Scavenger

I'm trying out this nice freebie chair: http://www.modelplusmodel.com/furniture/seating/chairs/f16-chair.html

It comes in a variety of incompatible formats, but also OBJ and FBX

In the picture below, the grey is the obj, and the colored is the FBX.

The FBX imports with several different surfaces, so texturing is simple.
The OBJ imports with only one surface.

HOWEVER, for some reason, the FBX has all those chunks missing (in the blue areas). Since these would have been generated from the same original (3DS) model, they should be the same.

Is this something I'm doing wrong in the import? FBX import seems pretty automatic (as opposed to obj). Is this a DAZ STUDIO problem with the import? (I had this same problem with another of their models, so it could be an issue with them).
.

Richard Haseltine

The OBJ doesn't contain any surfaces - there are no group markers in the file viewed in a text editor. The FBX has missing polygons in modo too, though not as many as in your screen shot. The DXF loads into modo intact, but again no surfaces. There's nasty flcikering when I pan the view in DS, which suggests a doubling up of geometry which may make it unusable. On the plus side it is fairly simple to assign surfaces using the Geometry Editor tool - select by dragging one or more polygons on the seat, press ctrl(Win)/cmd(Mac) * to select all connected, right-click, Geometry Assignment>Create Surface from Selected..., right-click>Geometry Select>Clear Selection, repeat for other parts as desired (for the rivets I created a surface from the first, then used right-click>Geometry Assignment>Assign to Surface>Metal-rivets for the others). It seems to have worked OK using some of the stick Iray sahders.

jpb06t

Imported the OBJ into Blender, added two materials and assigned the appropriate polys, brought into Studio, set two stock Iray shaders and rendered. The only problematic item I found were the dimensions (apparently the chair was modeled at 1 OBJ Unit per millimeter scale).

Takeo.Kensei

Same result as Richard for the Fbx and Obj
The 3DS file seems to have everything correct. Imported in Blender and exported as Obj then import in DS

mjc1016

With the problems in the mesh in the other formats, I'd guess that it was originally saved as a 3ds file and run through an autoconverter to get the obj and other formats...and each one was from one of the previous conversions.

The more conversion something goes through, the greater the chance of something messing up. A single conversion, in a program that handles the item's 'native' format is the best way to convert from one format to another, if you don't save from your modeler in a particular format.

Scavenger

Richard: I think your definition of "simple" and mine are different, as selecting the right polygons from the wrong ones in Geometry Editor are a PITA, especailly as there's no face zones.

(I don't know actually what a face zone is vs a surface, but they may selection easier, such as the imac in my other post..though the OBJ of the imac has all the surfaces already)

MJC: thanks for the answer/explanation (since I don't have blender or 3ds max to import/export with). I'll contact that site and mention the problems (if they wish to fix them).

Edit: though looking at the FBX in Autodesk's FBX viewer (shame it's not a converter too) and the surfaces are fine. Must be the doubling Richard mentioned causing issues.

Richard Haseltine

You don't have to select all of the polygons, just select one and then hold down ctrl(windows)/cmd(Mac) and press the * key - that will select all of the polygons connected to the selected polygon (which in this case is probably what you want, unless you want to treat the top of the panels differently from the sides and back).

Bejaymac

I suspect it's a Boolean issue with the FBX importer, you also have the problem that there's no UV data after importing.

Looking at the different files I'd say it was made in MAX and then exported in the different formats, if had been saved as 3DS and then converted then all of the models would be tri poly, as that's all that ancient pos of a format can cope with.

mjc1016

Bejaymac said:

if had been saved as 3DS and then converted then all of the models would be tri poly, as that's all that ancient pos of a format can cope with.

Yes, but Max can save as a 3ds file...and some of the problems with the others remind me of crappy conversions back to quads from tris, when converting that format to anything else.

My guess...the Max file was the 'native' save...the 3ds save was the attempt at a 'universal' save...and the rest went downhill from there.

mjc1016

Here's my process...

1. Import the 3DS file into Blender. It, for once was actually the nicest, cleanest version to import into Blender, and like Takeo said, all the materials were properly defined. Then I flipped over to Edit mode. There I converted it to quads and selected a couple of edge loops around the seat and back. Then unwrapped it.

2. I then exported it as an obj.

3. Imported into Studio, rescaled it and saved it as a Prop Asset.

4. Then I Googled that chair and went to a website selling them (the real chair) and looked at the colors it comes in. Then I used a color picker to select each color and in the Surface pane, for the seat material, entered each color, saving each one as a Materials Preset. Did the same for the wooden one...which was the reason for UV unwrapping it.

Now, most of those steps can be done in any modeler that can import 3ds files.

kyoto kid

...request for Daz 5.0 -.3ds file import.

Richard Haseltine

Kyoto Kid said:

...request for Daz 5.0 -.3ds file import.

Could be done by a third party, as a plug-in (which is what a lot of the importers, including the Poser importer, are).

jpb06t

Try PoseRay. It (among lots of POV-Ray related functionalities) reads many 3D file formats and can write OBJs.

kyoto kid

...I never could get that to work right and preserve material zones. I do not have a good stable modelling programme to redo the UV mapping with either.