Flipping Normals or Retriangulating my messed up model

[hydrag]

Hi,

While our project is close to being finished, I'm currently stuck with a massive problem. As we were modelling everything in the line view mode, we never cared for surface normals. When I then switched to the default shading
everything was basically black:

So I converted it to a poly/mesh and chose the faces and flipped the normals to end up with this. And as you can see from the render it shows up as surface:

So I exported this model into Substance Painter to make the final texture when I noticed something. I already noticed that when I did it for the whole model without flipping some of the normals.

Although the material is black, or chrome, or whatever, it will always have this golden hue, once I apply the map. For the final model it was like this, some parts where black and some where golden, so there is a difference in how substance painter treats these surfaces. And if you look for the UV map, it's the same in 3ds Max, it's basically a lot of triangles, seperated.

When I turn it upside down however you can see the actual color of the model:

Now I'm a bit lost here. The parts are .FBX files in the end and the textures will be applied to those inside a PC game. When I export them into the game I can see the same effect, some parts are colored correctly, some a black (probably normals not flipped) and some are golden. So it's not only substance painter, but it's how the map is created.

Now I'm stuck with this and some other parts and I have no idea how to repair them. As you can see, some of the parts seem strechted. I already solved this in an earlier attempt by connecting more points to create some support points for the texture. I tried to export it and re-import it with new triangles but it messed up the structure in the end.

As you can see from the wires, it is a quite complicated structure:

We started from a box and then added more and more connect lines and stretched them along different side views of the original model. It looks somewhat okay for the quality of our model but it's of course not the best solution. During that process we might have ended up in dragging things through each other although it doesn't look like that from the default shading...

Is there a way to perhaps delete all those weird connections and reconnect them or how would you save that model here? I tried to conform a plane onto the shape but it chooses one point somewhere along the curve and pulls it weirdly onto the model. I'm a bit lost here since the model itself is pretty okay to us, we'd only require a texture and perhaps some smoothing on the edges.

For those who want to give it a try I will also upload the model. Any help is welcome here.

Thank you all in advance!

[10DSpace · Accepted solution]

@hydrag 

You have 2 issues here:

1. Use of mirror causes negative scaling (see image below).  Simple fix is to Reset Xform from the Utilities Panel (Reset Xform>reset selected and then (also in Utilities panel) Collapse>Collapse selected.  You will see that after this the scaling has been reset to all (positive) 100%.  You will also see that your mesh in this case is no longer all black but has the surface displayed correctly. 

2. Uvs not properly set up  Currently your Uvs are all overlapping which means that multiple areas of the mesh share the same UV space.  So painting in Substance Painter will result in the strokes appearing at multiple places at once which is usually not what you want.  Simple Fix is to do the UVs properly which with this simple mesh is pretty easy by using flatten mapping (default of 45 degrees is fine for your mesh) from the tools menu of the UV Editor window.  See shots below.

After the above steps export the corrected model via .fbx and it should work properly in Substance Painter.

[hydrag]

Thank you so much for your fast answer!

It worked! But, how could I perhaps re-triangulate those sides with the larger triangles? I connected more lines into it but Substance Painter would still see them a bigger. So when I apply let's say carbon fiber you can see bigger and smaller squares. I onced managed to solve this with the Patch but I can't seem to be able to recreate it now...

[10DSpace]

@hydrag 

But, how could I perhaps re-triangulate those sides with the larger triangles? 

Make sure your model has been converted to an editable poly and then in the Modeling ribbon choose the Modeling tab > Geometry All dropdown > , then "Quadrify All".  This will remove all of the diagonals on the sides (i.e., making quads) except 1 in your case.  For the remaining diagonal just select it and hit the backspace key  (shortcut for remove).  In your case, you should also select the polygons that contained the diagonals and in the smoothing groups section of the EP rollout, choose "clear all" and then "Auto Smooth" since the diagonals had previously deformed the surface a little.