Blender export problems "no object selected"

[AlexGJacobs]

I am using Blender 2.78 and running under MAC OS.

I am having sporadic issues of not being able to export to Collada using the presets for SL static mesh.  I created an object, it happens to be an arched window.  I created the first object, did an unwrap and produced the UV map.  I successfully created the three faces that I wanted.  I then used array to create and offset the second part of the window.  I selected the object in edit mode, with the UV Map, selected export and then used the SL+OpenSim Static presets.  I get the warning....."No objects selected - created empty export file"

In an attempt to troubleshoot this, I tried the export but this time I selected the contents on the SL_OpenSim Static presets one at a time and it would export until I selected under texture options "Only Selected UV Map".  Once I do that, the export fails.  

 

If somebody can help or needs to look at the file, I would happily provide it.  This is on the verge of driving me crazy.  Thanks for any assistance.  

[ChinRey]

2 hours ago, AlexGJacobs said:

In an attempt to troubleshoot this, I tried the export but this time I selected the contents on the SL_OpenSim Static presets one at a time and it would export until I selected under texture options "Only Selected UV Map".  Once I do that, the export fails. 

Seems the answer is fairly obvious: don't check the "Only Selected UV Map" checkbox.

Edit: The only selected UV map function does exactly what it says, it allows you to export only polys assigned to a specific UV map. But when you're building for SL you really, really, really don't want to have more than a single UV map in your Blender file anyway so in this context, that checkbox is superfluous at best.

I have honestly no idea what the SL+OpenSim Static preset is. I've exported thousands of meshes from Blender to SL and this is the firsttime I've even heard of it. But to export to SL, you may or may not want to export Selection Only, you may or may not want to include textures and if you've been careful with how you've configured the polys you don't want Blender to triangulate on export.

Edited July 13, 2017 by ChinRey

[AlexGJacobs]

Thank you.....the added explanation makes it way more obvious.  I did not really understand exactly what that checkbox does.  

 

I appreciate your help.  

[ChinRey]

5 minutes ago, AlexGJacobs said:

Thank you....

YW. I added a bit more just as you replied. Had a look at that SL/OpenSim preset and... ummm... that's not the settings I would recommend.

Edited July 13, 2017 by ChinRey

[AlexGJacobs]

If you don't mind my asking, what settings would you recommend? ....other than not using the one in question.

Edited July 13, 2017 by AlexGJacobs

[ChinRey]

8 hours ago, AlexGJacobs said:

If you don't mind my asking, what settings would you recommend? ....other than not using the one in question.

I suppose others have different answers here. One important thing about Blender is that it's very flexible and different people use it in very different ways but:

• Apply modifiers - it's probably no point in switching that on since it's likely you have already applied modifiers before exporting to better see the end resultin Blender.
• Selection Only: It depends. If your Blender file only has a single object, it doesn't matter if it's on or off. If the file has several objects and you only want to export one of them, keep that option off, if you want to export several obejcts in one batch, keep it on. Personally I never export multiple objects together. I prefer to export one part at a time and assemble inworld since I find it easier to keep track of all the LoD and physcis models that way. That's jsut my work method though and not necessarily what suits everybody else.
• Only Selected UV Map: Play it safe and make sure there is only one UV map right from the start. Second Life can get really funky when asked to handle meshes with multiple UV maps and it's easy to loose track of which poly is assigned to which UV map throughout the modelling process.
• Include UV Textures / Include Material Textures: If you want to include the textures in the same upload as the mesh, you want to switch one of those on. I'm not sure which since I never do it that way myself. Even when I use Blender for textures, I always edit them in a image editor and import them separately. It's probably the UV Textures you want to include but others can answer that better than me.
• Copy: No idea what it does to be honest. Keep it switched on.
• Armature Options: Those are for rigged mesh only.
• Triangulate: That's a tricky one. Ideally you want it switched off but sometimes that gives distorted meshes.
• The rest of the options: Just keep them at default.

[AlexGJacobs]

Thank you very much.   New to building and new to Blender.  A dangerous combination!!!  

[Drongle McMahon]

I just want to add a point about the option(s) for including textures in the mesh upload (ass opposed to uploading them separately and applying them inworld). I have used a lot of re-usable (usually seamless) textures on many different items. This has the advantage of minimizing the texture downloading lag where the texture is used on multiple items in a location. Each time you upload the exact same texture with a different (or the same) mesh, however, the system treats it as a completely separate texture. Thus it receives a new ID, occupies a new slot in the asset database, and has to be downloaded repeatedly by all viewers seeing it on multiple items, even when the same texture with a different ID is already in the cache. The duplicated textures are also added to your inventory, in places you may have difficulty finding. These effects happens whether you are re-using a general purpose texture or simply uploading a mesh after some non-texture alterations. So, unless you never re-use a texture, uploading textures with the mesh always causes unnecessary duplication and consequent waste of resources. That's why I have always advised against it. There are also some minor problems often encountered by beginners in the course of uploading textures with the mesh.