OBJ file loses texures while modified in Rhino

Hello,

I have a problem while trying to modify the OBJ file in Rhino. It is a file showing the terrain model with ortho images as textures (>10 of them). I want to add some objects (raised lines on the terrain) and then have it 3D printed in full-colour. The issue is that when I export the modified file, it has no textures. I tried to modify the MTL file manually without success. The texture files are in the same folder as the exported OBJ.

I will upload the necessary files but have to know first, what do you guys need.

Do you have any ideas what might cause this problem? Is there a problem with import/export options or the file structure?

Thanks in advance!

Let me see if I’m following you right. You have an OBJ file (with mtl and texture files). That opens in Rhino OK. You add some geometry in Rhino. Then you export to OBJ and result doesn’t have textures. Does that sound right? Can you open the obj file in Rhino again and does it have textures?

Do your texture file names have spaces in them? OBJ export is supposed to replace spaces with underbars, maybe it’s not getting the texture files it writes named properly.

I guess what would be handy is the original obj/mtl with textures and the 3dm file you created by reading it in. For that matter the exported obj/mtl and textures would be good too. Better to have too much than too little.
Just make sure their labeled in a way that I can tell where they fit in the process. Thanks.

Cheers,
Tim

Yes indeed. There is a working OBJ file generated in Meshlab. It opens correctly in Rhino with textures. Then after adding the geometry and exporting, only an OBJ file is generated (with no texture files). I was trying to put original textures in the same folder. Then after opening back in Rhino it is just plain white while rendered (no textures) - same in Meshmixer and Meshlab. There are no spaces in names, I know this case.

I don’t have access to these files right now. I am going to send them tomorrow if it helps.

So here are the files attached. The original - working OBJ along with MTL and texture files and slightly modified .3dm file (just a test). Thanks in advance!

obj_issue.rar (17.3 MB)

I’m looking at this today, I was out for a while on vacation. Just making sure, do you have the “export material definitions” checked. It’s working ok for me. I did notice that textures don’t appear to be rendering right but that’s probably unrelated.

I just started using Rhino 6 today for a trial as I was using ver. 5 previously. Will be back in the office next week and going to check it out.
Thanks for Your answer and let’s keep in touch.

Kuba

Hey again!

Yes it works indeed in Rhino 6 but I have additional issues. First of all, as you have mentioned. Rhino is not rendering the textures properly. Why?

Besides, after exporting I cannot open the OBJ in Meshlab. I assume it is because of the way it looks (see screen attached). It opened in Meshmixed though. With which settings should I play to make the surface continous and have the added geometry look well?

Thank You very much for Your help!

UPDATE 2018-07-05

It doesn’t work anymore. There was some Rhino 6 update that I accepted. Following the same path as before. Rhino exports the file (either OBJ or VRML) without textures. Any ideas?

If you checked all of the boxes I had checked in my image that could be the problem.

I suspect the issues with meshlab might be the wrap long lines checkbox, it adds a slash character at the end of long lines and wraps them. Some apps don’t do well with that.

The other checkbox transforms what was the Zup axis in Rhino to the Yup axis in the resulting obj file. If you’re not familiar with what I mean odds are you don’t want that checked.

I have to ask others here about the rendering issue. It’s not clear to me what is, or isn’t, being set right on the materials from OBJ import. I did find that if you save the resulting model as a V5 model the textures display normally in V5…

I can’t repeat this. Can you please give me the exact steps you’re following to see the problem. Please also include the full version number you are using.

Thanks, yes indeed the ‘wrap long lines’ option was the one that messed the geometry.

I somehow managed to export it again using Rhino 5. I am really getting confused why it sometimes work and sometimes it does not.

Anyway, Rhino 6 holds this issue. The version I have is:
Version 6 SR6
(6.6.18177.16151, 26.06.2018)

I did what I wanted to but to be honest I am not sure if I would be able to repeat the process. Hopefully Rhino 6 will get the necessary fixes (such as proper texture visualization in render mode and non-problematic export to OBJ or VRML). Will keep you updated when I get back to this project as right now I will be waiting for 3D printed samples.

Thanks again!

Kuba