Purno's New Bridge Graphics

SHADOW-XIII · **Posted:** Tue May 04, 2004 10:10 am

very nice .. I cannot wait to .. keep making them .. maybe some of us could provide some stats of those bridges, like year its build, max speed, min and max length, etc

Purno · **Posted:** Tue May 04, 2004 10:18 am

SHADOW-XIII wrote:

very nice .. I cannot wait to .. keep making them .. maybe some of us could provide some stats of those bridges, like year its build, max speed, min and max length, etc

Very good idea. But I've already made some suggestions about bridge min and max lenght, it's in the .png files (included in the .zip file).

Petaja · **Posted:** Tue May 04, 2004 12:57 pm

Absolutely great!

Now I'm wondering how will I get those to my game too??

Purno · **Posted:** Tue May 04, 2004 12:58 pm

Broodje is trying to add some bridges in a grf file.

Petaja · **Posted:** Tue May 04, 2004 1:07 pm

OK, lets keep waiting. It's really worth of it this time

Purno · **Posted:** Tue May 04, 2004 1:08 pm

Broodje is gone for some hours now. So I think it will be tomorrow when there will be some progress.

Szappy · **Posted:** Tue May 04, 2004 1:17 pm

Hello everyone!
A few posts back I made a promise of writing a guide to the bridge graphics. Well here it is.
Mind you, this is an 0.01 version

so any comments are welcome...

I attached an image which is a part of the trg1r.grf file, the original graphics, to make this explanation easier to understand. The numbers in () are examples (not exclusively) from the image.

Part I - generic bridge sprites

First of all, all the bridge types use the same on- and off-ramps (sprites 2437-2452, the maglev and monorail ones are stored elsewhere) EXCEPT the wooden bridge has one of it's own (2529-2554). The program recolors the edges according to the bridge colour.

The second most important thing is, that each bridge square contains two sprites. The reason for this is that a vehicle passing on the bridge will obscure the back sprite (ex. 2453), while get obscured by the front sprite (2455). The main problem with this, is that while the back sprite contains the running surface (ie. road/rail/mono/maglev) the front sprite is the same for all of them. So if you change the appearance of the front sprite all the bridges of that type will look like it. Although if you change the back sprite, only that type (ie. road/rail/etc) will change.

-edit- So if a roadset contains altered bridges for the roads, it must also contain altered bridges for rail/mono/maglev otherwise the graphics will look bad.

Third. The bridge sprites are recyled: all the suspension bridges (2453-2492), or all the cantilever (2507-2528) bridges use the same sprites, ttd just recolors them to yellow/gray/red/etc. I'm not sure yet, but I think it is their color that tells ttd what to change.

Fourth. The bridges have supports (2477-2484 for the suspension, also 2491-2492) which must be drawn properly if you want your brigde to be compatible with the higerbridges supports. I mean, if you drew the supports into the bridge sprites itself, then the bridges will always look 1 level high, thus ugly if built higher.

Part II - bridges in detail

Here I will go into detail on how the bridges are drawn from the sprites.
In part I stated that a bridge block consists of two sprites. From now on I'll use "blocks", meaning on square length of bridge.

1) Wooden bridges
are fairly easily built, because it only has one block (2545-2552), which is placed one after another, and it even has its own on/of ramp (2529-2544).

2) Steel girder bridges (2499 type and 2553 type)
also has one intermediate block, but uses the generic on/off ramp as all bridges from now on. (I think those blue holes in 2553-2556 are not needed, because 2557-2558 will obscure them, but I have never tested this assumption, so feel free to comment)

3) Concrete bridge
has one internal block too, but a VERY important issue is, that this block is used by the suspension bridge too, so it must fit with it (will explain later).

4) Cantilever steel, and tubular bridge
has three different internal blocks, on start/end on both endings (2507,2509), and an inermediate one (2508). The intermediate ones for the tubular look like ordinary tracks (2570-2573), but must not be confused with them... The cantilever bridges need the changeabe color, because there are 3 types of them, so this must be differentiated.

5) Suspension bridges
are the most complicated ones. They start/end with a special block (2453-2454) but then are dependant on the full length of the bridge (without ramps, just add 2 to get the full dragged length):
2: start(2453)-end(2454)
3: 2453-2487-2454 use of a one-block long connection between two pillars (2487)
4: 2453-2458-2457-2454
5: 2453-2458-2496-2457-2454 notice here the usage of the concrete bridge sprite (2496) which fits with the rest of the bridge, and also gets recolored
6: 2453-2458-2457-2458-2457-2454
from now on there is just an alternation in the bridge middle (2487 --> 2458+2457 --> 2458+2496+2457) while the ends are getting suspension blocks (2457+2458)

If you didn't understand all this, then go on and build bridges with increasing lengths, and you will...
I hope this helps in making new bridge graphics, and understanding the workings...

Szappy

broodje · **Posted:** Tue May 04, 2004 4:29 pm

hmm yes indeed I was gone for some time (planing a vacation...) I will look at the bridges again, as you already saw the suspension bridge purno made is a bit not posible I'm afraid, but we have diskussed what bridges will be there, just wait and see

lobster · **Posted:** Wed May 05, 2004 10:49 am

but wait: if i'm correct, one can only overwrite the existing bridges instead of adding the new ones to the old, except when working with OpenTTD, right?

Szappy · **Posted:** Wed May 05, 2004 12:05 pm

Here are some conclusions from the guide above:
-the on/off ramps are specific to the running surface, and does not interfere with anything, so road/rail/mon/maglev can have very different styles, except they have to fit with all bridges

-different appearances can be used for ramps starting on level land and ones that start on a slope (idea: concrete/steel). Does not necessarily need the 'magic' color (the one that changes color by bridge type), if a good appearance is found.

-because bridges have the running surface built into them, any bridge set needs to be drawn in the andexx-roadset, and the european roadset style too (maybe using parameter 1 for andrexx, 2 for euroroads)

-any redrawn bridge needs all vehicle types to be made too (I mean rv/trn/mn/mglv), because of the front sprite.
BUT there is an exception to this rule: if a bridge was designed not to overlap with the vehicle running on it (ex. the bridge no5), then the backsprite should contain all graphics, while the frontsprite will be empty.
This way that certain bridge could be totally different for road/rail/mono/maglev, just neither of them should have any parts that obscure the vehicle on it. Idea: bridge no13, 7, and 5 could 'share' the same bridge for different vehicles

-the steel girder bridges only need to fit with the generic ramps, otherwise fully redesignable, but only have one bridge block. These ones could be used for the idea above, except that 7 and 5 has different ending segments, which unfortunately should be excluded

-wooden bridges can be redrawn fully, with ramps, without interfering anything, then you could change the speedlimits with ttdalter. bridge no.9 or 1 would fit here well

-the 3 segment bridges are:steel cantilever and the tubular, the tubular one is only one bridge, so could be redesigned fully, with any appearance. It could use the different look per vehicle type too, but then there should be no 'top' covering it. Unfortunately the cantilever ones are 3 bridges in one set, so any change should use the magic color, otherwise they are not distingushable.

-the suspension bridge is the hardest to alter, because it should look good in any length, which is a hard task. Fortunately no.15 is very close to being made into a complete suspension bridge set. However it needs the following: guide segments repainted into the 'magic' color to be able to change appearance, needs a straight 'unsuspended' piece too, which also looks good on its own as the concrete bridge, not only the very top of it needs a connection between the two ramps, but the side segments too, in case the midlle part is not generated, and also some different ending segment (this is not very important, the normal ones can also be used/can be made later on)

-the concrete bridge should be left alone until the suspension bridge is finished, because of the sharing, but then it needs to align with it, and also needs the special color

-at the moment I don't know how we could do proper bridge supports for these

Dinges · **Posted:** Wed May 05, 2004 1:56 pm

I wish we could change the appearance of bridges :cry:

Szappy · **Posted:** Wed May 05, 2004 2:02 pm

Dinges wrote:

I wish we could change the appearance of bridges :cry:

err... we (/me only giving advices) are working on changing the appearance of the bridges
did you mean changing the bridge generation process?

Dinges · **Posted:** Wed May 05, 2004 2:17 pm

Szappy wrote:

Dinges wrote:

I wish we could change the appearance of bridges :cry:

err... we (/me only giving advices) are working on changing the appearance of the bridges
did you mean changing the bridge generation process?

Yes, that is what I meant, I would have loved it if we could combine sections in an other way, I don't know if it's impossible to do with the patch, but it certainly would be nice :roll:

So, any of the patch crew, is it possible or not :?:

eis_os · **Posted:** Wed May 05, 2004 2:46 pm

If you write it.
As far as I remember TTD has for each Bridge a list of pointers to sprite lists:

start
middlepart1
middlepart2
fillpart1 <- middle part without cables at a suspension bridge
fillpart2 <- Unsure, but thats the part that shows a middle part on suspension bridges with cables.
stop

For Bridges currently not using all pieces, the pointers simple points to the same list as a other pointer. (Sample: Bridgeheads)
The list the pointer is pointing has entries for the back, front, pillar sprite when used...)

In general it's possible to write a system to replace the lists and feed it with new lists that are altered with action 3.
aka newbridges

If there is some volunteer to write such a system he can ask me about more stuff...
(It's the stuff I remember, so some parts can be wrong!)

Dinges · **Posted:** Wed May 05, 2004 7:09 pm

What would such a system involve :?:

I have no knowledge about patching TTD, so that will be a problem I guess :roll:

Petaja · **Posted:** Fri May 07, 2004 9:45 am

Are these bridges impossible to make dowloadable zip-file?

krtaylor · **Posted:** Fri May 07, 2004 5:45 pm

Well, they're impossible to make a zip file that works with the game, anyway. Wait for the Patch to catch up, or GRF encoding to deal with it.

Hyronymus · **Posted:** Fri May 07, 2004 9:30 pm

Or wait for what broodje has to say about it.

lobster · **Posted:** Sun May 09, 2004 11:38 pm

the allmighty broodje, waar zijn we zonder hem.

he's the man with the plan. :wink:

broodje · **Posted:** Mon May 10, 2004 9:32 am

lol,
I feel ashamed to tell you that I was totaly fed up last week with TTD (or at least the NFO part)
I have spoken with purno, and I should have replaced 5 bridges by now, but as you all noticed I didn't do that. I hope I feel more about it this week and more importand I got time to do it.

BTW it should be fairly to do it. Only the sprites has to be replaced, not other things has to be set.

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