Smoothing Group Issues - Evil black shading!

LuckyNinja

Hey there, recently been making a new model, gotten to the low-poly modelling, everything has been going kosher until I got to the smoothing. I've got a lot of shading issues going on, on a few of the elements, and I can't quite figure out why.



Looks pretty ugly, right? Thing is, I've tried going over as many tutorials and previous cases here on the forum, and what-not, but regarding the fixes recommended, no dice.



I've avoided 90deg angles for the areas shaded, I've kept a roughly smooth topology flow, and there's few elongated quads (and thus, triangles)



Here shows the different shading groups used in this. Removing some of the faces from the smoothing group, however, does nothing to stop the issue, and most of the faces are aligned perfectly along the z-axis


Any help would be greatly appreciated, thank you!

Bartalon

Does that blue smoothing group continue all the way underneath the object?

RedRogueXIII

Normals are being unevenly skewed between the flat and curved sections of the shape.

Short story fix : add another edge loop on the flat side along the curve for the top and bottom. This will add an even shading transition between the flat and curve.

s6

RedRogueXIII wrote: »

Normals are being unevenly skewed between the flat and curved sections of the shape.

Short story fix : add another edge loop on the flat side along the curve for the top and bottom. This will add an even shading transition between the flat and curve.

This. You could also add more segments to the curve under the grip so the angle the smoothing is trying to average is less extreme.

One more possibility it to put the entire side portion on its own smoothing group.

LuckyNinja

Okay Redrogue, I attempted what you suggested, adding edge loops as if I were making hard lines on a high poly, and it appears to have mostly fixed it, although there is now some 'hard' lighting differences on what should be a curved surface

So, what's the theory behind this that means that edge loops fix the issues (any tutorials etc). and are there any possible workarounds that are less polycount-intensive (my model is currently well under my budget, but it would be handy for future reference)

Quack!

LuckyNinja wrote: »

Okay Redrogue, I attempted what you suggested, adding edge loops as if I were making hard lines on a high poly, and it appears to have mostly fixed it, although there is now some 'hard' lighting differences on what should be a curved surface

So, what's the theory behind this that means that edge loops fix the issues (any tutorials etc). and are there any possible workarounds that are less polycount-intensive (my model is currently well under my budget, but it would be handy for future reference)

You have two options, create the curve using geo or use a normal map baked from a high poly model to fake the curved edge.

Typically, with modern engines, you would bake from a high poly model, but if you can't, you just need to throw triangles at it until you get the smoothing and shape you want.

LuckyNinja

Hey all, back again, I thought I had fixed the issues with the shading groups. Hoo boy was I wrong. If anything, the problem has gotten worse. See, I finally did the normal map bake, and this is the result that I got.

(ignore the normal screw up on the underside, that's just a curious side effect of using xnormal - the problem areound the rest persists, and is virtually identical, regardless of which program is used to generate the map).

Compared to non-mapped you could argue that the non-mapped actually looks smoother. Obviously, non-mapped the lighting still makes it look a bit bad, so I would quite like for the part to actually curve. Here is an overlay (apologise for the quality) of the low-poly an the high-poly

Interestingly, I've also gotten seam issues on hard edges between smoothing groups despite separating every smoothing group into UV islands and padding the edges.

I have read the 'Making Me Hard' thread on normal maps, following it's advice to try for 'B', and I am pretty sure that I haven't missed anything out.

Any help would be greatly appreciated, as I cannot figure out for the life of me why everything looks so crap, and I'm desperate to have at least one, finished, quality 3d model.

Many thanks!