Master copies of objects

Support Modeling
1

So here’s my problem :

I want to build a series of sci-fi ships in different blend files. But I want them to have common parts - say, a gun turret with a gun on it. So one ship might have two of these turrets, another four, another six. But then if I want to modify the turret design it rapidly becomes a pain, because I edit one and then have to go around changing all the others, or re-appending the improved version into each file.

What I want is to be able to have a “master copy” of my gun turret, with the ones used in each file as copies of it. So then if I improve the turret to add more detail or whatever, I can just edit the master copy and the rest change automatically.

Now I figured the best way to do this was to make the turrets on my ships linked objects from the original master. That looked great to begin with - but I couldn’t then move the turrets on my ships, or even put them in place, because their location and rotation was linked to the original file.

I read that a solution might be to make the turrets on the ship a linked object, and then convert them to a proxy. That seemed to work perfectly, just what I want - I could move my turret around to place it on the ship, and rotate it as needed, yet if I edited the master copy to add more detailing the proxy copy updates too. Perfect.

Only then I try to repeat this process with a second turret on my ship and it gets very confusing. I try to bring in both turret and barrel, but only the turret appears. And then it’s like the two proxies are linked together, so moving one moves the other.

I read what I could find about it, but the only solution I’ve found was to make multiple copies of the original file and then make each turret link to a different one. But that defeats the whole object of the exercise, which was to have one master copy of the turret I could fiddle with the design of.

What I need, I think, is to be able to have multiple proxies of the original object, each able to be positioned and rotate independently of one another - while still having their shape/material coming from a mater copy that I can edit.

Is there any way I can do this?

Any suggestions or tips appreciated.

2

Hi,

Let me make sure I understand your problem. When you say you are making proxies, are you talking about linked duplicates (by selecting the original and using alt-D?) or some other method? Also, I’m unclear if you are linking the same turret file twice or two different turrets. If you are just using one turret multiple times, only link it once and just make two linked duplicates by selecting and pressing alt-d twice. You’ll be free to move them around and they will follow the original mesh as it changes.

3

Simple answer… You need to Link rather than Append your objects to other files. Then you work on the master and all changes are automatically made to the linked ones. Beyond that, I know nothing.

4

I did try this. I hit ctrl-alt-o and add the object from the master file. It sits in the scene, outlined in blue. But when I try to move it or rotate it, nothing happens - it just remains in place.

5

I did some googling and found a thread where somebody said a solution would be convert the linked object in a proxy object with ctrl-alt-p and then you could move/rotate it.

Now that seems to work. But the problems come when I try to then bring in a second copy of the master turret into the same scene. I tried using ctrl-alt-o to make another linked copy, and then ctrl-alt-p to make it a second proxy, but it just doesn’t seem to work. I either get another linked copy that won’t turn into a proxy (generates an error message when I try) or making the second seems to interfere with the first.

Also, I’m unclear if you are linking the same turret file twice or two different turrets. If you are just using one turret multiple times, only link it once and just make two linked duplicates by selecting and pressing alt-d twice. You’ll be free to move them around and they will follow the original mesh as it changes.

What I want is a scene with multiple copies of the master object in it, but with each copy able to move/rotate independently. In other words, my ship will have several turrets on it at different locations, each of which can rotate independently of one another. But if I tweak the design of the master turret, it will show those changes on all turrets wherever they are used.

I tried simply making a copy of the first proxy object I made (by using ctrl-alt-o followed by ctrl-alt-p), but it acts very weirdly - bits of one turret seem parented to the other, moving one makes the other move, etc.

I could do with finding some tutorials or something on the subject, but I can’t find much about it online.

6

It seems like my original advice applies. Rather than make proxies, link one copy of the file into your blend and tuck it away in some layer. From this object make a linked duplicate by selecting and pressing alt-d. You can move this duplicate anywhere as you like. It shares the same mesh as your linked file so if you update it, the linked duplicate will update as well. You can make as many linked duplicates as you like with alt-d, and they will all be independent objects but share the same mesh.

7

Aha, that seems to be doing it! Thanks a lot for that!