What are the limitations for modifying a 'source' object with multiple instances?

CA415

In SOME cases I can successfully add additional objects to the source object with multiple instances, and all instances reflect the change.  But, in other cases the instances will NOT reflect the change.

What are the limitations or rules for modifying a source object with multiple instances?

felis

To my lmowledge.

If it is an instance (created as an instance) it is identical to the original except transforms (incl scale).

If it "just" is a duplicate, it will share geometry.

CA415

Thanks for the feedback.

I do understand the difference between an instance and a duplicate of an object.

I've identified an inconsistency in modifying a source object where a modification doesn't always appear in the instances.  Sometimes the change appears in all instances, sometimes it doesn't.

That's why I was hoping someone could help by providing the rules and limitations relating to instances.

algovincian

felis said:

To my lmowledge.

If it is an instance (created as an instance) it is identical to the original except transforms (incl scale).

If it "just" is a duplicate, it will share geometry.

It's the opposite. If you create a duplicate, as opposed to an instance, the duplicate can still share memory on the video card for textures if the maps are left alone and the same ones used (but they don't have to be, unlike instances). Geometry is not shared which is what allows for adjustments other than transforms (shapes, poses, etc.).

I've always thought this was an interesting choice for a naming convention because in programming, instantiating a class, or creating an instance of a class, is necessary to actually set values for variables (each instance can have different values).

- Greg

(edited for typos)