Question about unjoined/unconnected mesh/object

Question

The highlighted cube is not connected to the mesh below, is it going to cause issue ? I've seen couple people did this and from what I've learnt, everything must be connected?

Answer 1

I think there are two questions here:

1. Should the parts of my model be manifold?

2. Is it OK for my model to comprise several parts, manifold or not?

For all the reasons given in it, the first question has a nice answer here

As for the second, IMO, wherever possible, model parts which are separate parts in the real world as separate parts in the model. Reasons not to do that include:

• 3D printing as one piece.
• Needing a surface to behave well under (possibly unrealistic) deformation when animated
• Economy. Simply reducing complexity and poly-count, modeling time.

But you often see people struggling to achieve good topology across regions of a model which could be separate surfaces with no harm done at all.

Answer 2

In short, Mesh data is just container of vertices, edges, loops and polygins with uvs, color, materials and a whole lot more.

Theoretically all Mesh objects in your scene can be packed in single Mesh data, if they properly created, especially normals.

is it going to cause issue ?

This should not cause a problems!