New bridges (bridge-castle-transitions, hanging bridge)

[homunculus]

Idle query: Could we have an invisible bridge terrain type plus a set of halos? I'd love things like a multi-hex Indiana Jones style bridge, or a multi-hex grand bridge several hexes wide. But shoehorning them into WML is horrible at best often impossible. If they were just halos, all you'd need is some generic bridgeheads, and then you could really go to town on the artwork without having to bend over backwards to accomodate the limitations of the map.

The WML is not a problem. The problem is that every different length of bridge requires its own complete image. In other words, if you want to support up to 6 hex long bridges, you need 18 complete bridge images drawn (with different radii of curvature - no recycling). If lurker wants to do that, cheers...

This is not very strictly correct, as far as I understand.
Geometrically, the hanging bride is a parabola, and therefore the center of the parabola can be extended in the ends to get a longer bridge.
Which means that the shorter bridge can be recycled as the center of the longer bridge.
Or rather, only the longest bridge would need to be drawn, and both ends cut off to get all the shorter bridges.
(Edit: The even and odd length bridges can both be cut from the longest bridge, unlike I wrote earlier)

As for the railing ropes (that could actually be an effective construction element), there might be a problem if it is desired that the closer railing should appear on top of units, because some units might be too large.

[doofus-01]

This is not very strictly correct, as far as I understand...

It's correct enough, since the parabolas are not the same or else there is an offset problem, as discussed above.

Unfortunately, no. We can have different offsets for different terrains (so the n-s bridges could have no offset), but we can't really do it on a per-tile basis. In theory we could of course split the bridge from 3 terrains into 6 or 9 (3 terrains for the midsection parts, 3 or 6 terrains for the end section parts), but that'd be way too annoying to deal with in the map editor, so I think that option is pretty much off the table.

I agree. That brings us back to some sort of support. Here is a proposal with a very weak pillar standing on the ground.

The attachment hanging4.png is no longer available

How does that look on longer bridges? I think it might be too undulating, unless you interspersed it with longer sections between pillars.

Did you not like the rope railing? It may look odd for some units, but a firedragon on the rope bridge is going to look silly no matter what. Example using my version because it is what I have, it could be better but maybe it helps:

WML:

Code: Select all

#define ARCH_ROPE_BRIDGE_NW1_LF TERRAINLIST ADJACENTNW1 ADJACENTNW2 ADJACENTSE1 ADJACENTSE2 LAYER FLAG IMAGE
    [terrain_graphics]
        map="
,  .,  .,  . 
3,   .,  .,  .
,  2,  .,  .  
*,   1,  .,  .
,  *,  4,  .  
.,   *,  5,  ."
        [tile] 
            pos=1
            type={TERRAINLIST}
            no_flag={FLAG}
            set_flag={FLAG}
        [/tile]
        [tile] 
            pos=2
            type={ADJACENTNW1}
            no_flag={FLAG}-nw1
        [/tile]
        [tile] 
            pos=3
            type={ADJACENTNW2}
            no_flag={FLAG}-nw2
        [/tile]
        [tile] 
            pos=4
            type={ADJACENTSE1}
            #            set_flag={FLAG}
            no_flag={FLAG}-se1
        [/tile]
        [tile] 
            pos=5
            type={ADJACENTSE2}
            #            set_flag={FLAG}
            no_flag={FLAG}-se2
        [/tile]
        [image]
            layer={LAYER}
            name={IMAGE}.png
            center=144,180  
        [/image]
        [image] 
            layer=25
            name={IMAGE}-rope.png
            center=144,180
        [/image]
    [/terrain_graphics]
#enddef

{ARCH_ROPE_BRIDGE_NW1_LF *^By\ (!,*^By\) (*) (!,*^By\) (*) -80 overlay bridge-rope/wood-se-nw}
{ARCH_ROPE_BRIDGE_NW1_LF *^By\ *^By\ (!,*^By\) (!,*^By\) (*) -80 overlay bridge-rope/hex-b}   
{ARCH_ROPE_BRIDGE_NW1_LF *^By\ (!,*^By\) (*) *^By\ (!,*^By\) -80 overlay bridge-rope/wood-sag-nw}
{ARCH_ROPE_BRIDGE_NW1_LF *^By\ *^By\ *^By\ (!,*^By\) (*) -80 overlay bridge-rope/hex-c}
{ARCH_ROPE_BRIDGE_NW1_LF *^By\ (!,*^By\) (*) *^By\ *^By\ -80 overlay bridge-rope/wood-sag-nw}
{ARCH_ROPE_BRIDGE_NW1_LF *^By\ *^By\ (*) *^By\ (*) -80 overlay bridge-rope/wood-se-nw}

The fraction of it that I got done is in Archaic_Era on 1.9 add-on server.

[Boldek]

Maybe you should have it so that flying units like drakes play their flying animations when on bridges to avoid large bulky critters. Though I don't think the fire dragon has a flying animation.

[lurker]

I tested the "wobbly" and the "straight" version with longer bridges. I think none of them are really acceptable. I will try to make a new version (a little wobbly, with more than one support per hex transition). But just to show I am still working on it:

hanging5a.png (319.94 KiB) Viewed 4725 times

hanging5b.png (295.95 KiB) Viewed 4725 times

About ropes: I am not a fan of them. If they turn out to be necessary for the bridge to look natural I will add them, but first I have to get the basic shape right.

[Zerovirus]

One way to deal with the fire dragon's problems on many cramped terrains might be to give it a custom movetype and just give it unwalkable on bridges or something.

Nothing to say about the rope bridge- keep up the good work!

[SFault]

About ropes: I am not a fan of them. If they turn out to be necessary for the bridge to look natural I will add them, but first I have to get the basic shape right.

Maybe there could be more support at the ends of the bridge. Especially longer ones look bit unrealistic if they are just "floating" in the air. Maybe longer support poles?

[homunculus]

This is not very strictly correct, as far as I understand...

It's correct enough, since the parabolas are not the same or else there is an offset problem, as discussed above.

Was aware of the offset problem, but I don't see it as a real problem because, as far as I can see, looking at the shots with the hex grid and also the shot with the lieutenant on the bridge with one foot in the air, the bridge could hang considerably lower.

On the other hand, it seems that the bridges (all, not only the hanging one) seem to be drawn as if units were standing in the center of the hex, while the units are not really standing in the center.
And I am not sure if moving all bridges from the center of the hex to where units really stand would be a good idea.

[zookeeper]

That seems like a very good idea to me. If lurker wants to try that approach, we could have a winner.

[lurker]

Maybe there could be more support at the ends of the bridge. Especially longer ones look bit unrealistic if they are just "floating" in the air. Maybe longer support poles?

That does indeed look quite good. I tried it out with a little smaller poles.

hanging6a.png (161.56 KiB) Viewed 4415 times

It works, visually, with the straight middle part, but only if there is no other such bridge with different length near it. Perhaps that is a limitation we can live with.

Next I tested how the bigger end pieces interact with units:

hanging6b.png (102.06 KiB) Viewed 4415 times

I think, if I shift the bridge one or two pixels up, and make a dedicated end piece for water (which I should anyway), that could work, too.

[Coffee]

Geometrically, the hanging bride is a parabola, and therefore the center of the parabola can be extended in the ends to get a longer bridge.

Actually it is a hyperbolic cosine. You can see the function plotted on a calculator with the "cosh" function.

[homunculus]

Actually it is a hyperbolic cosine. You can see the function plotted on a calculator with the "cosh" function.

cosh_vs_parabola.png (5.68 KiB) Viewed 4095 times

I would "prefer" the parabola (red). Edit: Confirmed again, looking at my key chain. Whatever way I hang it, 'tis a parabola.

. o O (Was pointed out something a little while ago, and reread my crits and responses, and it seems my crits are sometimes understood as some kind of a wish list. Well, that is not the intention, rather it should just be a different point of view. In this case, seeing what the discussion is about here, I don't think it would be a good idea for me to plot the function and skew it in graphics editor to get the guides.)

[Coffee]

I would "prefer" the parabola (red). Edit: Confirmed again, looking at my key chain. Whatever way I hang it, 'tis a parabola.

I was just pointing out a geometry fact. I don't mean to be rude or bring this off topic, but I think you you don't understand yet how scaling works. You have 2 parameters (a and b) to change in the function y = a cosh(b x) and can get a whole different range of "bridges", rather than just the one you plotted.

Might be a good idea to see Simple suspension bridge and Catenary (or hyperbolic cosine shape). Have a look at the chain and footbridges there and don't get confused with the full suspension bridge, which has an (almost) parabolic shape in the chain section (as it supports the walking path via vertical cables strung to 2 pillars on either side and is a very different bridge from the ones here).

[homunculus]

lots of chat, little constructiveness:

[...]I think you you don't understand yet how scaling works.[...]

Do you really, with a straight face, believe that I cannot scale a function, and do you really believe that I didn't try range -1 to 1 first, where the parabola and the cosh are indistinguishable to the eye?
Even if you somehow do, how can you be so certain?
When you look at the plot, don't you notice how 5**2 is not really 73?

Heck, people are saying unit offsets is a problem, but no one seems to try to figure out what the exact limits are.
And the ropes at the posts look decorative and do not look like they are supporting anything.
And the railings would help to stabilize the bridge by bringing the center of mass comparatively lower.
And whatever, but if the bridge looks workable for most people and all is well and good, does all this matter too much?

There is a reason for saying it is a parabola, just like there is a reason for saying that a sphere that is lit from south-east can be shaded by a radial gradient.
So, instead of trying to figure out why I am saying it is a parabola, you get convinced that I cannot scale, I find this a bit intriguing.

"superficially similar in appearance to a parabola" is what your link says.
You suggest to scale cosh so that it becomes a parabola, I suggest to use a parabola.
Of course you are correct (in fact we are talking from a different point of view), just like you would be correct if you said a sphere cannot be shaded the way I suggest (for drawing purposes), but somehow I feel this should continue in pm, if at all.

Edit: Trying to fix the post. I don't know if this suggestion is useful or not, but it is better in constructive form nevertheless.
In math speech, it would perhaps be correct to say that a parabola is a good approximation to catenary, in fact I find it visually indistinguishable, and even more so at the scale of Wesnoth terrain.

red line--parabola; blue line--catenary

catenary_vs_parabola.png (3.74 KiB) Viewed 3830 times

Using a parabola, only the longest bridge would need to be drawn in the three directions, and then cut to reusable pieces, meaning that the shorter bridge tiles are reusable as the center part of the longer bridge.
Also, it seems that making the ropes at bridge ends look more like they are supporting something, can be done by changing angles at the points where the ropes meet the bridge (rather than continuing the curve of the bridge smoothly at that point) and this way also the ends of the bridge could become reusable for all bridge lengths.

ends.png (706 Bytes) Viewed 3830 times

I see two problems with this:
1) The curve would look better if the longest bridge can hang low enough. This comes to how much a unit can be offset lower in the tile (I don't think this is a peanut decision). Though in the latest images of the shortest bridge, I would say the bridge seems to be hanging very loosely and much less curve would be sufficient.
2) The bridge being curved along the whole length or being flat in the center is largely a matter of preference. Myself I would be using the hanging bridge with the flat center in the latest images without hesitation if I needed such bridge in a campaign. I just think that curved along the whole length would be slightly cooler.

I think a curved bridge with reusable tiles could be done, if that is desired.

[lurker]

Hello,

@homunculus: The graphics are not the problem, whether reusable or not. The problem is the units' offset which is the same for the whole length of the bridge. Therefore the bridge cannot hang lower at the center than on the sides.

Here is the bridge. As already mentioned, it works best if there are no bridges with different lengths in the same scenario, unlike the following shot:

Greetings

Lurker

Edit:

I also attach the images and the WML.
Supposedly the bridge should use the bridge macros from mainline. But after another look at the multitude of images needed for that I decided to come back to my original cutting and tried to refine the WML behind it:

Spoiler:

Code: Select all

#define NEW:TUPLE_SE_NW_L SE_TERRAIN_LIST NW_TERRAIN_LIST N_TERRAIN_LIST S_TERRAIN_LIST LAYER IMAGE
   [terrain_graphics]
      map="
, 3
1
, 2
4"
      [tile]
         pos=1
         type={SE_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=2
         type={NW_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=3
         type={N_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=4
         type={S_TERRAIN_LIST}
      [/tile]
      [image]
         center=63,126
         layer={LAYER}
         name={IMAGE}.png
      [/image]
   [/terrain_graphics]
#enddef

#define NEW:TUPLE_SW_NE_L SW_TERRAIN_LIST NE_TERRAIN_LIST N_TERRAIN_LIST S_TERRAIN_LIST LAYER IMAGE
   [terrain_graphics]
      map="
3
, 1
2
, 4"
      [tile]
         pos=1
         type={SW_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=2
         type={NE_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=3
         type={N_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=4
         type={S_TERRAIN_LIST}
      [/tile]
      [image]
         center=63,94
         layer={LAYER}
         name={IMAGE}.png
      [/image]
   [/terrain_graphics]
#enddef

#define NEW:TUPLE_S_N_L S_TERRAIN_LIST N_TERRAIN_LIST W_TERRAIN_LIST E_TERRAIN_LIST LAYER IMAGE
   [terrain_graphics]
      map="
, 1
3, 4
, 2"
      [tile]
         pos=1
         type={S_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=2
         type={N_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=3
         type={W_TERRAIN_LIST}
      [/tile]
      [tile]
         pos=4
         type={E_TERRAIN_LIST}
      [/tile]
      [image]
         center=94,108
         layer={LAYER}
         name={IMAGE}.png
      [/image]
   [/terrain_graphics]
#enddef

#define NEW:BRIDGE_MAIN_L BRIDGE_SE_NW BRIDGE_SW_NE BRIDGE_S_N N_TERRAIN_LIST S_TERRAIN_LIST LAYER IMAGE_GROUP
   {NEW:TUPLE_SE_NW_L {BRIDGE_SE_NW} {BRIDGE_SE_NW} {N_TERRAIN_LIST} {S_TERRAIN_LIST} {LAYER} {IMAGE_GROUP}-se-nw}
   {NEW:TUPLE_SW_NE_L {BRIDGE_SW_NE} {BRIDGE_SW_NE} {N_TERRAIN_LIST} {S_TERRAIN_LIST} {LAYER} {IMAGE_GROUP}-sw-ne}
   {NEW:TUPLE_S_N_L   {BRIDGE_S_N}   {BRIDGE_S_N}   *                *                {LAYER} {IMAGE_GROUP}-s-n}
#enddef

#define NEW:BRIDGE_NORTH_L BRIDGE_SE_NW BRIDGE_SW_NE BRIDGE_S_N END_TERRAIN_LIST N_TERRAIN_LIST S_TERRAIN_LIST LAYER IMAGE_GROUP
   {NEW:TUPLE_SE_NW_L {END_TERRAIN_LIST} {BRIDGE_SE_NW} {N_TERRAIN_LIST} {S_TERRAIN_LIST} {LAYER} {IMAGE_GROUP}-nw}
   {NEW:TUPLE_SW_NE_L {END_TERRAIN_LIST} {BRIDGE_SW_NE} {N_TERRAIN_LIST} {S_TERRAIN_LIST} {LAYER} {IMAGE_GROUP}-ne}
   {NEW:TUPLE_S_N_L   {END_TERRAIN_LIST} {BRIDGE_S_N}   *                *                {LAYER} {IMAGE_GROUP}-n}
#enddef

#define NEW:BRIDGE_SOUTH_L BRIDGE_SE_NW BRIDGE_SW_NE BRIDGE_S_N END_TERRAIN_LIST N_TERRAIN_LIST S_TERRAIN_LIST LAYER IMAGE_GROUP
   {NEW:TUPLE_SE_NW_L {BRIDGE_SE_NW} {END_TERRAIN_LIST} {N_TERRAIN_LIST} {S_TERRAIN_LIST} {LAYER} {IMAGE_GROUP}-se}
   {NEW:TUPLE_SW_NE_L {BRIDGE_SW_NE} {END_TERRAIN_LIST} {N_TERRAIN_LIST} {S_TERRAIN_LIST} {LAYER} {IMAGE_GROUP}-sw}
   {NEW:TUPLE_S_N_L   {BRIDGE_S_N}   {END_TERRAIN_LIST} *                *                {LAYER} {IMAGE_GROUP}-s}
#enddef

{NEW:BRIDGE_MAIN_L  *^Bhx\ *^Bhx/ *^Bhx|                                                * * -80 hanging}
{NEW:BRIDGE_NORTH_L *^Bhx\ *^Bhx/ *^Bhx| (!,*^Bhx\,*^Bhx/,*^Bhx|,C*,K*,W*,S*)           * * -80 hanging}
{NEW:BRIDGE_NORTH_L *^Bhx\ *^Bhx/ *^Bhx| (!,*^Bhx\,*^Bhx/,*^Bhx|,!,C*,K*)               * * -80 hanging-short}
{NEW:BRIDGE_NORTH_L *^Bhx\ *^Bhx/ *^Bhx| (!,*^Bhx\,*^Bhx/,*^Bhx|,!,W*,S*)               * * -80 hanging-water}
{NEW:BRIDGE_SOUTH_L *^Bhx\ *^Bhx/ *^Bhx| (!,*^Bhx\,*^Bhx/,*^Bhx|,C*,K*,W*,S*)           * * -80 hanging}
{NEW:BRIDGE_SOUTH_L *^Bhx\ *^Bhx/ *^Bhx| (!,*^Bhx\,*^Bhx/,*^Bhx|,!,C*,K*)               * * -80 hanging-short}
{NEW:BRIDGE_SOUTH_L *^Bhx\ *^Bhx/ *^Bhx| (!,*^Bhx\,*^Bhx/,*^Bhx|,!,W*,S*)               * * -80 hanging-water}

The code is neither huge nor complicated, and it actually already has not only special cases for endings near castles (like the current stone bridge) but also for endings in water. I would actually like to convert the mainline stone bridge back to that cutting. It is a prerequisite to clean up the bridge-castle transitions, and finally it would also allow me to finish and commit the underground stone bridge.

Thanks

Lurker

[zookeeper]

Looks good. Maybe I'm missing something, but the WML seems rather overly complicated.