Been doing tons of research and have been finding out all kinds of stuff.
I found something pretty great. For me personally I don’t like toon shaders, they are stuck in this limbo where they are cartoony looking but you can still tell its a 3d object with a shader. Same thing with fake outlines either free styles or the inverted trick. But I didn’t really know why, like I can’t put into words why it doesn’t work.
But I found this combined with something DavidRivera said it makes sense to me now.
The toon shaders most commonly used in Blender just don’t look organic enough and look too calculated. Same thing with free style lines they are too perfect. I think a big key to getting a 2.5D style down is to find ways to fake imperfections with how the character is shaded, moves, and is outlined.
Ive been messing around with some shader set ups and found a way to have non lit areas project a single solid color and lit areas project a texture which is colored based on how much light is hitting it. I used a Japanese sumi e to give sort of a live painting effect. Its not that great right now but im gonna keep messing with the node set up to see where it goes
Its not just that the texture is too dark to see it works with any color. With the Monkey on the left the solid black parts are with low or no light hitting and it goes all the way up to green where light source is almost touching it. Its not actually being effected by the worlds light you can change the lights color or even add volumetric lighting and it will be the same colors. The shader is actually shadless and its seeing what is and isn’t lit.
Here you can see it on a flat plane. Here it goes from black to red, black being no light red when its extremely lit. It makes a pretty cool effect kind of like the Japanese rising sun blocked by clouds that can be used as a sky box. The red sun is simply generated with a point light really close to the object and coloring that part of the texture red.
The only thing I did was move the light to the right
Im gonna fiddle around with this. I think this could be a good way to make textured shadows. For example you texture a character in their lit state then re texture them with darker colors almost like a mask layer. If anyone wants to play around with this that would be great!