Mesh Webbing Distorts Uploading to Second Life

[Kitten]

When I complete a simple shape to import into SL from AC3D, I get webbing occurring between vertices on curves on the object. Usually, these do not show when uploading due to the limitations of the SL preview window, but once the object is imported, the shape is deformed with planes that totally distort the surfaces and function of the object.

I have tried several things, including triangulating the shape, but then I get several mismatched surfaces on the object that render it useless as I'm then unable to texture it properly. Resolving the object back into fewer surfaces only recreates the webbing issue.

What am I missing that is causing these (expensive and annoying) errors?
I saw some brief explanation given to another user, dated several years ago, but the program has been through many upgrades, and quite frankly, I don't know enough intricacies to properly name what is happening, much less solve this issue without step by step troubleshooting directions.

I attached the following pics to help explain. Hopefully, this helps someone else as well, as I know I'm not the only one experiencing this. Any help would be greatly appreciated because this alone has kept me from enjoying what AC3D has to offer.

Thank you and Cheers! ;-)

[Andy]

It could be because of the two large concave polygon sides. Everything is ultimately broken up into triangles and you can see that this has happened. Concave shapes can be unpredictable - depending on the triangulation algorithm used. It may be best to triangulate those surfaces in AC3D before exporting to SL.


I can see you are displaying normals so hopefully they are all facing outwards. You can also check by setting everything to 1-sided and if you see missing surfaces, then those sides need flipping.

[Kitten]

Thank you. I always make sure to display and check my normals before exporting and importing. As far as the concave surfaces, I have tried several objects using those, and none have worked successfully for me. Everything from a simple bottle or vase, to simple concave shapes such as this, and I always get that webbing, (unless I triangulate, which only breaks up the object's surface, as I mentioned.)

I have seen what people are capable of producing in AC3D, and to have this limitation is frustrating. If anyone has any solutions, please I would be happy to hear anything I can try to solve this.

Right now, I will try to break the object into two separate sides, and see if that helps anything. It will force me to work with two surfaces that need to be mapped and matched once imported into SL, but that may be my only option.

Thank you for responding. ;-)

[Andy]

I just uploaded this car model to Second Life and it worked fine.


Send me your file and I'll take a look.

[Kitten]

See, now that's the kind of thing I would eventually like to be able to do!

I have sent the file to you. Whenever you get a chance is fine.

Thanks again.

[Andy]

There is a problem in SL with convex polygons. I sliced the top surface (inserted some vertices on the bottom edge, then used Vertex->slice-surface to break the large piece up.

The Second Life image shows your original object on the left and the sliced one on the right. you can see the problem on the left 'shoulder' of the original.


I also tried a triangulated version and that worked OK too. All were imported as Collada .dae files exported from AC3D.



Are you running the latest AC3D and SL-Viewer?

[Kitten]

THANK YOU! At least now I know I have to do more manual work on the models before attempting to upload them in SL. The frustration was real. Much appreciated!