Faces Disappearing between LODs

[spiritLed]

I'm losing my mind over this: Faces on my mesh objects disappearing between LODS and texture changing scripts not applying to every LOD.

Here are screen shots of the objects suffering from this problem (sorry i couldn't figure out how to imbed the images into this message):

High LOD:

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.51.11%20PM_zpscwlmxx6k.png

Problem LOD:

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.51.27%20PM_zps2fmq3ypq.png

Back to normal (at Low LOD):

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.52.00%20PM_zpsitjwwvpo.png

Lowest LOD:

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.51.46%20PM_zpstvlfj6mi.png

 

Wireframe view of issue...

High LOD:

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.52.19%20PM_zps5xsee7fx.png

Weird transition before displaying Medium LOD (missing faces on axe):

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.52.28%20PM_zpskl7uuzae.png

Medium LOD:

http://i622.photobucket.com/albums/tt303/GraphicsCL/Screen%20Shot%202016-07-04%20at%204.52.36%20PM_zpskwjnlrbt.png

 

All the faces look fine inside Blender, and look fine in the Firestorm mesh uploader.

it only affects one side of the mesh. Help would be greatly appreciated, thanks

[ChinRey]

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spiritLed wrote:

it only affects one side of the mesh.

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I think that's the clue.

Am I right in assuming you use LOD models generated by the uploader? The algorithm used there is a rather crude mesh butchering device called GLOD (Geometric Level Of Detail). It's not a proper simplification tool at all, the only thing it does is remove polys and when it does that, its first priority is to retain at least one tri for each face, second priority to keep the overall size of the object, third priority to retain the outline. In this case that means it's quite hapy to delete all the tris for a face on one side as long as there is at least one on the other side of the item.

You can compensate by increasing the number of triangles in the LOD models of course but, really: don't use that function at all. Create your LOD models in Blender instead. Ideally, you do them manually but even if you don't feel up to that task, Blender has to fairly decent autosiplification tools, limited dissolve and the decimate modifier, that both do a far better job than GLOD.

[spiritLed]

So glad to hear from you. I created each level of detail in blender, the lod created by the viewer was not up to my standards

 

[Codex Alpha]

Please ensure that you have the normals on those faces pointed the right way. Notice on the wireframe how the faces aren't showing.

Edit Mode, hit N go to Mesh Display -> Normals-> Select the Face option to see the lines.

This can happen if you used "Solidify" modifier or extruded a different way than you expected and the normals on the faces flipped for some reason.

If you did not ensure this on the original mesh, then your LODs will follow suit.

[ChinRey]

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spiritLed wrote:

I created each level of detail in blender, the lod created by the viewer was not up to my standards

 

---

 

I was going to post the next possible explanation but entity0x beat me to it. Flip them normals and all should be fine.

One additional tip: the Normal pointers in Blender can be a bit confusing when you have several srufaces close to each other. Sometimes you may also want to check by switching on backface culling (it's in the Shading section) right above the Mesh Display section).

[spiritLed]

anyway that i can send you the blender file to look at? the normals all seems okay to me.

[spiritLed]

uploaded the same dae files to inworldz and i dont seem to have the same issue with disappearing faces. in both cases im using the latest Firestom to upload and view. I did try uploading to SL with the SL viewer and same issue with the faces.

[arton Rotaru]

You can send me the blend file if you like, and I'll take a look. Check your private messages here for my email addy.