Mesh normals broken along UV seam in-game...

[Archangel35757]

@@DT85, @@AshuraDX, @@Psyk0Sith, @@Xycaleth and any others...

 

I had a long chat with AshuraDX today about this issue and I'd like thread to serve as the forum to discuss and resolve this issue.

 

For example, is this caused by Carcass or is it caused by the dotXSI exporter? So these broken normals along UV seams show up in the dotXSI files in the XSIViewer or Softimage ModTool? If not then it's definitely Carcass and we can get it fixed by a little black birdie

 

@@DT85 @@AshuraDX please post screenshots

[DT.]

Carcass. Unless you use -smooth option, you will have splits. HOWEVER, this also will weld any predefined splits you want.

 

I performed a test for AshuraDX in Noesis with one of his models that he did crazy normal stuff to and managed to have no split in-game. So if you don't want any mesh splits and/or you want to control your mesh splits, use Noesis to convert to GLM and not carcass. This will be great for rend2 as well, as you can get rid of the visual splits between mesh parts. AshuraDX is a very clever monkey.

[minilogoguy18]

I'd rather have carcass fixed, it's tired and true, so many tutorials and every time I used Noesis as a intermediate program I had problems.

 

Does the -smooth option only weld boundary points/edges that share the same EXACT global coordinates? Or will it try to weld a boundary edge to the nearest surface?

[DT.]

It visually welds any points that are in the same position, including mesh part splits. I'm thinking it's operating on the normals, not the verts themselves so nothing is welded together physically.

[Archangel35757]

It visually welds any points that are in the same position, including mesh part splits. I'm thinking it's operating on the normals, not the verts themselves so nothing is welded together physically.

But are those normal vector splits already present in the dotXSI file and just passed along to Carcass? I need to go back and review...

 

@@minilogoguy18 -- Carcass can be fixed... if that's the only source of problem.

[DT.]

We checked this ages ago, and the dotXSI file didn't have the splits. Too bad Raven didn't put in a conversion from GLM back to dotXSI, that would be so handy...

[Archangel35757]

@@DT85 -- so it seems (pun intended) that I need to "request" Raven to modify the -smooth command option... and create a switch option for "smoothUVSeams"

 

The -smoothUVseams would only affect UV seams and we could keep hard edges then by not using -smooth switch.

[Archangel35757]

 

First image shows the inner part of the thumb which you can see the texture seam where it isn't quite perfect, the vertexes are all welded along that seam. The second image I disconnected and you can see the vertex normal lines now making "V's" from there being 2 vertexes sharing the same space and having different normals. Now, it's hard to see but in the third image you can see that the vertex's along the seam share a common normal.

 

After further inspection carcass is responsible for splitting edges along UV boundaries BUT for some reason my normals are being preserved so that the seam isn't noticeable but I saw the telltale vertex count increase in ModView which means my edges are getting split BUT it's not affecting the normals. Need to dig more but this could also mean that for whatever reason I may be able to work with custom normals where you guys it seems to be ignored when you use your smoothing groups.

 

EDIT: I'm also just kinda guessing that my edges are getting split along UV boundaries based on the increased vertex count but wouldn't know for sure unless someone imported the GLM file, the dotXSI file has no splits when I import it.

So @@minilogoguy18 did the above test in Softimage...

 

...why would Carcass split the mesh along UV seams? @@DT85, @@Psyk0Sith, @@Xycaleth? ??

[mrwonko]

...why would Carcass split the mesh along UV seams?

Because a vertex in glm can only have one UV coordinate.

[Archangel35757]

Because a vertex in glm can only have one UV coordinate.

So there is no "fix" for that since it's inherent in the GLM format. Best you can do is ensure the normals at that UV boundary are identical. Correct?

[mrwonko]

So there is no "fix" form that since it's inherent inthe GLM format. Best you can do is ensure the normals at that UV boundary are identical. Correct?

Correct, that would be the fix.

[DT.]

Well the -smooth switch in Carcass unifies all normals, no matter if there's mesh breaks but no one wants their entire model smooth unless it's for rend2 lol. So this is what I see needs to happen:

 

- The Max exporter needs to be fixed to allow custom normals, I've verified that carcass reads custom normals from the dotXSI files from Mod Tool.

- Need a Maxscript to auto-break the mesh along UV seams so we can use custom normals to smooth out the appearance and hope to shit that carcass will apply the custom normals AFTER it wants to break the model at the UV seams.

[Archangel35757]

Well the -smooth switch in Carcass unifies all normals, no matter if there's mesh breaks but no one wants their entire model smooth unless it's for rend2 lol. So this is what I see needs to happen:

 

- The Max exporter needs to be fixed to allow custom normals, I've verified that carcass reads custom normals from the dotXSI files from Mod Tool.

- Need a Maxscript to auto-break the mesh along UV seams so we can use custom normals to smooth out the appearance and hope to shit that carcass will apply the custom normals AFTER it wants to break the model at the UV seams.

According to @@minilogoguy18 Carcass already unifies the normals along the UV seams where it inserts duplicate verts (per @@mrwonko)... so I think that all that needs to happen is for me to fix the vertex normals exporting in the dotXSI exporter. No -smooth switch needed. I'll get crackin' on this tomorrow and hopefully will have a beta v1.9 for you to test this weekend.

[minilogoguy18]

Yeah, I am getting splits in the GLM BUT the normals match along the seams making it very hard to see but I'm sure under certain conditions it may be noticed but you'd really have to be looking for it.

 

On my end the dotXSI file isn't split along the UV boundaries.

 

@@Archangel35757, if you can have carcass modified by someone then I like DT85's idea, see if we can get the compiler to run in reverse.

[Psyk0Sith]

So @@minilogoguy18 did the above test in Softimage...

 

...why would Carcass split the mesh along UV seams? @@DT85, @@Psyk0Sith, @@Xycaleth? ??

Read The part "Welcome to splitville"

 

http://www.ericchadwick.com/examples/provost/byf2.html

 

And then...

 

http://www.polycount.com/forum/showpost.php?p=767368&postcount=64

[Archangel35757]

Like @@mrwonko said, in the GLM format a vert can have only one UV texture coordinate... if you split the mesh along UV seams inside 3dsMax before exporting... then Carcass should not add any new verts along the UV seams. I think only the 3dsMax exporter needs fixing.

[Psyk0Sith]

That's right, only 1 per vertex BUT when uv mapped you create a NEW vert. So there's 2. Same goes for smoothing groups or custom normals.

 

- Need a Maxscript to auto-break the mesh along UV seams so we can use custom normals to smooth out the appearance and hope to shit that carcass will apply the custom normals AFTER it wants to break the model at the UV seams.

 

It already exists in textools for that exact purpose! \m/