I had a thread in another forum of blender artists but was advised to bring it here to see if anyone in the technical part of the forum can help with diagnosis. Everything I know, suspect or have been suggested so far is listed in the link below.
One thing that isnt mentioned in the other forum is linked duplicates & dupligroups & modifiers
Should just mention instancing and linked duplicates mean the same thing
So, If ever you duplicate something in blender which is essentially the same but just in a different location / rotation / scale. always. ALWAYS use alt d instead of shift d. This means that the vertices behind the object are linked, so it stores it once in memory when rendering. If there is a modifier on a object that you aren instancing around, and the modifier is also the same over all the objects, apply the modifier. Why? because no matter what, if there is a modifier on the objects, it removes the instancing benefits.
When you copy / paste between scenes, make sure that you are copying all the linked objects together, otherwise each copy paste will remove the instancing and create unique objects when bringing it in.
Finally. the big one. Even though they are linked. In the blender viewport, it will load everything which can be edited directly, up into ram. Which means if you have 5x2million poly objects. whilst at rendertime it is only loading up 2million into ram, the full 10million will be stored into system ram for the viewport. I suspect this is the reason for your crashes.
Now. There are a couple of ways around this. Converting the object to dupligroups will make it not editable, but you will be able to see it in the viewport, save on system ram, and gpu ram. This is how we are able to load the scene up with billions of polygons and still be able to work in the scene.
If there are loads of these high poly objects scattered around in a random configuration, particle system -> hair -> object duplication is the most efficient way.
It should be noted, that whilst your scene may be able to open the viewport speed may suffer immensly… the only way around this is to change the object display to wireframe / bounding box. ifyou donit need to see it and its high poly, i highly recommend this.
If there are any sample scenes i can take a look at tell you where exactly to optimize.
I don’t think this is a ram problem like that, if I copy pieces of geometry in one by one (which is no good to me as it breaks the rig) then the computer is able to cope fine with having all the geometry in the viewport, and it can render too. If it were a ram issue of that kind I woudn’t be able to copy the geometry like that, or render, without a crash.
If blender crashes for no reason, then its a bug. If you can reproduce this bug reliably then it should be reported.
If it crashes for lack of ram, or it just lags. then its your computer and is not a bug.
Do you have the file available for testing purposes? can you simplify the scenes to isolate out the crashing?
Seems to have been already reported as a bug, and resolved - https://developer.blender.org/T52099
So my file is fine then? I just need to wait for the next version of blender? I needn’t worry about making other files which build on this file as there is no corruption in it, just a bug within the blender program which my file unfortunately sets off? Is that the correct assessment of the situation? I’m just a bit worried about the risk that my file might be corrupt as it’s something I want to append and then build upon in a much biggher project.
It seemed to work with a nightly build? The questions from my post #7 still stand. Yours appreciatively