Terrain modeling in CMx2

[Battlefront.com]

Since I've seen a lot of questions about terrain, I figure a quick compare/contrast with CMx1 is in order.

In CMx1 we had a fixed grid of 20m x 20m. This grid determined both the terrain data as well as the graphical appearance. We called these 20x20 spaces "tiles". CMx1 resolved the location of a unit down to fractions of a meter within a tile, however all units within that tile were treated as being in the same terrain regardless of position. Well, except for a few hybrid tile types, such as roads and small houses (i.e. things that were not 20x20, but instead contained within a 20x20 tile). The relative position mattered for LOS/LOF, explosions, movement etc. and therefore it did matter what your relative position was.

In CMx2 things are very different. The CMx2 concept of tiles is gone. However, there is still an underlying grid and a separate terrain mesh. Unlike CMx1, the two can contain different sized blocks. This allows us to independently control the volume of data for the game engine and the graphics engine. Say for example we find that the game data is a real pig in terms of RAM and CPU usage, but the latest graphics hardware can handle the graphics just fine. Well... we can tweak the fidelity of the terrain mesh without increasing the size of the blocks for the underlying game grid. Or perhaps it is the other way around... the CPU and RAM can handle more game data, but the graphics bottlenecks require a lower resolution of the graphical terrain mesh, so we increase the fidelity of the underlying game data. Whatever the case is, the sizes of these blocks can be adjusted by us, quite easily, as hardware becomes more powerful in years to come. That means we're not locked into one way of doing things for the next x number of years.

Why not just resolve everything down to individual pixels and be done with meshes and blocks of terrain? Hardware limitations. Unless we employ pathetically small maps with simplistic units this is just not possible. That means a certain amount of "grid" behavior will continue to exist for some time to come. Good news is that over time the grids will be smaller and smaller.

What does this mean in terms of making realistic looking maps in CMx2? In no particular order...

1. The grid size is now 8m x 8m vs. CMx1's 20x20m.

2. Now even an 8x8 item can be put at a 45 deg angle, unlike CMx2 where 45 deg angles were only possible if they were smaller than 20x20m. This allows you to have, for example, a row of adjacent "row houses" running at a 45 deg angle to another row. This was not possible in CMx1 because diagonal lines never allowed things to be truly adjacent.

3. Terrain is in layers, allowing you to mix and match stuff within the 8x8 areas. This was only possible in CMx1 if we had hand coded the 20x20m tiles ahead of time. We still have to limit how much stuff you can pile up in one spot for code reasons, but it is possible to do more combos than was possible before.

4. Because the grid is now 8x8m, you can pack a lot more terrain features into a smaller space. For example, in CMx1 you could have a house on grass as one of the 20x20m tiles. Now you can have a 8x8m house with trees around it, or a wall running right up to it on one side and a road right along on the other.

5. Problems inherent to the 20x20m terrain mesh are most likely all solved. Things like not being able to have a house in the side of a hill... no problem now. I'm sure there will be some limitations here and there, but not the routine ones experienced by map makers in CMx1.

6. Buildings are so different from CMx1 that I'll have to start up another discussion about them. Suffice to say that we designed buildings with urban warfare in mind. Yes, that means you can have dense, multi-story structures with roof access, basements, specific entry/exit points, and a host of other features. Graphically buildings will look a lot better than CMx1, though they won't match the sort of fine details seen in games like BF2. That's the trade off one gets for flexibility... function over form

Oh, probably lots of other things, but I think I've hit the high points.

Steve

[ August 25, 2005, 07:20 PM: Message edited by: Battlefront.com ]

[Andreas]

Sounds excellent.

[jim crowley]

Superb!

To what extent will terrain be deformable? I'm thinking particularly of the "indestructible" walls and fences in CMX1.

[Sergei]

Steve, that sounds cool. Especially #2 and #5. However, may I ask, could not at least the roads (or other such linear forms of terrain) be made non-block based? Well, I suppose not, because otherwise you'd have done that.

QUESTION

Can you think of any automated way to utilize old CM maps as a basis for CMx2 map? Let's say, for example, if you allow grayscale BMP's to be imported as heightfields (there's a utility which allows 'Mapping Mission' maps to be exported as a .BMP files, so it'd require just stretching the file to get the basic contours done) - not to mention that the possibility to import heightfields would be useful for other purposes as well.

[Sergei]

Have you seen Mapping Mission, anyway? Do you think that any features from would be taken to the new map editor (like auto-drawing roads/walls/fences, or having pictures of maps as backdrops)?

Also, in CMx1, if you place a building in a tile that doesn't allow buildings, it simply won't be displayed. Could this kind of stuff be shown right at the Map Editor display in CMx2?

[76mm]

Thanks for the info, sounds like a big improvement.

I have one question though--all of the new detail, especially for buildings, makes it sound like it will be absolute hell creating any large maps, particularly something with lots of buildings--creating multiple entry points for every building alone would probably drive me crazy...

How will it be possible to create maps with the new 8x8 grid without spending ungodly amounts of time?

76mm

[Sergei]

Not that hard.

This is what Rune's new Stalingrad scenario will look like.

[Jack Carr]

This sounds great!

[securityguard]

This is an unbelievably massive improvement, sounds like a map makers dream come true.

Does the new map engine have a limit of tiles?

[Salkin]

Steve Rocks !

(posts like this probably makes Steve ignore any and all sugestions I may have )

//Salkin

Shameless fanboy

[dalem]

Originally posted by securityguard:

This is an unbelievably massive improvement, sounds like a map makers dream come true.

Does the new map engine have a limit of tiles?

Yes, four.

-dale

[Philippe]

This is probably the wrong place for this, but I hope this means that fortifications like bunkers and pillboxes (what are wooden pillboxes, anyway?) can be treated as terrain that gets moved into, used, and moved out of -- rather than as a unit.

If my squad happens by a previously abandoned concrete bunker that is facing in the right direction, the concrete makes great cover even if the machine gun/anti-tank gun is out of action. Same goes for whatever those wooden pillbox things are supposed to be. The guys defending it should panic, grab their machine gun, and abandon that weird piece of lumber. But later on it should be possible to reoccupy it, even if it is shot full of holes.

And it has always annoyed me that I can't figure out the firing characteristics of the inherent machine guns/anti-tank guns of a fortification.

So can we have proper entrenchements, foxholes and trenches that actually make a dent in the terrain?

Can we have built-up firing ramps as independant terrain so that dug-in vehicles don't have to spend the entire scenario immobile? I never dig in my tanks -- but I would dearly love to play a shell game with a fast tank and a few pre-prepared firing positions. Unfortunately the only historical example that I can think of off the top of my head are the old Israeli defenses along the Suez canal. But I'm sure they had things like that in WWII.

And yes, I want the Maginot line ! I want multi-layered underground forts with many layers of sub-basements. And the reason I want it is not to play Maginot line scenarios, but for the eventual WW I fort-storming scenarios. I want to see a whole expansion pack built around Verdun !

I'll be quiet now.

[Mace]

Great stuff (especially layers), however I'd be interested to know of the improvements made to the actual terrain builder interface as well.

For example, In CMx1 one had to place 100 tiles to populate a 200x200m square area, and doing that and then adding the elevations was somewhat clunky.

With the new engine the builder would need to place at least 625 tiles (at 8sq mtrs a tile) to populate the same area, and that's not including the placing of additional components added through the other layers.

So it's my guess builder interface itself has been improved to help expediate the process?

[juan_gigante]

Yes! This r0ck0rz! Especially the layers.

I do wonder how fortifications will work. I think they are similar enough to terrain to be mentioned in the same thread, so I ask the BFC gods: how different will fortifications be?

[Battlefront.com]

Glad you gusy like it so far! Here are some quick answers...

Fortifications are terrain now. They are simply a structure that can accept certain units or not.

The map Editor is not done except as it exists on paper. The concept I have should make it easier to make large maps than CMx1. However, dense urban maps will likely be more time consuming to make. But that is the tradeoff one must accept. CMx1 was extremely simplistic so it was fairly easy to put down buildings. Everybody wants more complicated structures, and that means more effort on the part of the builder. I've got the UI about as slick as it can be, I think, but there really is no way to have CMx1 urban creation simplicity without simplistic structures.

Terrain is deformable... cripes, I can't believe I forgot to mention that! I'm not exactly sure how far we'll take this in CMx2's first release, but buildings will be deformable visually as well as structurally. I think walls and fences should be no problem too. More details will have to wait for another day.

We have no plans on making any sort of import tools for CMx1 maps. Far too difficult and not a good use of our time.

Roads and other linear things must still conform to the grid. You can not freehand them. This is for code reasons, in particular LOS which absolutely hates creativity

Steve

[JonS]

Originally posted by Battlefront.com:

Fortifications are terrain now. They are simply a structure that can accept certain units or not.

Splendid. I sensed you had your tinfoil hat off for a while. The mind control rays obviously worked.

Splendid. Splendid splendid splendid.

Erm, presumably, despite them now being terrain, players will still be able to 'buy' fortifications?

[juan_gigante]

I re-read that part about buildings... so will each little building we place have its own entry-exit, etc.? Or will all "small diagonal house type A"s have the same points? Or will we be able to set them ourselves?

This is all so cool.

[Tarkus]

I must say I read every bit of this particular thread with immense joy. I really sounds promising. Flexibility, functionnality, more powerful tools. This sounds good. Can't wait to see glimpse of actual capabilities of this engine.

Cheers

[Pzman]

Yes it does give the impression of more creative maps and terrian. Even if roads have to stick to the grid, that does not mean they cannot be more flexable than they are in CMx1 though.

The thought of having to put entry + exit on houses does have its downs for the creator, but will create more challenges when playing. So a map will take a little longer to create than it is in CMx1, not a big deal in my books.

[Battlefront.com]

Players can purchase fortifications. The scenario designer can also designate some of them to be instantly spotted, so as to simulate pre battle knowledge. That means no matter where the defender places them, the attacker will know exactly where they are all the time every time. The defender, however, won't be aware of this I'll post an expanded tidbit in its own thread.

Building details... that will have to wait until I start up another thread. I'll try to get to it tonight. Short answer is... there is no short answer

Steve

[Pzman]

Steve the bit about known enemy fortifications sounds great; something I think we really missed in CMx1, that is without putting text on the pillboxs location, and padlocking it.

[Delyn]

Originally posted by Battlefront.com:

The map Editor is not done except as it exists on paper. The concept I have should make it easier to make large maps than CMx1.

Could you explain this concept of yours?

Would it include using larger "tiles" when needing to cover more ground? 16x16 32x32 64x64?

Keep in mind I am not familiar with the CMx1 Map Editor.

[Battlefront.com]

We'll just have to see what Charles let's me get away with I can say that the Editor will still be in 2D. We wanted to do a realtime 3D Editor... but that is a heck of a lot of coding and testing time (I've worked on these in a "past life"). Every minute we spend coding the Editor is one that is not going into the game itself. Since CM is marketed as a game and not an editor, obviously we need to keep our priorities straight

Steve

[Pzman]

As much as the 3D Editor would be nice/great, the thing that costs you guys less in that regard will always be best. After all the editor is a kind of freebie expansion pack.

[Bigduke6]

Steve,

Thanks very much for listening. You guys amaze me at how well you understand where your customers are coming from. If only the rest of the world was like you...

How will cover density work? If you take the example of trees, will the density be limited by the type of trees you can plop down, same as before? (Scattered woods here, regular woods there). Or is there going to be some way to toggle/slide bar the density?