(SOLVED!) How to get outline meshes to work in Blender

[ToxicCaves]

Hello! I tried looking around but I haven't found very clear answers about outlines.

Lots of models, especially anime ones, have multiple meshes layered on a model, one intended to be the black cartoon outline and the other to be for cel shading. 

While the cel shading ones work (although seeming a bit too glossy?), I cannot seem get the outline rendered in any way where it doesn't just black out the entire model. I do have limited blender knowledge, but I have fiddled with the materials and whatnot a little bit to no avail. I've also tried blender game/cycles render and it didn't make much difference.

How do I work with or preview the outlines as intended in blender? The file type I'm working with specifically right now are XNALara/XPS files, but I haven't gotten others like .dae files from the models resource to work either.

Here's some previews of what I mean. Model I'm currently using is Vato Falman from FMA Prince of Dawn for Wii; rips provided by RoxasKennedy via another forum.


Texture view with the outline mesh on the outside, appears this way in rendered previews as well.


Outline mesh removed. The cel shading mesh works as mostly intended despite being glossy. Left is material view, right is rendered preview.


closest thing i can get to the outline mesh actually working is being in blender game and using texture preview. material preview blacks it out, and render with f12 is black too.

Here is a screenshot of how the model is supposed to look in-game. Pardon it's a bit low quality



This is probably a silly misunderstanding on my part, but I hope that means it's easy to work with! Thank you for any assistance. I am mostly concerned with the outline, but getting the cel shading to work more as intended would be nice too!

[Makoto]

what i do is duplicate the whole body so u get a total black outline, then invert faces (be aware of zones like eyes or mouth)

[ToxicCaves]

what i do is duplicate the whole body so u get a total black outline, then invert faces (be aware of zones like eyes or mouth)

Hm this isn't making a difference for me with the model. It shows that they did indeed flip, but the outline still previews and renders like a black case around the character.

[Sir Teatei Moonlight]

You're looking for "backface culling". Try starting with this and see where you end up. (Don't forget that the outline object's normals will need to be pointed inwards rather than outwards.)

[ToxicCaves]

You're looking for "backface culling". Try starting with this and see where you end up. (Don't forget that the outline object's normals will need to be pointed inwards rather than outwards.)

this has given me some improvements but not completely there.
In the texture and material previews i have a visible thick outline now around the model :

 
but when rendered it goes completely invisible :
 
i know that link said cycles render, but with that I only get a grey model with less of an outline and more of some weird dark edges. I fiddled with the alpha and colors on the nodes but it didn't change much of anything.
Thanks for the help so far though! Definitely getting somewhere now at least.

[Sir Teatei Moonlight]

The fact that it goes invisible in render suggests you have to disable a box somewhere which always turns faces forward in renders (which defeats the purpose of having them strategically face backward). Unfortunately I don't know where this box is or what it might be called.

[ToxicCaves]

The fact that it goes invisible in render suggests you have to disable a box somewhere which always turns faces forward in renders (which defeats the purpose of having them strategically face backward). Unfortunately I don't know where this box is or what it might be called.

Fixed it!!! The issue was actually in the nodes; the ones in that link were a bit extra. I instead found this and it worked just like that. I feel silly, but glad it's taken care of! And I wouldn't have googled the right question hadn't it been for these responses, so thanks! 

Flip normals -> i dont actually have to use backface culling i dont think for this? i can uncheck the box and it works ->that node output.

Now just look how happy he looks with a working outline