[FRDF] Map slopes

[PJayTycy]

The map will also have slopes, with multiple steepnesses, i.e. 3,5,10,20,30,40 degrees, and so on
...
The map will have very gentle slopes with pretty much any angle (DD)

I think there should be a _limited_ varity in steepnesses. No more than ~5 diffrent degrees.
I also think that there should be fixed steps that the height of land have to follow. The steps should be 1/2 to 1/4 of the height of a car tunnel.

I see no issues here, this is the same right? Steep slopes however should not allow the player to build track upon. Possibly the player can build a bridge to span it or drill a tunnel through the hill which the slope belongs to.

don't give values for the slopes, but for the amount of height-units a tunnel or a house needs. In TTD this would be 1, in RCT this would be 3. There should not be any max limit on the height difference for 1 cell, so we can really create cliff-like landscapes too.

So, what do we say about the range of possible slopes ? Or how many height units do you want a train/tunnel to be ? How would this translate to the number of slopes we can have that allow tracks (eg: lower than 6% or whatever was decided upon) ?

[Zuu]

Maybe we can have a sortof lagaritmic set of steeepnes. So that there will be say 0% 2% 4% 6% 9% 12% 16% 25% 35%..

But that make it incompatible with the idea that there should be diffrent fixed heights of cells. So lets drop that idea for now.

Maybe we shall scale the height diffrent from width/heigt that PJaytycy writes in the scales deatured discussion.

• Vertical (height)
  • Vehicles height (trains, trucks, ships, ...)
  • Terrain slopes : This is a tough one:
    • Too much variation will cause weird views when you add buildings (they usually require flat ground to be build)
    • Too few variation and you won't be able to build tunnels where trains can pass through.
    • In TTD this is "solved" by using optical illusions for tunnels. I don't think that's a good thing to do, but probabbly the TTD-fans won't really mind.
    • In RT3 they use the same vertical scale for the terrain as for the trains. This means realistic tunnels are possible, but the grades look ridiculously steep (the benefit of this is, it's a lot easier to see and avoid them). They first tried to force all buildings to be on flat ground, which caused a lot of ground-reshaping when somebody built a new steel mill (especially problematic if you happened to have some tracks running there). Afterwards they changed it so buildings didn't deform the ground that much anymore, but instead were half-buried and half-floating (their midpoint was on ground-level). This solution made the players happy, because now the ground always stayed like it was, but made the eye-candy lovers sad, because of the many "visual glitches" (half-burried / half-floating buildings). I really don't have a propper solution for this problem, although 3DTT does a goed job by placing each building on a concrete foundation and puts the building at the highest height of the space it occupies.

If we use somthing like RT3 we can have fixed heght levels of cells, and still use the <=6% rule.

[Steve]

We need vertical walls for cliffs and such still. This very much depends on what kind of tiles and engine we're going to use.

When creating buildings that need flat land, put it at the height that will require the least moving of ground levels. So rather than at the highest or lowest point, the middle ish area will be cheapest.
Some buildings with multiple sections (parts of a steel mill) can also be seperated, so only certain parts need to be raised/lowered.

[Hyronymus]

Currently in the DD:

Sloped track can be laid if a (sub)class of track allows a sloped trajectory. The slope of a section of track is expressed in grades (°). The height difference between two ends of a track on a single, one-square section of track defines the slope’s grade.

Code: Select all

0.5 m rise – 1%
1 m rise – 2%
1.5 m rise – 3%
2m rise – 4%

Grades are also considered in speed and brake power calculations for vehicles going uphill or downhill.

There is a mismatch already: grades (°) versus %. But next to that there is no conclusion.

[eis_os]

Do you have something like buildonslopes?
Or will it possible to have two nearby tiles to be have different heights, then there is a automatic wall creation... (Like Locomotion). Ohh, and if there is a tunnel, if you can look in it. (because then you need special handling, so you don't see the wall part, and that really depends on the slope level, you will get more problems if you have gigantic steep slopes)


PS: Sorry about the short form

[Hyronymus]

Do you have something like buildonslopes?
Or will it possible to have two nearby tiles to be have different heights, then there is a automatic wall creation... (Like Locomotion). Ohh, and if there is a tunnel, if you can look in it. (because then you need special handling, so you don't see the wall part, and that really depends on the slope level, you will get more problems if you have gigantic steep slopes)


PS: Sorry about the short form

It's so short I can't follow through .

[XeryusTC]

Currently in the DD:

Sloped track can be laid if a (sub)class of track allows a sloped trajectory. The slope of a section of track is expressed in grades (°). The height difference between two ends of a track on a single, one-square section of track defines the slope’s grade.

Code: Select all

0.5 m rise – 1%
1 m rise – 2%
1.5 m rise – 3%
2m rise – 4%

Grades are also considered in speed and brake power calculations for vehicles going uphill or downhill.

There is a mismatch already: grades (°) versus %. But next to that there is no conclusion.

You can express gradiants in degrees and percents (RL correct, mathimaticly incomplete), 90° = 100% IIRC, which means that a 45° slope is the same as a 50% slope. Just FYI .

And trains should only be able to take a slope the same of lower as a max percentage, this can be decided per train. English trains could only cope with a lower gradient than other Europian trains in the past because the english wanted all the moving parts on the inside of the loc. Oh, and the slope should also be taken into account with physics (as Hyro mentioned before).

[Purno]

You can express gradiants in degrees and percents (RL correct, mathimaticly incomplete), 90° = 100% IIRC, which means that a 45° slope is the same as a 50% slope. Just FYI .

False. x% means a vertical increament of x meters on a horizontal piece of 100 meters. So, 45° = 100%. 90° would be unlimited %. It's not linear. But some tan formulas would solve it. It's true you can simply convert the two units tho. You can use ° in the code, while having % at the screen in the GUI, or vice versa.

[aarona]

You can express gradiants in degrees and percents (RL correct, mathimaticly incomplete), 90° = 100% IIRC, which means that a 45° slope is the same as a 50% slope. Just FYI .

False. x% means a vertical increament of x meters on a horizontal piece of 100 meters. So, 45° = 100%. 90° would be unlimited %. It's not linear. But some tan formulas would solve it. It's true you can simply convert the two units tho. You can use ° in the code, while having % at the screen in the GUI, or vice versa.

You are both right in different ways.

arctan(0.01) = 0.6 deg (1%)
arctan(0.1) = 5.7 deg (10%)
For small angles, the arctan formula is indeed linear.
The difference at a slope of 10% between the appropriate linear function and the actual arctan formula is 0.02 or 0.3%, which, is fairly close!

[Hyronymus]

But what do we want for the game, grades or percentages?

[eis_os]

Ok, I hope I can clarify my last post. The decision what slopes you want depends on the way tunnel entrances work. And this will aswell depend on if the engine will have Locomotion style walls between two tiles. Or more like TTD with buildonslopes.

Some examples:

Loco ike:
You have 10 slopes, it doesn't matter much if you use Locomotion Style tunnel entrances. Because your terrain provides much of the entrace. So you need simple a different Texture for the tunnel entrances with a hole in it.

TTD like but smooth terrain with cliffs:
You have 10 possible steep slopes where a tunnel can be build, you need for of the slope of the tunnel a texture at the right place of the hole. So the train doesn't hit a visible part. Or you need a tunnel model for each of the steep slopes. It really depends on the need how the tunnel is designed, say if you have a tunnel where you can't see the train passing in, you don't have a problem with the slope. I assume here that the steep slope feature doesn't have a small limit how much a "cliff" produces a height difference.

[Hyronymus]

The DD mentions we want track lying by drag & drop and have the path projected before constructed. At places where track encounters a hill or mountain it should choose between sloped track or a tunnel. Sloped track is "dragged" automatically, a player doesn't have to do anything for it. That's pretty much the way 3DTT worked and I think having tunnels as in 3DTT would work best for TE too.

Locked until the DD discussion arrives at this issue.