Limit to number of assets per tile...?

[Wikkus]

Hi peeps.

I'm sure this must have been asked before, but I'm damned if I can find it -- maybe I'm asking it wrong or can't drive the search-engine

Anyway, it's pretty much as per the subject line and it's frustrating as hell: is there a limit, be it a "hard" cap, i.e. enforced by the editor which says, "sorry, too many assets on this tile", or, "soft" i.e. a notional limit after which performance is massively degraded or the program starts to crash to desktop, predictably?

Logic tells me that the answer to the latter is dependant on the resources available to the program via the Operating System, in other words, how potent your PC is, but I'm keen to understand what the actual case is.

What's posed this question at all? Well, I've not yet dived in to the route building myself, however, I have been massively frustrated in my scenario writing due to a spate of crashes, to which there appears to be something of a pattern emerging. I've not nailed it or anywhere near proven this to be the case and before I go off barking up the wrong tree, I'd ideally like some feedback from you guys and maybe even any passing devs, but, my theory (for what it's worth) is that it's something to do with the (in)ability of the disk I/O to feed the game engine with data when transitioning from one zone to another or conversely, for the game engine to render those assets in a timely manner which causes an abend.

The CTD I see most frequently is where I am transitioning from a tile with circa 1500 assets on it to one with over 2000 and then straight on to one with over 2600 on it. Combine this with around 15 AI services plus the player service all doing their thing and it is, on average, about 50/50 whether I'll hear that lovely "doomph!" chord that signals a procerror and find myself back at the desktop...

So we're clear, my scenario starts on a tile with 2410 assets on it and I then travel through tiles with the following numbers of assets:
1202
1208
1018
1034
1273
1363
1340
1272
1289
1343
1301
1321
1554
1781
1848
1749
1959 (stutter here, usually)
1827
1938
1873
1818
1930
1928
1557
2088 (occasionally CTD here...)
2662 (...but more often CTD here )
2058
1778

This usually takes 18-20 minutes (depending on how carefully I modulate my speed) and that massively busy tile is where it usually goes bang.

Thoughts? Views? Help?

Thanks, Rik.

[OrpheusRocker]

I'm up for some testing. How do I get the asset readout? Logmate?

[Wikkus]

I'm up for some testing. How do I get the asset readout? Logmate?

Hiya, I'm only going by what the readout wossname says in the bottom-left of the Editor screen...

Rik.

[OrpheusRocker]

Are you saying that you get CTDs when you're in the world editor?

Andy

[Wikkus]

Are you saying that you get CTDs when you're in the world editor?

No, I generally know when to expect a CTD in editor and try and avoid some of the things that seem to provoke that...

This post is more to do with when doing a run-through in game. I'm aware that it's (usually) asking for trouble to try and play a scenario after an editing session, so I'll generally quit the game first, then go straight back in and run the scenario.

More often than not, it'll get to that same point and CTD

Rgds, Rik.

[GavNormandale]

which route is this?

could it be a case of your RAM overloaded?

cheers

Gav

[Acorncomputer]

Hi

This was something I was concerned with in Rail Simulator -

http://forums.uktrainsim.com/viewtopic. ... 18&t=82464

I think the assets in RailWorks are more frame rate friendly but the experience may be of use.

[Wikkus]

which route is this?

{sucks air through teeth}

Being deliberately vague, what if I asked if we could leave that as "not important" for now, Gav?

I only say because I'm most interested in the answer to the question itself because it may have a bearing on what I do next on my own planned route or

indeed with my machine...

could it be a case of your RAM overloaded?

You may well be on to something here, Gav... Ordinarily, I'd be likely to fall immediately into the "probably not" camp -- I have 4GB of fast DDR2 RAM and I'm

running a 64-bit OS -- HOWEVER, I just checked the amount of free (physical) RAM when I load the scenario in question, and at the beginning, there's

only about 400KB... That was quite a surprise.

Okay, so then I dumped my browser session and the RW launcher (once launched...) and checked again. I've clawed back about 420KB, meaning I'm now

starting with 820KB-ish.

If I then check it as I go along, I see it decrease all the way to the (usual) fail point, dipping to 675KB at the point where it fails most often.

That is only 145KB difference, however, if the same ratio is applied with a 400KB starting point, then we're well into disk-thrashing territory...

I continued on with my test and got all the way past the usual fail point and had just crossed the boundary into the tile with a "mere" 1778 assets on

it, so in theory, RW should be releasing RAM, right? At this point, I check available physical RAM and we're down to 654KB. Almost immediately

after, it CTDs :s

I need to set up an Event Log trace for this, I think. It's late now and I'm tired. I'll resume testing, tomorrow.

Cheers, Rik.

[GavNormandale]

i just mention the ram as you say you have moved from a tile with in excess of 2000 items to another with excess of 2000 items, what if 1 tile has most of the said objects close to the border with the next tile and the next tile has most of the objects adjacent to the previous tile, then most of the content will still be rendered, so could be 3000-4000 objects in the RAM, just because you have crossed a tile doesn't meant the rest is forgotten

be aware i am not computer savvy, this is just my sort of logic

at the end of the day, as a past user of trainz, 2662 items of content in that sort of area isn't bad, i think if i loaded a trainz route with that sort of detail my PC would probably refuse to work ever again, as with anything there has to be a cut off point so i guess below 2000 items per tile is safe with a decent PC, what is the official guide to items per tile in RW?

[Bullet399]

i have similar experience here. When asset are about 1800 - 2000 i get stutterings and sometimes CTD if tiles in neighborhood with more than 2000. My first try to find a solution was to swap 3D Trees with 2D Trees and so on as i had the suspicion that some assets need heavely ram. Result was the same, stutterings and sometimes CTD. Only reducing Assets below 1800 was curing this behavior.

I think that uptodate Computers have a little bit higher tolerance about this.

[bigvern]

A couple of tiles on my Heartbeat Moor route had > 2000 items but some of those were repeated many times, i.e. trees used to represent thickly wooded areas as there are no single forest objects as found in MSTS. However I did try and keep an upper limit of 2000 per tile, despite nothing official ever put out by Kuju/RSDL/RS.com about any hard coded limit.

[dlljones]

I'm glad we are having this discussion as I'd assumed it was something to do with the power (or lack of power) of my own PC. I've started to save a journey using th F2 button at regular intervals now so I can resume at some point without losing all of the journey. This was something I had to do when I used MSTS and was one of the reasons I dumped it in favour of RS/RW. I'm not an expert at all so I can't offer any help other than to say this error usually happens when I'm going from a sparsely scenic point in my route and approaching a highly scenic point. I can see the assets building up in the distance and I know it's time to press F2. If I'm driving through a lengthy bit of highly scenic stuff then mostly I don't get this problem. The route I'm usually driving on is my own creation and there are many scenery gaps as I tend to concentrate first on stations and working out from there.

Don't know if this posting helps matters or merely adds to the problem but I hope a solution can be found to this recurring and very frustrating problem.

Llew

[Wikkus]

Many thanks Gav, Michael, Vern and Llew as it all helps aid the understanding. There's some shared experience showing with the limitations and it suggests that around 2k items is the "comfortable" limit after which problems start to set in.

To add detail, it'd be useful to know how much system RAM you each have and what operating system you're running on to see if there's any commonality there, too.

Incidentally, Gav, that's a sound piece of logic where you say

i just mention the ram as you say you have moved from a tile with in excess of 2000 items to another with excess of 2000 items, what if 1 tile has most of the said objects close to the border with the next tile and the next tile has most of the objects adjacent to the previous tile, then most of the content will still be rendered, so could be 3000-4000 objects in the RAM, just because you have crossed a tile doesn't meant the rest is forgotten

This makes perfect sense to me and it would be very useful if we could establish just what happens from a dev, i.e. how many tiles get "cached" or pre-loaded as one travels along? Does it load the tile you're on plus the surrounding eight, e.g.
526
314
879

...because then we're potentially talking about at least 6k objects in RAM at once...

As I mentioned last night, I'm going to set up Windows Performance Log to track available RAM, File ops, PF usage and possibly significant also, Page Faults and see if anything jumps out.

Cheers, Rik.

[dlljones]

Hi Rik

My system details are as follows:

Windows 7 Home Premium Edition (64 bit)
AMD Athlon 64 X2 Dual Core Processor 4400+ 2.21 Ghz
Installed Memory 4Gb
ATi Radeon HD 4850 Graphics Card

Cheers

Llew

[Acorncomputer]

Hi

Can I point out that Windows 7 is not a supported operating system for RailWorks, so there might actually be a few issues when using it.

At the moment I am enhancing The Big Layout for RailWorks and it is noticeable that the RailWorks version has a much lower asset count per tile than the Rail Simulator version. I put this down to some of the RS assets being converted on transfer to RW into more frame rate friendly versions.

Note that the asset count at the bottom left of the screen does not take into account lofted items all of the time and I think it is fair to say that too many lofted items (short fences, short roads, etc) will cause as much trouble as too many normal scenery items.

On the whole, though. I would say an asset count of about 2000 per tile is the number to aim for.