Wes, since LN introduced the muscle definition slider, we've had problems with weird seams in altered clothing meshes that show nude skin. The most noticeable I've seen is along the inner left leg of the male bottom, as in this manly bulge mesh:



This is a mismatch in the muscle definition bumpmap, since it only appears when the slider is used. Bloom identified the problem as happening after import/export with Milkshape. I took a look at the data and found the tangents were altered after import/export. When I tried copying the original tangent values from the EA mesh to the altered mesh, that fixed the seam and everything looks fine.

I don't know what the tangents are supposed to do... both your plugins and TSRW's are doing this according to Bloom so maybe there's a reason for it. Anyway, could you take a look when you have a chance and see if this could be fixed in an update of your import/export plugins? If you can, thanks so much!

I haven't got a clue what LN is, or the muscle slider. Or what mesh goes wrong.

I see the seam, and I know what tangents are. But I have no files to work the issue with.

<* Wes *>

Sorry! LN = Late Night, which introduced a muscle definition slider which overlays a bumpmap on the skin texture used for clothing meshes to give the effect of shadowed muscles.

I've attached the original EA swimsuit mesh, and the mesh in the pic above which was altered in Milkshape by moving a few vertices, so you can see the before and after tangent values.

Thanks!

Any progress on this?

What I did in the meantime is copy the tangents from the EA original mesh to my modified mesh, which works well if you haven't added or removed verts. Here's the program if you want it. It's not very polished, but use the Mesh Tools / Mesh Copier function.

Thank you

It is strange that the vertId's are listen under tangent/normals in Delphy's GEOM editor, not?

edit,
hmm, i was able to fix a custom bottom.
When inspecting the vertice on the seam between the tail and other bottoms i noticed the UV's had a very small mismatch.
After correcting these the whole seam got fixed.
I used extended manual edit wich is included in Demon's alligne normals plugin(to compare)
Unfortunate the uv's seem correct on the male bottoms.

edit,
nm, all seems irrelevant

I have this problem with my modified meshes as well. This is the first I've heard of tangents. How can I view the tangents in Milkshape to verify they are incorrect? I don't see any entries in the Manual Extended Editor or menu items that mention tangents.

i was wrong, i first thought it were the uv's but those only fixed the seam between tops and bottoms(wich was a mistake made by myself), not the issues on the inner thigh.

According to Cmar the tangents get changed on export(or maybe import?)

I don't think the tangents are used in Milkshape at all - in which case I would think they need to be stored on input of the mesh and exported back out unchanged, unless the exporter can recalculate them. Can't tell if the glitch is happening on import or export.

I finally got around to confirming with MeshToolKit that the seam mismatch I'm seeing on the right side of the tops is indeed caused by the tangent issue. It seemed to work well using the first Vertex Order option, was that the correct option to use, or should I have gone with Vertex ID?

I don't quite understand what tangents are, but I've read they're calculated from the normals. Wouldn't that mean a mesh created from scratch would have seam problems unless its tangents are also correct? I'd think that would mean the exporter needs to recalculate them because a mesh from scratch wouldn't have any original tangents to copy from.

The Vertex Order and Vertex ID options are both fine if all you've done is move verts. If you've added or removed verts you need to use Vertex ID. If you've renumbered verts you need to use Vertex Order. If you did both at the same time you're up the creek.

I don't really understand tangents myself except that, as you said, they can be calculated.

it is also possible that they use the same methode as with object normalmaps, repositioning the uvcoordinates?

Cmar, did you overwrite your GEOM when saving or did you rename and save?
The plugins do not always save a GEOM correct when overwriting.(like meshcomments and such)

I fixed the mermaid seam on the waist but after another edit on it in Milkshape i lost the correct uv''s again, so something is wrong there also.

I usually save as a new file when working with geoms so I still have the EA original available. I've never seen a problem when overwriting, though.

But how does it work when vertex are removed or added ?

<strike>I think you'll just get tangents of zero, which may not look too good - don't remember exactly what the tool is designed to do at the moment, and I'm in the process of rewriting it. The real fix would be to calculate/recalculate the tangents, but I don't yet understand the math involved.</strike>

Edit: The tool copies the data it can find in the original mesh. If vertices have been added, it leaves them with the tangents Milkshape (I assume) has calculated for them. I don't know if I'm ever going to be able to programmatically calculate correct tangents for meshes - the math is really beyond me and possibly EA uses some kind of non-standard method which is why we're having this problem in the first place.

Much later edit: I found a tangent calculation which works well, and was added to Toolkit some time ago. TSRW is also using it.