Combine same materials into one during mesh import

I use many 3rd party meshes, some of which are skeletal meshes of characters. It is pretty delicate to alter those meshes in 3DS. Many of them consist of different body parts that are separate objects but are all on the same skeleton for instance a character, head, a sword. All separate objects but rigged to the same skeleton.
When I import these, UE combines them into one object, which is good, but has a separate material for each ex-object even if all objects use the same material. In 3DS the only way I can alter this is by attaching the meshes to each other, re-rigging them and then combine the multimaterial elements which use the same texture into one material element. That’s a lot of work.

It would be better if there was an option to “combine same materials into one draw cal/material” when I import a mesh into UE.

Hey Wallenstein,

We have actually added and improved the feature for combining multiple actors and their materials for optimization purposes. This tool is called ‘Merge Actors’ and can be found by navigating to Window > Developer Tools > Merge Actors. This was taken out of experimental within the 4.12 engine release.

4.12 Release Notes

To clarify your request, you are wanting this tool upon import to combine actors and any duplicate materials into a single material to reduce draw calls? Do you have objections to doing this after import? I can see potential issues with other users having this option available during import, and want to find a viable solution for all users.

Thanks, I dont have 4.12 installed yet. This looks like it is in the actual scene editor and best used for static meshes. I include two pics here to illustrate my situation. The first pic shows a character in 3DS. Like I said, it’s a character I bought from a website, so it’s not my doing:


As you can see, it consists of multiple objects, most of them use the same texture, yet they are in separate objects. making changes here is very difficult since you cant simply attach one object to the other even though each object has a skin modifier. The resulting object will not deform correct anymore.

When you import this object you get the following:

Here you see one material element for each original object in 3DS. The objects are all correctly combined into one, yet for each original object there is a material element, which may me what the user wants in some cases, but in some cases you would prefer to have identical materials combined into one element.
So I think there should be an option when you import such a mesh that gives you the option to combine material elements with the same material/texture into one element. Idealwise it would give you a list of the original object names from 3DS and allow you to combine certain elements into one while leaving others as separate elements.

That’s my issue too…

Hmmm, I think you could resolve this issue if you setup correct material ids in max, this way even if they are attached or are separate objects the imported objects will always come in with the right amount of elements. As long as they share the same material those objects should come in correctly seen as one element ID in UE.

I haven’t had this issue with my imports.