UV-unwrapping a cone

[anselm Hexicola]

For the best results when applying textures, which layout gives the best results in general?

Here is a section of a cone:-



Here is what Blender gives as a UV map ( the seams having been marked as seen above) :-

But, really I would prefer this

[anselm Hexicola]

Not familiar with the new way of adding images, so my post was truncated.

(Here is the rest of what I THOUGHT I had posted.),

Below is what I would prefer:-



Admittedly there IS squashing of the outer-most faces, but I prefer this general arrangement because the Top and Bottom edges are on the same respective y-axis position. ( Thought being that it makes more sense for Texture application.)

As usual, I am just trying things out; I have no depth in 3-D modelling, but would welcome other's tips and advice.

[Rolig Loon]

You can go one better than your second version.  Unwrap your conical section, then select one of the faces and align its edges in the UV map with the X and Y axes, so that it's a rectangle instead of a trapezoid.  Then select all faces and unwrap a second time, using the Follow Active Quads option.  You'll get a map that looks like this:



[Devriv]

You can also use cylinder projection (it would be my first choice) and you will not need to add a seam.

[anselm Hexicola]

Yes, that "Follow Active Quad"  option is a great time-saver; I started using it a few months back - wish I had learnt to use it 2 years ago!

Anyway, your unwrap has the virtue of tidy tiling, but it will still necessarily give distortions of scale with texture.

I tried to do another version of my "scaled" unwrap:-



It preserves scale but of course does not tile.

I applied an (albeit fuzzy) honeycomb texture to 3 cone sections:-

On this view, No.2 has the b

[anselm Hexicola]

( not having much luck with Forum posts atm - they seem to get truncated at some random point.)

The continuation of the post above is, as follows :-

 On this view, No.2 has the best result.

BUT, look round the back.



Ughh! Back to the drawing-board ...

 

[IvanBenjammin]

You're either going to have a seam, or you're going to have distortion, there's no third option without either (unless you want to talk about 3d painting and/or baking of textures ) 

I would personally go with Rollig's version, because a) I prefer a little distortion over seams, and b) its a more efficient use of UV space, which means less texture waste.

It's also worth bearing in mind that  distortion will be more or less of a problem depending on the type of texture.

[Chic Aeon]

Yep, I would have used Rolig's version also putting other parts of the lamp (or whatever) in the same map to use as much of the texture plane as possible and save download.

 

IF you were using a small overall texture and especially if you were using cycles render so you could easily adjust said fine grain texture, then you could likely use another method. Be careful (that means test) exactly where you line up the edges. Sometimes if you put them ALL the way to the edge you will get a dark line when viewed from any kind of distance.

 

And if you are actually going to use the dots as you show (honestly, I mostly looked at the screenshots LOL) I too vote for distortion over seam.  Frequently we have to make choices and frequently there is no perfect answer.

I DO hate seams though.

 

ANOTHER choice would be to do an overhead "project from view" with NO seam at all and then adjust the propotions to match your cone (that is bring the center circle in so there is more "length" than there would be on a projected overhead view. This would completely get rid of the seam and in SOME cases likely be the best choice. Again, it depends a LOT on the texture you are using.

Good luck.

[Drongle McMahon]

I don't think you can ever get the effect you are looking for from the planar honeycomb texture you are using. It will always give you either distortions or seams or both. I ams assuming you want nice regular rings of equally spaced cells. To map these onto a cone, what you need is circular rings with numbers of cells proportional to the radius. Then you can use the overhead projection UV map to get ir seamlessly applied. Here are two examples.



The top one uses rings of circles. That's easy to make, and the rings are correct, but the component circles are distorted into ellipses. So we can do better, at the bottom, by using rings of ellipses that compensate for that distortion. Here are the two textures.



And here is the uv map on top of the ellipse texture. The texture was simply made by using the spin tool on a mesh circle that was first stretched into an ellipse. Then an array mdifier was applied, and spin with n=5 x ring number. A screen capture from above (orthographic view) was modified in Gimp to get the final texture.