Re: [Flightgear-devel] Repeatable random seeds

2011-09-16 Thread Andreas Gaeb
Am 15.09.2011 22:24, schrieb Stuart Buchanan: [...] This is a bit trickier to fix in concept, because we want there to be variation in the clouds between runs rather than generating exactly the same set of clouds if you start in the same location with the same weather. yes, this is very

Re: [Flightgear-devel] Repeatable random seeds

2011-09-16 Thread Csaba Halász
On Fri, Sep 16, 2011 at 10:35 AM, Andreas Gaeb a.g...@web.de wrote: However, the sg_srandom_time_10() function also looks appealing. That would give the same random seed for all processes started within the same 10 minute interval, yet also vary every 10 minutes even with the same METAR.

Re: [Flightgear-devel] Repeatable random seeds

2011-09-16 Thread Erik Hofman
On Fri, 2011-09-16 at 13:22 +0200, Csaba Halász wrote: On Fri, Sep 16, 2011 at 10:35 AM, Andreas Gaeb a.g...@web.de wrote: However, the sg_srandom_time_10() function also looks appealing. That would give the same random seed for all processes started within the same 10 minute interval,

[Flightgear-devel] Repeatable random seeds

2011-09-14 Thread Andreas Gaeb
Hello everybody, lately I've been working on a multiscreen setup driven by multiple host machines. In order to get the same random scenery objects, all machines need to use the same random seed. Up to now, the random seed is taken from system time, which leads to inconsistencies. The

Re: [Flightgear-devel] Repeatable random seeds

2011-09-14 Thread Erik Hofman
On Wed, 2011-09-14 at 11:18 +0200, Andreas Gaeb wrote: Hello everybody, lately I've been working on a multiscreen setup driven by multiple host machines. In order to get the same random scenery objects, all machines need to use the same random seed. Up to now, the random seed is taken

Re: [Flightgear-devel] Repeatable random seeds

2011-09-14 Thread Stuart Buchanan
On Wed, Sep 14, 2011 at 10:43 AM, Erik Hofman wrote: Is this broken.. again? Sigh. I've been pushing this behavior various times and scenery objects should always be positioned at the same location over and over again. This may just be broken in the default 3D clouds code. I'll take a look.

Re: [Flightgear-devel] Repeatable random seeds

2011-09-14 Thread thorsten . i . renk
Thorsten Renk - If this something we need to be thinking about for the Local Weather as well? We've been tossing the idea around in the forum that Local Weather stops using the rand() function from Nasal and uses its own internal random number generator. In this way, it could be initialized in

Re: [Flightgear-devel] Repeatable random seeds

2011-09-14 Thread Stuart Buchanan
On Wed, Sep 14, 2011 at 11:18 AM, Thorsten Renk wrote: Thorsten Renk - If this something we need to be thinking about for the Local Weather as well? We've been tossing the idea around in the forum that Local Weather stops using the rand() function from Nasal and uses its own internal random

Re: [Flightgear-devel] Repeatable random seeds

2011-09-14 Thread Erik Hofman
On Wed, 2011-09-14 at 13:33 +0200, Andreas Gaeb wrote: Am 14.09.2011 11:43, schrieb Erik Hofman: I've been pushing this behavior various times and scenery objects should always be positioned at the same location over and over again. To clarify things up a bit, not all is broken: - Houses

Re: [Flightgear-devel] Repeatable random seeds

2011-09-14 Thread James Turner
On 14 Sep 2011, at 12:00, Stuart Buchanan wrote: OK. We've got something similar already in the C code for exactly this purpose. Might be more efficient to simply expose that over Nasal, but I'm not sure how easy that would actually be. Pretty trivial, for a function such as sg_random,