Weird bug on subdivision...

[starbase1]

I've done this many, many times - but this time it's gone wrong!

A highly subdivided tessalation sphere with displacement map and texture for the Moon.
But for some parts, chunks of it disappear! Like here at the top.

Now I was really using a lot of memory for this - I have 128 Gb, and it was about 65% used. The black triangles are big so they must be before subdiv.
And it happens again if I render that frame on it's own. Those polys are not flipped, (though it really looks like it). If I make those polys double side it will run out of memory...

Has anyone got any ideas?

(I'm still in the ancient history realm of 11.6)

Nick

 

[starbase1]

Ah, I think I have it.

It looks like LW can't handle quite that number of subdiv polygons, even if there's the memory available,
Dropping the level from 100 to 98 was all it took to fix.

 

[Sensei]

How much memory you have e.g. 128 GB alone is not the only factor.. what matters is how much of memory do you have in one large chunk possible to be allocated.

i.e. fragmented memory = application can allocate only as big chunk as the biggest continuous block of memory..

During session it changes as you work with the app.. After fresh start you should be able to allocate more than after a several hours of work.

Try LWSN freshly started.

 

[starbase1]

I've had a painful amount of experience working at the limits of memory!

If I exceed what windows can allocate, it thrashes around for an extended period then crashes...
And even when it works, it can take maybe 10 minutes to release the memory at the end of a render run. Much longer than it took to grab the memory in the first place...

Nick