Some (very) basic questions regarding file optimization for texturing meshes for use in game engines

Turbopasta

I know how to do many things in Maya, but I'm still foggy on the best ways to implement things I make in 3D into things like modern game engines (Unity, Unreal) since I haven't spent as much time in them as I've wanted to so far. I think I generally just have some confusion when it comes to implementation and workflow.

In Maya, let's say I'm working on a semi-complex building with many different pieces to it. Door, roof, doorknob, mailbox, all with different colors, and possibly different alpha and specular channels. Would it be more optimal to go into Maya and individually assign different arnold textures to each of these things, or should I take all of these things and assign them one giant texture? I know file size can be a concern, but what is there to think about besides that? Are there any issues with compatibility if I choose to take these things into game engines like this? How about if I do this with AI textures? How do these things compile exactly? Is one choice clearly superior to the other? Or is there something even smarter to do here that I don't know about? Can game engines like these handle AI textures properly or do I need to stick to using lamberts?

I don't expect for all my questions to be answered, or even for them to make sense, I'm just a little hazy on how best to proceed from this point on. Thanks for reading.

musashidan

Engines like UE4/Unity are using real-time PBR shaders. Offline renderers like Arnold are using their own proprietary shaders. They are completely different shading models and are not compatible. Offline renderers are starting to adopt the map channels of real-time engines to recreate the material, but not the shader itself. Each and every single renderer(real-time and offline) has its own unique shading model. There are systems like OSL(open shading language) that attempt unification, but again, it is at a map level rather than a shading level.

If creating a complex building/level for use in UE4/Unity it would be done using a mix of modular and unique meshes, and tiling and unique textures. This is a very general and simplified answer I have given, but it is a very in-depth subject. As you are completely new to creating assets for use in a real-time game engine environment I would advise spending as much time as you need on the Polycount WIKI. There is a huge amount of info to digest so it's a bit out of the scope of a forum post.

http://wiki.polycount.com/wiki/Polycount

Eric Chadwick

In particular here and here
http://wiki.polycount.com/wiki/Modular_environments

http://wiki.polycount.com/wiki/MultiTexture

Best of luck! It's a fun topic to work on!