Shading Issue (Curve Modifier Bezier)


what’s the issue with the lighting is this situation?

I applied a curve modifier to the right-side shape and deformed it using a bezier curve, into the left-side shape. but i’m getting this weird lighting issue.

anyone knows why? i selected some random edge vertices (on the same edge ) of the curved shape to check their z position to see if maybe the edges were titled, but found just a few with 0.0001 difference (or somewhere along those numbers) between them and i don’t believe that’s the issue.

i’ve also added vertical edge loops to increase the face count on both objects, but yields the same exact visual result.

also, i’ve had no issues with a sphere, so i can only assume it’s a result of the curve modifier following the bezier that’s causing the issue.

what can i do to fix this? (if anything)

Hi! Is the object shaded as Smooth, AutoSmooth or Flat?

oh, i forgot about that.

it’s flat.

this is how it looks with Smooth

and this with Auto Smooth

Hmmm, still lookst kinda weird :face_with_raised_eyebrow: It’s hard to say what exactly is going on judging by the image alone…
Maybe the resolution of the curve is too low?

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i ramped the resolution of the curve to the max.

i read that his modifier isnt the easiest to work with and by the experience i had with it it is true.

maybe this is one of the examples of that. although i acheived the result shape by tinkering with the settings what remains is a bunch of weirdness.

oh,btw, although i started with a bezeir curve, i deleted the original two vertices and added four with the draw tool (i think its called). i dont know if that would make a difference.

I’ve also checked for double verts and faces are oriented correctly outside…

ps. i’ve attached the blend file, if anyone could take a look
bezier.blend (1.0 MB)

Default resolution (12) should be fine probably. It’s the number of segments between two points of the curve - more segments mean smoother curve. But of course the resolution of the mesh matters as well.

I don’t really see as much distortion in the file as in screenshots above now - it’s not perfect but seems reasonable :thinking:

it’s odd that you don’t see as much deformation…

why it isn’t perfect is still the issue, though.

i mean, i think it should be.

Why all the edges? So close together in the center…
Here is one with a subdivided plane Curve Modifier, Subdivision Surface, and a Solidify
Shade auto Smooth…Resolution 12, curve subdivided 2x’s and smoothed…


the reason for the weird geo is that i want to cut out a shape through the curved object with a boolean.

i did that, and the shading looked weird around the edges of the cut, so i added loop cuts.
it looks almost good (with a couple fixes to be made in the top and bottom of the cut-out).

but there’s still some weird shading issues near the top and bottom of the cut-out.

so i’m testing to see how i can get the least geometry and make it look good, without much clean up.

so i thought i’d start with the cut out shape itself, duplicate and extrude vertices until i got the shape we see in the picture below.
hence the weird geo.

now i’m using a new mesh with “normal” geometry, with the same bezier curve as i’ve been using and it’s getting really messed up because of the bezier curve.

edit: ok, the twisting is because of the twist method on the bezier’s properties.
and i think the weird shading in the first image is because of the bezier’s transformations weren’t applied.

auto smoothed:

does that look good? or like it should look?

When you cut that with the boolean, all of those edges are going to produce artifacts along the edge of the cut…Long skinny faces tend to do that…that is why you hear Quads all the time…

Better to use a standard plane with a few subdivisions. Then start adding your Modifiers…

Hi there,

I guess you just need to do some work with lighting rather than with the material. There’s a tons of yt tutorials out there on how to make a realistic lighting etc.

Here’s a few of them:

Blockquote all of those edges are going to produce artifacts along the edge of the cut

you mean like these edge artifacts,right? (this is the first thing i tried; a subdivided shape with the boolean and it gave me a shit ton of those artifacts)

if so, then, this is why i used the cutout and extruded from it to make the final square shape.

this way everything is a quad.

but still, i have to deal with the skinny edges, which also produce those artifacts you say? i have to deal with those? (thanks btw for your assistance)

(i understand you’re saying there’s a better way to do things, but the way i did it gives me better results, aka, no tris and much less artifacts along the edges of the cutout…)

what’s the difference between using a light as opposed to the mat cap, to see what’s going on with the geometry? i don’t see any. i guess you’re saying as a better way to see how the geometry would look in the real world.
oki doke.

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As far as the skinny faces I was thinking more along the lines of texturing artifacts and stretching… and there are so many of them in that area…
I didn’t realize you were doing something with extrude…

Here is what I did to your mesh…
I added a circle-shaped heart…
I then dissolved about 20% of the edges in the area, to stop some hot-lining…

Boolean Difference with Booltool…( fixing the edges with edge-slide ) and deleting a good percentage of them…

added smooth twice as well as Laplacian Smooth…
And used the Knife Tool to cut a support loop around the whole ( messed up a bit as I forgot snapping was on, but it didn’t hurt anything so left the bottom join to the edge loop…)

A subdivision on your curve would get rid of the shadow on the curved section on the bottom of the hole…just tweak the curve some more…

bezier-002.blend (1.1 MB)


looks good.
it seems we’ll always have to compromise between the amount of geometry versus the weird shading. and tris, and quads. and n-gons. man! but i learned something. those thin lines were messing up the shading. so, getting rid of those makes the shading look much smoother.


This is probably the most important bit if you want to use subd – hard edges need to be supported.

If you use booleans, it really helps to plan ahead (have similar vertex count for both objects) and put main support loops in before doing the bool, so Blender creates decent topo on its own and you have less to clean up. I have this guy, FrankPolygon, bookmarked; he’s a wizard with hard surface modeling. He has a bunch of exercises for using booleans so you don’t get an unholy mess.

There’s no reason not to use matcaps; that’s in part what they’re there for. The one you’re using is my favourite for this sort of thing.

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Blockquote This is probably the most important bit if you want to use subd – hard edges need to be supported.

yep, loop cuts or even the knife tool helps. i’ve seen this used on the blender bros channel to fix some shading issues.

i just wanted to try and see if i could make this shape without cutting into the geometry and get the bunch of ngons and having to fix the bunch of shading issues. (maybe im doing it wrong but i’m learning the ropes as i go along)

thanks for suggesting FrankPolygon - it’s seems to be a very good place to get some basics!

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