Building Buildings

[18potterfan]

I am interested in trying my hand at making a few buildings. It'll be quite a long process since I have a lot of tutorials to watch and whatnot. I also have to figure out which program I'm going to be making them in, etc.

But before I started doing anything, I wanted to ask a few questions that I'm not sure if I can find the answers to in any tutorial. I'd like to get a good idea of what limits to expect when it comes time to do this for real.

1. How many polys/faces is the actual/absolute maximum for a large building?

2. How many polys/faces is IDEAL for a large building?

3. Would it be better to design "modular" parts or one large scenery unit? (by modular I mean make the main building, the "wing" buildings, the "bridge", the ramps, the platforms, etc.)
3a. If I did modular buildings, would I be able to get away with a slightly higher combined poly count than I would have with the singular large unit?

4. Would it be better to actually model the terraforming around some of the stations or should I make foundations that extend down far enough to do custom terraforming? (this is in terms of poly count/scenery in general. Idk if in-game terraforming affects performance differently than terraforming that is part of the buildings.

Any answers would be really helpful, even if they're only assumptions.

[jpetersjr]

It really depends on what your computer can handle for a large building, but say how I did my skyscrapers, you should definitely not try to 3d model each and every window and door. The best way to model a large building that will only be seen in the distance is to make a texture consisting of several floors.

Also for some buildings, such as a station sometimes it's easier to just build it in a couple parts rather then try to make it one complete building. Also, be sure to also not make it too difficult for a route builder to set up since if they can't set it up easily and quickly they probably won't use your building.

For a distant scenery building it is better to just build your building in one part but to also try to keep your detail to a reasonable level and make sure you delete any and all unseen faces since they will only slow the sim down.


...Cheers...


Big J

I will be looking forward to seeing if you can get this to work and to wish you luck.

If you have any questions you can ask me.

[wacampbell]

1. The answer is - it depends - on graphics card, on how important the structure is, and on what frame rates you will tolerate. Here's my guidelines - a scene ( everything thats visible at any one time ) should not exceed about 2 million triangles. For important locomotives, I might allow as many as 200,000 triangles. I like to see freight cars under 20,000. And for scenery buildings under 10,000 depending on importance. Now I suppose a signature station, where there is only one on the whole route, you might justify exceeding these limits - but that gives you an idea.

2. 10,000, more if its an important signature building. But most background buildings should be under 5,000

3. Generally modular parts are worth doing. You can assemble them using the component section of the blueprint, or just assemble them in the editor if you want. But a key optimization, is to reduce the number of texture files your building uses. I actually aim to use just one single texture file that contains all the various surfaces I need on a building. In most cases, a building that uses 2 texture files takes twice as long to render as one that uses one. 5 texture files takes 5 times as long etc.

3a. No, modular doesn't help you with frames rates. TEXTURE COUNT IS CRITICAL and PROVIDE LOW RES LODs if you care about performance. Of course if you are talking about a really gross model, well beyond the limits I am suggesting, you might be able to get that one million triangle pig to load if you break it up. But if you are doing realistic models, modular doesn't really matter. If you can re-use the pieces somewhere else, then go modular.

4. You rarely need to do the terraforming around a building unless you are trying to represent a very steep or complicated prototype site. Just provide lots of foundation ( I provide at least 1 meter below grade ) so you can adjust the terrain.

There are probably many other opinions - but after building 10 routes and over a 1000 models, these guidelines work for me.

Wayne

[jpetersjr]

As far as difficulty level I'd actually suggest starting out with a model such as a house, it's a good way to get used to a modeling program and also how to reduce your building on polygon levels.

As well, your textures also have to be in the power of 2 to work as well, about 512x256, 1024x1024 and 2048x2048 will suffice.



...Cheers...


Big J


Modeling is definitely not easy, this will be a hard learning experience, that's also why it will help to pick an easier model to learn on, a large building most likely won't be that.

[RailWanderer]

We all build differently, and use different software to model, but in all reality the basics are much the same. Building the model to the least number of polygons is best, and it is always a good practice to hunt down hidden polys as they will be the ones that give you trouble. In Max the wireframe mode helps with that. Trackside buildings should be the most detailed, especially those used by the user like stations, freight houses, docks and sea ports facilities, and those with animated loading and unloading. Always think in terms of what the engineer will see from the locomotive or from the local third person camera on the train. Roaming camera mode isn't that important as making things for use as simply scenery eye candy is just more the game engine has to draw.

So, if you can make a build at say 5000 polys, but know you can make it less, less is always better. I think one of the key processes of building models is to think them out before you attempt them. Personally, I try to make my models as one unit, but there are cases when you may want to make a certain design as modular to allow for flexibility in the use of several units to be combined to make different combinations that make different footprints. And with different textures, you can make those same modular units into other sets to be used by other route designers. Some people think that building a model quickly is always better than taking time to make a great detailed model with low poly count. Again, that is preference, but when it comes down to having all those assets showing in the sim, poly count is number one for keeping the framerate at its best. Remember, do yourself a favor and remove those polys that are below the ground terrain like the very bottom polygons that no one will ever see, and foundational extrudes always help when placing a building on irregular terrain.

Have fun!! 18 potterfan

[18potterfan]

Thank you so much guys!

I'm definitely going to start small, that's for sure! I want to get the basics down, not just with modeling, but also with understanding the textures and formats and files etc. I feel like that's going to take at least as much time to learn as it would a 3D software!

I have already built something in Sketchup that has I think just over 1,700 polys, but I went through and made a few different versions, each with lower poly counts. I wanted to see how happy I'd be with sacrificing more and more detail for the poly count. It was good to test my modeling skills since I'd only played around with repainting things like locomotives.

But I think I'm going to make the conversion to something like blender or 3DC because it seems that might streamline what appears to be an already tedious process.

[RailWanderer]

18potterfan, that's another point of building models that I totally forgot....LODs (Level Of Detail), which are just poly reduced objects or assets that progressively have fewer polygon and lesser texture definition as the distance increases from said object. The LODs are controlled as to when they change by using the Level, Distance, Name naming convention of each LOD (1_0050_Cube, 1_0100_cube; Etc.). The distance is what triggers the change in the LODs and texture Mip Map. So the concept is as you move closer to the object it gets more detailed and can be seen from a farther distance without placing a heavy load on the graphics engine.