How to separate one GameObject into multiple pieces

Sorry for another rookie question, but is it possible to break up a game object into other pieces? If so, how would I go about doing that? I assume this is much easier than I think it is, but I'm just playing it safe as to keep from breaking anything Thanks so much for any help.

 

You shold use blender for this purpose or other similar application. In unity it is impossible

 

Breaking gameobjects into pieces can be done by creating other gameobjects and putting some of the scripts from the first one onto these (if they don't have relative references to certain hierarchy elements). But you're most likely wanting to know how to split geometry/meshes; and that indeed should be done in a 3D-modelling package. It can be done inside unity, but is not recommended and can potentially be very complex, depending on the model.

 

Or, depending on what you're trying to do, you may find something in the asset store that does it. There is an asset called (IIRC) "Exploder" which does a pretty good job of exploding most meshes. Or, for Beatron 2000, I wrote a little script that breaks any mesh into its constituent triangles, and sends those flying (for a Tron-like explosion).

 

Just commenting because the advice here is lacking and pushes using 3rd-party 3D software to make "pre-broken" versions of models. It is possible to break apart things in Unity during runtime, without having to break apart objects in a 3D editor or ProBuilder and then switching objects during runtime. It is quite easy breaking a mesh apart into shards, chunks or any shape you want really. Two things to consider are models broken into vertice triangles will slow down Unity if there's too many of them. Also, meshes are hollow, so when you break them, you have to also weld the pieces so they look like solid chunks. It isn't hard to have the texture applied to the pieces so that the pieces keep their texture. I have written a script that creates a Voronoi fracture to any mesh object in Unity, and it also starts the Voronoi pattern generation from the initial collision point to give a realistic shatter to the mesh object. I will post a more basic version of the script here soon when I get some free time, but in the mean-time, read up on Unity's mesh filter component.

Just as proof that it IS possible to break up a game object into other pieces and it will look realistic and work fast, here is a screen shot of a test-game running in Unity that uses different versions of object shattering in real-time, breaking the actual mesh into chunks:

(The objects are the white ones which weren't textured yet, the grey square is just to hide the test-character.)
The headless Statue of Liberty can be seen in here, broken in realtime and automatically welding the base model and the chunks to fill in the holes in the meshes. This was a test using Unity 5. I have more projects and some using Unity 2018 and 2019 and I will post more here soon. Not the best screenshot, but it is proof that even complex models can be easily broken in Unity, without Blender or premaking broken versions of the original object and swapping them, it also worked near-instantly fast, even on an old Windows 7 32-bit system.

Here's a couple of demonstrations from others using Unity, shattering objects in realtime:

http://emretanirgan.com/portfolio/dynamic-voronoi-fracturing/

and....

https://keithmaggio.wordpress.com/2019/05/28/links-voronoi-symphony-of-destruction-and-more/




All the pics posted are from Unity projects, and works on versions 5 through 2019 (maybe earlier too).

 

Looking forward to some code for this, way beyond my head to work out,but I'd love to use something similar.

 

How exactly do you do this bit?
3. Use ProBuilder to select the faces you want to "break off" to a new mesh

After probuilderizing I dont see any menu or anything come up.

 

There should be a feature builtin to allow the chunking of meshes, say you have a huge mesh and want to divide it into 4 separate parts for more efficient rendering.

 

Needs to be done runtime for generated levels

 

Sorry I haven't had a lot of time and I have been flooded with projects to work on, but those links I posted should take you to those free example projects. Most, if not all have tutorials to follow.

 

Just ran into this issue myself. It would be really convenient if the Probuilder API had the ability to detach faces as gameobjects/submeshes. You have to option to do so in the editor, but I can't find anything related in the API documentation beyond proMesh.DetachFaces(). There doesn't seem to be a straight forward way to convert the detached faces to gameobjects.

 

I have spent a lot of time experimenting with mesh manipulation in Unity, and I had success with using scripts to do all sorts of things with faces and submeshes. It can get a little harder dealing with sub-meshes, but maybe try searching online for Unity code that deals with mesh/face manipulation.

 

Really interesting article:

https://www.raywenderlich.com/3169311-runtime-mesh-manipulation-with-unity

 

You sir saved my LIFE! I am new to Unity and I merged all of the walls and floors of a room WITHOUT giving them a material first. Just now I realized my mistake but you saved me!