Hey there, having lots of problems with this shape I’m making.
Please take a look at screenshots and blender file.
Everytime I remake the faces around the inner top of the cone, they end up showing a difference of angle. They are right next to one another and should be at same angle. I do see that the vertex normals are different but I can’t seem to get those to align quite right. Maybe thats the problem?
Screenshots: Middle is best version but note detail that at top and bottom of the inside of cone there is vertical divisions where the yellow arrow is! Aaargh. Why can’t I get rid of these?
Then left is reconstruction effort before duping a mirror version to join together. Even here, when I attach the bottom curve vectors to a point, I get a visible change in the shading from faces attached to point vs faces attached to edge inside the cup of the top of the cone.
Other one was old and that was what I was trying to improve on by adding more geometry.
Ok, did that. But it didn’t alter the problem of shading between adjacent faces. Doesn’t affect that normally does it? ALso problem is definitely there, visible in both orthographic and perspectival views, so I would think clipping is unrelated, right?
I think, i misunderstood the problem. Have you tried smooth shading, recalculate normals, merge by distance. Thats what i do when weird shading stuff happens.
The transition on the model to the left is caused by a combination of 2 things:
the edge there is flat shaded. Select the object, apply shade auto-smooth and select an angle where this doesn’t happen.
Faces in the tip area are triangles but they are quads on the sides. This means that the triangles will have a denser geometry and so a different shading.
The middle model uses all quads, which is cleaner, but the quads must have a change of angle at the tip to accomodate the line at the bottom of the hole.
I am not sure exactly what shape you are seeking to make, but are is a way to make it smoother.
I added edge loops to the hole, then used looptools’ relax on them (looptools is an extension that comes with Blender, you just need to enable it, it adds more modeling tools that affect edges). I also set the auto-smooth angle so it would harden only the line at the bottom.
Or is this more like what you seek?
If yes, you must model at a much lower resolution and use subdivision + creases to create the smoothness. The structure inside the hole is a quad grid rather than everything converging to a center line.
Hi, Yes, I’ve recalculated normals. I was looking into split normals but didn’t want special setting on any of the faces as there is a progressive range of faces. Smooth shading doesnt seem to work on these models. Not sure why - maybe my geometry is all messed up but I can’t see why. I have merged by distance. It’s really the places where the ring loop at the crest meets the line in the bottom of the trough. A circle meets a line at a varying angle. thanks for your suggestions
How have you made the object?? Are you working around the origin point of the object as a pivot? Is the Pivot point in the correct position? Like world origin or centre of mass of the object?
Thanks for all of your suggestions here. Thanks for suggesting looptools - this didn’t give me what I wanted but definitely will come in handy elsewhere. Always more to learn!
I realize that i wasn’t as clear about what I am looking for as I could have been. The inside of the little cup does need a hard line across the bottom. One way to look at it is a volcano shape formed by a large 90deg angle that is following the contour of an oval. See screenshot below, please,
So, if I followed the contour of the oval with the much larger triangle, this extrusion would cause a line in the inside of the oval. In fact, I’ve tried to run a profile along the path, but as you might expect it causes a great deal of messy, unfixable intersecting geometry inside the indentation in the oval.
I wonder if this explanation helps you or anyone else to suggest how I might make this shape. I certainly appreciate everyone looking at it.
Hi! I’ve made this shape a number of times. Please see elsewhere in this thread a kind of triangle with a 90deg angle used as a profile to extrude along the oval that is the top of the cone. That didn’t work because it caused a great deal of intersecting geometry.
What I have done here is made a line that should be at the bottom in the indentation and divided it the same number of times as half of the edge of the oval. Then bridge these edge loops and join a mirrored half. This is surely the cause of the visible conflict of shading at that join.
I’m really trying to make a smooth bridge of faces from the oval shape to the produced line within the indentation, or cup at the top of the cone. Hope that is clear, it’s difficult to explain. I certainly appreciate you looking at it.
In this case, I think I know what the problem is. It’s a problem that also affects ordinary cones: they cannot work correctly with smooth shading, you would need the ability to set a single vertex sharp.
The only way to have a 3D mesh of a cone that’s shaded fully correctly is to make the cone with a crazy number of sides (1000 or more) and leave it flat shaded. This is also the only way your mesh could be shaded fully correct, as the hole is really just 2 inverted halves of a cone with some extra geometry in between (so its shading reacts like a cone).
However, it’s also possible to fake it quite convincingly with a subdivided mesh, provided you have the correct set of creases and support edges. This is also easier to work with, as the base mesh doesn’t need as many sides.
I clicked solved and it prompted me not to reply!
I really, really appreciate your elegant and clear solution.
Although I follow what you wrote, some things still confuse me and I would like to ask a bit more.
Did you trace the form I provided or draw a whole new circle/cylinder? I notice the thickness on bottom.
Did you place the line in the bottom of the indent or did it generate from how you made the form?
I grasp the way you explain to use the close support edge loop but notice that you left a few edges out right at the point - was that intentional or a byproduct of your method?
I have experimented with these forms using different drawing methods so many times and never gotten creases or smoothing to do anything. Am I right in assuming you creased only the trough line, oval crest and the bottom “skirt” edge? If you have any advice or tutorials to recommend about creasing and
What is the smooth by angle modifier doing? Because I look at what you did with and without that and its hard to know what it’s doing to me.
I have used blender for a few years but this shows me the importance of elegant, accurate geometry - I had fallen into the weeds of adding more and more. Sorry for so many questions but this solution really helps and also makes me realize that I need to approach things differently.
I remade the model from scratch, it was faster than trying to fix the existing one. When working with subdivision, the base mesh can have fewer sides, which makes it easier to control the shape. I pretty much constructed the hole manually, nothing is auto-generated in my solution.
The edges that are creased should appear purple, so you can know which ones are that way. I manually chose which edges are creased.
The smooth by angle modifier is added when you use “shade auto-smooth”. Auto-smooth has been part of Blender for a long time, but it has recently been changed to be a modifier. The reason it makes little difference is because I used support edges around every creased edge, so their shading was already pretty sharp even before using auto-smooth. I added auto-smooth on top to really make the edges truly sharp, so the model would look exactly like yours. If you disable it, the sharp edges will look like they have a slight bevel, so you can remove it if you prefer that look.
I added some extra edge loops to the sides of the cone because long, thin faces are bad for render performance and shading, especially if they are diagonal (it breaks Cycles’ optimization, which is based on bounding boxes of faces).
Creases are only for when you need an edge to truly be sharp even though you are using subdivision. Usually, you would only use support loops to sharpen an edge and it will leave the corner slightly smooth, which is usually a good thing.
Here is an example of what creases do. I just don’t get why he calls them “bevel weights”, since that’s not what he’s demonstrating here.
Sorry for slow response. Busy times. Thanks for your explanation of the method.
I appreciate that video! I had actually watched that some before, skimmed it sort of, to see how to use the crease. Now I’ve watched it more closely and tried to follow the method.
I want to say that originally I was trying to make these forms with autosmooth. And I did get a bit confused by the switch to this as a modifier. And never quite got something right. So, then I just decided to make a great deal of faces to give them a smoother appearance. But what you made really gives me hope that I can use that method. It is far better.
That said, I have tried to construct this letter. And again, I have something quite wrong with it. Would you take a look? I have added modifiers but it is definitely doing something not as expected. I can say that I’ve carefully joined any overlapping vertices and made sure there were no internal or double faces.
When I turn on the subdiv modifier, some super odd geometry is generated. I can’t for the life of me tell why.
Anyway, thank you so much for your help regardless.
The problem on this one is because of the faces on the bottom side of the letter. Those faces are all N-gons (faces with more than 4 sides) and those don’t subdivide well, both shape-wise and performance-wise. The big one that’s concave is causing the problem you are seeing, because its subdivided form tries to smooth its shape over its own central gap.
The solution is pretty simple. Either you remove those faces if they aren’t needed, or you split them into quads, giving them a similar structure as the top faces.
