How do I apply changes of one "island" to the rest of the islands of a mesh?

Particularly, if I want to tweak one leaf, which is part of tens others, so that I apply these tweaks to the rest of these individual islands automatically. Or at least, if I can choose the exact group of vertices on each and every leaf so I can apply my tweaks globally.

Needless to say, all the leaves are parts of one mesh.

They’re not part of one mesh, at least not in Blender terminology, and what wikipedia says about a mesh

They’re part of one object, which consists of multiple meshes. As multiple objects you have more headroom to change one and have others change. One way to do it is to use procedural duplication, face duplication for example, which also uses instancing.

And one way to get to that from what you have is to

  • select one mesh, duplicate it, separate the selection to its own object
  • select all the meshes and do a limited dissolve to make quad faces, which will give the duplicated objects their position and orientation
  • make the separated original object as the child of the edited object
  • and enable face duplication for the parent

In the example the child is next to the parent to show the relationship lines. The positions should match the faces in the parent when the child and parent objects (their object origins) are in the same place.

There are a few ways to work depending on what you want to do.

More than likely you will want to duplicate islands in object mode not edit mode so you can edit some kind of linked version of the mesh. Alt D for example to duplicate the object so that it is using the same mesh data block.

Then there are modifiers such as array used with a curve modifier to array something along a path.

Then there is dupliverts to instance something along geometry of another object,

If you want something with a lot of control and complexity look into animation nodes. They can also be used to create complex geometry you can latter apply.

Thanks for the thorough answer! First of all, I thought that a “mesh” can have loose parts, and these loose parts make up one entity which we call a mesh. Where an “object” is a different kind of entities and is represented by a box, sphere, cylinder…etc. I don’t know honestly, I’ll follow your logic.

The Face Duplication was an awesome idea, that’s genius man. I had to struggle with the origin points a little bit, but it finally paid off. I welcome any other shortcuts though, but until I find one, I’m gonna go with the face duplication trick.

Thank you! will go over each and every method, although I don’t think I’ll try the AN as i still haven’t wrapped my head around it yet.

Just want to jump in and clarify from my understanding, and how I look at it. Blender is made up of Data Blocks. In regards to mesh objects there are two data blocks. One is the Object data block and the other is the Mesh data block. And Object data block is linked to a Mesh data block. So when you are saying “part of the same mesh”, it terms of Blender concepts you are usually referring to the Mesh data block. And I am pretty sure that is what you meant. From there you can say there are contiguous meshes and non-contiguous meshes. Meaning basically islands.

Recently we had a project at the studio and we looked at various ways to model something. I thought of Animation Nodes as a solution and so I had an artist learn them. I think once you do get your head around them, you will use them a lot.

There’s no confusion about how the model is constructed in this one because of the correctly provided full interface screenshot in the OP. It’s just the term that bugs me.

The problem with the term “mesh” is that people use it to describe a model with one object, multiple objects, connected and unconnected geometry. No one asking questions refers to a mesh as the object data datablock, not knowingly at least.

With modeling questions it’s important to know if the user is talking about one or multiple objects, and if the object in question has one connected, or multiple unconnected mesh parts. Object and mesh are both singular, and talking about either datablock doesn’t take into account how the mesh elements are linked. Object and object data datablocks are the same in that regard, they both contain the same data, one is just higher up the hierarchy.

Talking about objects, which are manipulated in object mode, it’s clear what the user refers to. Also talking about meshes, as multiple mesh parts, it’s clearer that there are multiple unconnected parts which one edited object consists of.

That’s the long way of saying: objects in object mode, meshes in edit mode. Plural when there are multiple, and it’s much clearer, at least to me.

For copying UV’s of leaves is this sort of instance, I use Magic UV, which has a UV copy/paste function which works very well.