Graphically Destructive?

[bravedan]

Hi!

Try this one for size.

I have a loco under way which has five graphics files. The masters are held in TGA format and are 512x512. Four have alpha channels, and one of these has a wierd problem.

It works OK on the loco model in the Sim with colors set for the BR lined black livery variant.

However, change the base colour for Crimson Lake and you'll get a "cannot add car to world" error on loading it within the Sim, followed by the send/don't send screen of death........!!!!!!!!!

This is 100% repeatable beyond any doubt......all you have to do to get a crash is change an area of the graphic sheet from RGB 32/32/32 to 81/7/8.

I have gone back and started a new file from scratch......same result.

Doctor, my brain hurts...............................

Dave

[CaldRail]

5 files? All of them 512 squares? Why on earth do you need to use so much texturing?

[bravedan]

Mmmmmm, your tone clearly indicates you consider 5 files excessive, yet it's actually low for the degree of complexity required, and if you want detail and good lining on a steamer, you need the pixels.

Or shall I just get my Spectrum out again?

However, the point is........why does a change of colour attribute, which does not increase the overall file size, and anyway is used in other files in the set without problem, crash the Sim??

[mikesimpson]

I can not prove this, but I think MSTS does have a problem with 5 .ace files for a model.

While helping Neville Brooks testing the NZ route, he has a model in there, seedstore.s with 5 .ace files. This works fine, but if you compress just one of the .ace files it fails to load.

I thought this might be caused by the heavy amount of scenery on the tile, so I moved the shape to the MSTS test route and stuck it on an empty tile, but got the same problem.

[CaldRail]

Mmmmmm, your tone clearly indicates you consider 5 files excessive, yet it's actually low for the degree of complexity required, and if you want detail and good lining on a steamer, you need the pixels.

The subject of huge texture sizes has come up frequently before. It simply isn't necessary. I'm willing to bet that the vast majority of your pixels are nothing more than background colour (please correct me if I'm wrong) which would be a colossal waste of resources. Now I freely admit I'm not an expert in 3D modelling but yes, 5 x 512 x 512 IS excessive however much detail you're after. The sort of modelling that MSTS uses obliges us to get what we can for a minimum of polygons and pixels. I do realise that everybody likes detail (I've been told that often enough!) but please remember that video memory is not a bottomless pit. Your loco will have to share texture space with everything else - rolling stock, static scenery, and all the terrain textures from the world tile and its surrounding eight tiles. Windows, MSTS, and probably several smaller programs all need to be loaded as well. In fact, it is quite possible to provoke a crash simply because the texture space (video and normal memory) is in conflict with the needs of the programs running in the background. Also, the fact is your loco is loading and unloading a huge amount of information which will impact on your frame rate.

So what can you do about this? Well, wherever possible use the smallest area of a texture for a given polygon. For instance, if a set of handrails is all one brass colour, then a small 3x3 area is enough to texture the whole lot no problem. Stretching a narrow area can cover a boiler.

Ok, I understand that some locomotives liveries can be complex and fussy. Fair enough, but with careful use of parts, repeated textures, stretching, even 'plaques' (logo bitmaps with transparency) you can seriously reduce the overhead on your PC. Its worth the effort.

[bravedan]

Thanks Mike for info..............

Re: "Stretching a narrow area can cover a boiler." from Caldrail......Yea, right.......so you then apply rivet lines, boiler bands, inspection access panels, washout plugs, panel jointing, lining, not to mention shading and weathering, all by Plaques??? This I gotta see...............

Actually I agree in principle with most of your last post, and we do already use small colour "swatches" and stretch them wherever possible.
However, a steam loco with lined steps, footplate, cab (extending to cab roof) and boiler is what we are talking about here.

OK, this may be pushing the Sim hard, but frame rates are very good, and the loco (in black) runs quite well even on my test "minimum" system, which has only a motherboard Intel graphics system and now ancient processor!! (Yes, I do test and try to tune the things you mention...........)

And now......back to the point of the post............

Changing ONLY an area of the sheet from 32/32/32 to 81/7/8 causes the crash, it's totally robust with the Grey/Black, but crashes with the Maroon......repeatable............reversible.........

Same number of pixels, same sheet size, same build process, actually a lower number of colours used on the sheet, same colour used on other sheets on same loco without issue........

Now, if it was rejecting G*R green, I could understand it!!!!!!!!

Regards,

Dave

[Zorcan]

Laying down the law as to the number of textures a modeller should use strikes me as being unnecessary and unhelpful.

I think that anyone who has seriously used MSTS will understand that high polygon counts and texture areas will hit the frame rate. The processing poser available will determine how big a problem a particular model will reperesent.

It is quite wrong to suggest that, all things being equal, there is no way you will achieve the same degree of detailed rendering with 2 x 512 sq images as you would with 4 or 5. I won't bore everyone with the technicalities of why this is so, but for one thing "background colour", properly used, is rarely solid, for another you do need relatively large images to properly depict lining, numbering, name plates, crests etc. etc.

The bottom line is this - if you have limited power and want high frame rates then make/use simpler models. If however, you want the maximum degree of detailing and realism you can achieve, then you have the option to use/make more elaborate ones.

This is a matter for personal choice. There are plenty of models available for free download, spanning the entire range of complexities, so deciding which suits you is quite straightforward.

[Zorcan]

BraveDan,

Sorry that your post has been "Hi-jacked". My latest model uses 4 512x512 textures - 3 with alpha. Whilst I was working on it, the ubiquitous "blank.ace" was also involved, making 5 in all.

I have never experienced your problem. I use TSM 1.0.

[megatron]

my 175 has 10.ace files with it .....
but thats just me being a novice and partly lazy and not putting them all together to make 3 full ones.
The majority of them only have one area which is used!
No ones complained yet..... (touches wood v.quickly!!!)
The blank.ace thing is when you've not textured all of the polys in TSM. I forgot to do that a couple of times and got the blank ace thing. Just use the untextured poly checker to see

[qzdcg8]

I use 4 256x256 ACE files in the Blackpool Trams - with these, you can't use any duplicated textures on the exterior since they can be painted in just about any unique way possible. As it happens I can't use anything BUT 256x256 ACE textures in my TSM???

[CaldRail]

If you use version 1.0 then 512x512 textures should work.

Er.. Laying down the law? No, just trying to get people thinking on how to approach a project with an aim to getting the mostest from the leastest. I can't stop anyone from using massive textures nor multiple massive textures if thats what they choose to do. I disagree with the principle that you need vast amounts of texturing to detail a model, thats all. (CaldRail slinks away to seek medical aid for his burns... )

[David101]

Another strategy that works well (at least with coaches) is to share a texture between several models. After much agonizing, I decided to go with 1024 X 1024 textures for my ex-LMS coaches. I compensated for the huge size of each texture by sharing it between 5 different models. If all 5 coaches are loaded, this is actually more efficient than each coach having a single 512 X 512 texture. On average, however, it is probably slightly less efficient, since it is unlikely that all 5 coaches sharing a texture would appear in one train.

[bravedan]

Getting weirder by the minute...............

I have now proved that the colour 81/7/8 can be applied to the "suspect" sheet, additionally to all existing shades, and not cause a problem............BUT......one (large) area of the sheet is by many trial and error changes still off limits.........add that colour there (actually footplate edge area of the model) and the Sim crashes, change it back and it's happy...................

Bit like the old Commodore "Pet" desktop, where if you poked a memory location with a certain value you could actually blow up a chip.......so you could actually destroy the computer by a simple keyboard command!!!!!!!!.............Oops, showing my age..............


Dave

[duckweed]

Dave, have you tried other colours just slightly off the one causing the problem? I have 5 texture files on some of my locos and no problems, so I don't think it's the number of files. I just can't imagine why changing a colour should make it throw a wobbly. How are you changing the colour? Are you manually altering lines in the tga file?

Regards,

~Terry~

[Zorcan]

Caldrail,

Fair enough - but can you point me at just 1 typical loco which is well detailed and only uses 2 off 512x512 textures ?

Now there are 2 highly subjective terms there which could lead us into more debate - typical and well detailed.

By "typical", I mean something more sophisticated than an unlined 0-6-0.

By "well detailed" I mean to avoid texture blurring for all but insignificant details.

Oh - I guess "insignificant" is equally subjective

If I could figure a way to use less textures for a given result, believe me, I'd go for it.