ReImporting Mesh Errors

[Psynema]

HELP I've exploded a mesh of an oven for baking and so I can see the inside while I paint. I then switched it out to a collapsed model to paint more details but now my texture isn't synching with the model and the UVs are exactly the same.
Further infuriating as it's completely fine in Houdini - the textures display just fine in exploded and collapsed modes. Substance seems like it's pulling a new UV layout from out of nowhere.

I've heard the pivot/bounding box are issues but tried having the same pivot and no effect and I've done this before in Painter - ie changing topology, exploding then collapsing meshes, sans problem.

REALLY EXTRA INFURIATING - when I switch from exploded to collapsed version of the model, it displays PERFECTLY....then the red loading bar happens...then it goes to hell.

WTF is going on? I've had this issue before with Blender and never figured it out - also modelling an oven...WTF.
Anyone have any ideas? Is substance painter ignoring the UV layout and doing some odd projection of sorts?

[Vincent Gault]

Hey, sadly this is normal, as SP is reprojecting your brush strokes in the space where you painted them (mostly the 3d view I assume). Therefore if you modify the shape of your asset, the reprojection will be broken.
So the shape has to remain the same when you re-import an asset.

[Psynema]

Thanks - confusing as I've done it before sans problem. 

Really don't understand why it won't work when I flatten the textures given the UVs are the same as well but displays the textures just fine for a brief period of time before reloading...there's no way to get the info from UVs only?  I see the model is fine right after reimporting but then the red loading bar starts up then it goes astray....I'll avoid Painter I suppose as I'd have to see inside certain hard to reach crevices etc. 

But is there really no way to get it out of painter as is and onto the collapsed model?  It displays fine in Houdini but I don't understand why it won't display the textures AFTER EXPORTING THEM given the UVs are flat and not projected post exporting.  Marmoset and sketchfab were displaying them improperly but Houdini displays them fine...I'm so confused why the UVs aren't good enough AFTER exporting.  I mean models move and change parts all the time and the last time this happened to me Sketchfab and Blender displayed the textures after exporting just fine after I changed the topology.  Je ne comprend pas

[Vincent Gault]

The only way you could do it would be to export your maps from your old mesh, then reapply it to your new mesh

[Psynema]

Tried that doesn't work oddly enough as it still going by projection even after exporting. 

[Vincent Gault]

yes, but the idea would be to create a new scen (not to reimport your mesh

[Psynema]

That's exactly what I mean, when I import the new mesh and apply the exploded materials, in a NEW SCENE and IN EXTERNAL PROGRAMS ASIDE from substance...it's out of synch and messed up and I have no clue why as the UVs are both identical. 

Houdini recognizes the new model and displays appropriately.  No clue why this is happening...argh.