Atomic Systems

Hi Derek,

RSderek wrote:The terrain grid is the same as in RWs2. However with the self shadowing it makes a real difference to surrounding environments.

Count me really disappointed... I know there's lots of great stuff, but changing the grid would have made this release really awesome!

Can I take it that it's not being done because it's really rather hard to do with the codebase... or is it just that if you did so the game would run like a snail?

Ruth

And the cover of TRS2006, which I believe featured a 2MT 2-6-0.

Anyway, will SBHH finally be done away with to be replaced with more meaningful messages like "Rolling stock missing" (Or in my case, "Your computer is too lazy to run this route/scenario and has thrown a tantrum")

FoggyMorning wrote:http://en.wikipedia.org/wiki/Hitachi

Hitachi, Ltd. is a Japanese multinational corporation specializing in high-technology and services

Doesn't sound very British to me

Once they build their facility for the IEP production Hitachi will actually be the most British rail vehicle manufacturer these days!


I'm still not convinced about that alleged box art being genuine. In addition to being completely the wrong style (with items being scattered all over it in random spots, and US ratings), the image is straight off the IEP website. In my opinion the manufacturer would be more careful in controlling their image (Hitachi being a very professional company) until the IEP order is fully confirmed, especially letting it feature the Hitachi branding on the front.

Going back to the shadow maps, I think I've worked out what's going on. (This will get technical. Liberal Arts majors, you may want to look away now.)

Occlusion maps are a way to do shadows with multiple light sources without having to cast rays to surrounding geometry at runtime. Ambient occlusion maps are a special, simplified case of this which doesn't take light direction into account - it assumes the light comes from all directions at once, which is fine if it's predominantly coming from the sky but not the Sun. In RW2, ambient occlusion is used on loco and asset models to make them look better in all lighting conditions, but a stencil shadow is still needed for dealing with the main shadow cast by the Sun. Unfortunately, stencil shadows are too expensive to work with many light sources in scene, ie. at night.

But occlusion maps can actually be cleverer than this and take light direction into account too, and still be small enough to fit into a texture that wraps around a model. This is usually done using spherical harmonics, which can be thought of as a sort of angular Fourier transform. Just like with most audio compressors these days, you transform it and store just the most significant coefficients that fall out, instead of having to deal with all the raw data. So instead of having to render a full geometry pass for each light, you only need to pick the most significant lights for each object being drawn, and pass these to the clever maths in the fragment shader which looks them up in the occlusion map.

To deal with moving objects (ie. trains), a shadow map can also be built for each of these lights on-the-fly (this also requires a geometry pass for each light but it's a relatively cheap one). This allows trains to cast shadows on the landscape and other trains and other objects, and vice versa. It's just a more efficient replacement for stencil shadows.

By the sound of it, RW3 will have two somplete graphics engines: one lifted from RW2 which ensures backwards compatibility with older hardware, but requires stencil shadows on models; and the new RW3 one for everyone with new hardware which can cope with it. The good news is that with any luck, the new engine will require more from the GPU but less from the CPU, especially on new routes built with the instancing assets instead of individual trees. If true, this will let everyone recommend a relatively standard gaming setup (ie. spend about twice as much on the GPU as the CPU) instead of a business machine setup (ie. spend twice as much on the CPU as the GPU).

The downside of stencil shadows is that it requires adding geometry for it to the model. (This is actually unusual among game engines, usually the stencil volumes are auto-generated from the model itself.) Since people sticking with the old RW2 engine will tend to have older hardware which struggles with any extra work, you can sensibly stop adding stencil shadows to your models now.

The downside of occlusion maps - ambient or otherwise - is that they have to be pre-calculated, which takes a lot of CPU effort. Hence the "baking" process that RSderek often refers to, which is fortunately run by authors rather than drivers. With RW3, routes will need "baking" as well as objects, so that mountains (and less extreme geography) can cast shadows. I suspect that until a route is baked, the lighting model will fall back to RW2 standard - another reason why both graphics engines are included at once.

Baked route? how can you bake shadows on a route?

I assume the tool to do it is built into RW3 somehow. The terrain is just another (really big) object if you think about it, but the objects stuck on top of it will also be taken into account in the baking session.

crazyfrogbro wrote:Baked route? how can you bake shadows on a route?

You put it in the oven for ten minutes on medium heat.

Ruth, sorry you feel that way, but it is what it is.

As I have said a few times, everyone has their thing they want improved, but we have addressed what we feel are the most important areas.
A higher detailed terrain would be nice but it is not needed. There are many ways to create finer detail areas close to the track, both polygon and texture. Time has been spent on other aspects of the sim.

Regards Derek

good morning

i think we all should be pleased with the update.
there is something for everyone in there.

over the years we discussed so often about many improvements, and now they are ready for us.
i personally think that the terrain mesh is detailed enough.
from september on we get the most beautiful train simulator on the market, at least for me it is.
i always watched a little bit jealous to the other games, they had nice shadows and lighting effects, things that
are important for a realistic environment. and now it's the first time that we get those effects
in a train simulator. can there be something better?


greetz

Rail-X

One thing we should all remember is that it is free! Maybe it's not free enough for somepeople!

Well, it's free if you own it already new owners are going to be paying for product still.

from september on we get the most beautiful train simulator on the market,

Perhaps that should read "We hope we get...

On the other points, I don't think terrain mesh was ever on the agenda this time round. I agree that it is still too course though not as bad to work with as the ground in MSTS, converesly if you create a route in one of the later Trainz versions using the finer mesh there can be a bit of a performance hit. I certainly think like MSTS, it should be possible to define a smaller resolution (I think it was called error bias in MSTS) around cuttings, embankments and rivers etc. to avoid the sawtooth effect which even judicious use of the smooth tool can't always eliminate.

Kariban wrote:Well, it's free if you own it already new owners are going to be paying for product still.

Then really they should be the only ones complaining I guess!

Shouldn't it read... the upgrade will be free to existing users - provided that you don't have to upgrade your hardware to take advantage of it.

glowball wrote:Shouldn't it read... the upgrade will be free to existing users - provided that you don't have to upgrade your hardware to take advantage of it.

Nope.