Beginner questions, joining objects in blender and exporting to unreal

Hi everyone, what’s up, I’m new here :slight_smile:, I like to do pixelart and digitalart, and now I’m into 3D art too, I’ve been learning 3D on both blender and unreal engine, I have many questions about it that I will be asking here

First I wanted to ask about something I keep getting stuck with
If I keep my model as many objects and the textures as multiple images, when exporting it into unreal engine, it comes as multiple pieces, I discovered I can drag it together and it comes together, but later it’s hard to make order of it, having to select everything to move it, and the content layer folders becomes confusing, also the textures aren’t imported properly most of the time, sometimes they are and sometimes not, only fix I found was to manually set the materials on unreal, and it’s really impractical so I think I’m doing something wrong



Another example, I also tried to join all the model objects together, but a lot of times the uv maps and textures gets messed up. So I learn how to bake textures, so I bake them and join the model as a single one, it was easier to export the models and textures to unreal, but harder to make all the baking process. but if I wanted to edit it, I had to use the non baked model, edit it, and having to rebake it and rejoin it again. The models I downloaded from 3d sites seems to be a single object with baked textures like this, so I’m not sure if this is the correct way to do it, or if I should avoid this steps and just keep everything as multiple objects or joining without baking, or maybe there’s another method I’m missing.
Also, my main concern in 3D is performance, since I have a low-mid end pc, so I can’t afford high graphics or too much memory use, so I wonder if the single objects and baked textures helps with it, or if it’s okay to use the models as multiple parts and textures? I can’t decide, I can see both good and bad points for both methods


4

I couldn’t find an answer about all this anywhere, someone that knows about it can please advice me? :slight_smile:

If you join the objects then each part usually does have it’s own UVmap and also their own material. Here i joint the default cube with some UVgrid map and Suzanne with the UV colormap into one object and both parts do have their own material:

There are also lots of info about exporting to several game engines… often by the game engineers themself… :wink:

1 Like

Interesting, I did that on some of my tests, but sometimes the textures or meshes got messed up, if they look right like yours when I open the uv maps they’re all mixed together, is there a way to see the uv maps separated from each other?

You mean mixed up UV’s like so (again cube and suzanne):

…that’s normal… the object just have one UV map for all faces but they are “linked” to different materials…

You may have to elaborate this to get a more suited answer.

1 Like

As @Okidoki said, when multiple objects with UVs get joined the UVs get joined also…that is normal. The next steps are what you would normally do to export to a game engine.

With the UVs mixed like this, select all in the UV space then select
UV > Average Islands Scale, and you get something like this…

With everything still selected select UV > Pack Islands…

and then you get…

Now you have a good UV that you can use to BAKE down the textures to a single image…
as shown here…

this allows you to export a joined object with just one material to your game engine…

Happy Blending!

2 Likes

Yes, my UVs always look like that when joining objects, and sometimes the textures looks messed up too or overlapping each other, other times they look right like they were before joining them

Yeah, those methods looks good, I will practice them. For this model I made, the baking I practiced it with a video from the same youtuber, but it was older, I will see this updated one, he has good videos, and for unwrapping the maps I remade them marking seams and using smart uv project, Now I will practice the pack islands tool

1 Like

Again: this is normal for different faces using different materials; you select the UV accordign to the material. Expect if you really want only one map then may have to to arrange, for example using any quarter of the map and merge the textures or use the mentioned re-bake when re-mapping the map.

1 Like

Thank you both for the advice :+1:t2: :slight_smile:, I practiced more, I’m getting more experience with this. I joined the model, and arranged the maps with the pack islands, and did the baking like the video, and then exported it. I’m getting more used to this methods, I will practice them more with my other 3D models



1 Like