Colliding Mesh Geometry and Import into Game Engine

[ophtha]

This is a question regarding best practices for 3D modeling and import into a Game Engine (Unity).

This is probably best demonstrated with pictures (please see simple example demonstrated below in Blender):

I want to have one model in game, which has several “sub-models” attached to the same mesh (this could be eye into character mesh, or wires into robot etc). Often, other artists will leave these “sub-models” as intersecting the base models geometry (like teeth into gums, as opposed to the teeth geometry extending directly from the gum geometry) - is this alright?

In Blender I could have these as separate objects in the same project or separate meshes within the same object - is it okay for them to intersect and for me to import them this way into Unity?

Internal faces within a mesh in Blender can cause rendering issues, so in the example below I deleted the face that would be intersecting. Understandably these backfaces would appear transparent in Unity as they are not rendered.

Thank you,

[yogyog]

I really don’t think this will cause any problem. These overlapping meshes count as being part of the same object for the purpose of collision. Deleting a face that will always be hidden is a good idea, and will speed you up a fraction, but it will work without you doing this.

There is an option to cull backfaces in the view options in Blender (right-hand panel of the viewport) if you want to see the same thing that you see in unity.