Le 05/10/2010 01:46, Simone a écrit :
> Jim Holsenback <jho### [at] povrayorg> wrote:
>> On 10/04/2010 04:07 PM, Simone wrote:
>>> I don't know about version 3.7, is it not possible to switch of the display
>>> anymore in that version?
>>
>> the -d option works like it always has ;-)
> 
> 
> Uhm, I'm a little confused now.
> In 3.6 I used to get an error with large images which said "failed to allocate
> display bitmap" but with -d it worked fine.
> 
> But if the -d option works the same in 3.7 I wonder why there was the problem
> with the large image fillibar wrote about in the first message?
> 
> Or does it mean that the display can be switched of with -d in 3.7 but still
> needs all the memory for the display (unlike version 3.6)? But I thought the
> main reason for switching off the display was to save memory (at least I can't
> imagine another reason to use it.)

In 3.7, there is the memory for the display, and the memory for working
with the blocks (unless the transfer to disk for that is compiled in,
activated and working) that each thread renders.

In 3.6, the memory for working is limited to 2 pixel-lines (previous one
kept for antialiasing, current one in progress), and it does not support
multi-thread rendering.

Had you read the other messages in the subject, you would know already
that there is an issue with the computation of the memory size for
working blocks. It has been found (and I personally tested the fix  with
a huge size, so I know that the identified reason is right), and a bug
report has been issued on the current beta. You will have to wait for
the next beta before trying again.

So yes, disabling display might still save some memory, but so far 3.7
is not as compact as 3.6 when used with huge size.

If you want be afraid, the current allocation (without special option is
5 floats (of 32 bits) per pixel, before the start of the render. Do the
maths for yourself, and keep in mind that when writing the final file,
you need yet another chunk because most libraries use a memory approach
too (but it is usually only 3 or 4 bytes per pixel), even if they
compress later the output before reaching the disk.

I got access to a 24 GBytes system, it is about just enough for 30500 x
30500 (to png). (it starts rendering at 18 GB...)

Might I ask on what display are you using a 41000 x 41000 picture ?
It took more than a 4m x 3m advertisement poster with the fine details
of handheld publication (10 pixels/mm).

-- 
Real software engineers work from 9 to 5, because that is<br/>
the way the job is described in the formal spec.  Working<br/>
late would feel like using an undocumented external procedure.

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