3ds models - some work in external library others don't. What's the difference?

iiJDSii

I am using .3ds models in my Android software application. I have a library framework (min3D) for displaying them on screen. The example model they've provided ("monster_high.3ds") is displayed just fine, but other .3ds models I've downloaded from, say, Turbosquid, don't work (crashes the internal library, not able to debug so far).

A friend has told me that perhaps the models were "prepared differently", or follow a different format. I'm not sure what this means, I have a very limited background in 3d modelling. I would be super appreciative if someone could take quick look at a few of these .3ds files and see if there's something obvious/simple that separates "monster_high.3ds" from the others. What's the difference? How can I fix the others?

Here are the files:

"monster_high.3ds": http://ge.tt/17hU1uh/v/0?c (working)
"bench.3ds": http://ge.tt/7Mhn1uh/v/0?c (not working)
"cabinet.3ds": http://ge.tt/9f0H2uh/v/0?c (not working)

Thanks so much!

Eric Chadwick

.3ds is a shitty format. Take it from me, I've been using the 3ds software line (3ds Max, 3D Studio, etc.) since the early 1990's, back when it was in DOS. The .3ds format has all kinds of limitations and bugginess. Better to use another format, if you can. Like FBX or OBJ.

Eric Chadwick

bench.3ds has a hierarchy structure, 21 boxes linked to a non-mesh node (a "dummy" in 3ds terms), which is linked along with a cylinder mesh to a root dummy node. So three levels of hierarchy. This could be causing your troubles.

The monster 3ds file is a single mesh, no hierarchy. However it does have a ton of split vertices. This is a big limitation of the .3ds format, it doesn't support more than one vertex normal per vertex, so where there are multiple normals it splits the verts instead.

iiJDSii

Unfortunately I am stuck with the .3ds format. Min3D is one of the only workable Android libraries I've found for displaying 3D models, and it doesn't handle those other formats mentioned.

Eric - thanks for the response! Would it be possible for me to mend the other .3ds files into a similar format as the monser_high? I am new to 3D modelling, what software would I need to do this? Is there a tutorial I could follow for this process?

Eric Chadwick

Blender should be able to edit these files. I don't think there's a tutorial for this though. You probably just need to kill the hierarchy, and re-export.

If you want free help, you could put out a request here:
http://www.polycount.com/forum/forumdisplay.php?f=44

iiJDSii

I'd love to learn to do it myself. Downloading & installing Blender now.

Would you say this is an advanced operation or something I can pick up relatively quickly? Assume I'm a reasonably quick learner.

Eric Chadwick

Should be pretty easy. The tough part will be figuring out what's causing the crashes.