When to break up a model into pieces?


I’m mainly a programmer who dabbles in Blender but I’ve been inspired by some of the recent Oculus Rift VR projects I’ve seen and want to try my hand at modelling a high detail ship environment and I am wondering how best to break this up and export to UE4, or if I even need to break it up.

I’m using substances and baking out the normals/ao and applying to a decimated version etc. but the questions I have are things like:

  1. should I use separate meshes for all the different pieces or just try to export one big mesh except for the interactive components(this would be a lifesize ship, say equivalent to a spanish galleon)
  2. Any gotchas as to modeling the inside of the ship? I have seen advice that I should create an entirely separate model for the inside and just place it inside the outer shell?
  3. If I break the ship up into pieces will it cause physics issues?

Any advice from seasoned modelers appreciated, thanks!

Each mesh gets a single lightmap, so at the very least you have to consider how to break it up so that you get enough coverage with your lightmaps, otherwise the highest resolution lightmap won’t give enough shadow detail.
You also want to break it up so that it can hide pieces that aren’t visible. It’s a balance though between getting the least amount of things in memory, and the least number of things because each separate object is a draw call so increasing the number of objects can slow things down.
Physics aren’t a problem, you can model a physics mesh separately.

Ah ok I didn’t even think about the lighting aspect, makes sense. I prefer to break it up into a decent amount of parts just wanted to make sure. I’m not too worried about drawcalls but I guess I’ll just have to see on that one.

Check out the Realistic Rendering example. All the walls, floor, ceiling, stairs are separate static meshes. The actual level is then composed in UE. This might be a little bit more tedious when creating all the assets, but it gives you more flexibility in designing your level.

Also, usually you’ll create your materials, lighting, (particle) effects inside UE. If your entire level was on big mesh, you’d have to define dozens or hundreds of elements, to be able to assign different materials to walls, ceilings, objects, etc. It’s probably easier to just split them into separate assets.

Hi Tiggus,

DarthViper107 and Bajee are correct with their posts. There are quite a few things to consider when building out levels. Modularity is a great way to build a level using minimal number of assets. You would build your main pieces you would need in your 3d modeling program then reuse and assemble those into your level.

There are a lot of good tutorials out there for building levels using modularity:

Thiago klafke’s Tutorial: Link Here
3Dmotive Modular Building Tutorial: Link Here
Hourences “Solace Project”: Link Here

These are a few of my favorites and I hope they help get you started.

Once you’re up and running, feel free to post what you’re working on in the WIP section and get some community feedback!



Many thanks for the advice and links, will check it out. I’ve got the DK2 on preorder so the clock is ticking :slight_smile: