Deeper zones? Well, why not?

[boformer 3,169]

Today I inspected the zoning code of the game. It seems like the original plan of the developers were 8 cell deep zones. All of the data structures were made for that.

That means it might be possible to increase the maximum growable size to 8x8!

I'm currently trying to decrypt the decompiled code (which misses hints, comments and variable names). So far everything looks good, I understand what it does and which passages have to be changed.

Here is a screenshot of a test: In the debug window you can see the output of a test script. It displays the "valid mask" of the zone block you see. A zone block has a max width of 8 cells and a max depth of 8 cells (though only 4 are being used). When you draw a pedestrian path on a cell, it is marked as "invalid" (0) as well as all cells behind it (that's why there are 5 zeros in a row).

[SimCoug 5,973]

Interesting... if they really did build the game anticipating lots as deep as 8 cells, I'm curious why it hasn't been made available as an option or something yet.  Seems like that is near the top of the list of 'fixes' that the community has been asking for.  Nice find!

[Ocram's Razr 964]

I remember reading about oddities with narrow-deep (1x8 tile) lots and curved roads. My solution is for narrow-deep buildings with front plazas or parking, so that tiny 1x1 buildings don't grow in 8-tile deep lots.

[boformer 3,169]

33 minutes ago, OcramsRzr said:

I remember reading about oddities with narrow-deep (1x8 tile) lots and curved roads. My solution is for narrow-deep buildings with front plazas or parking, so that tiny 1x1 buildings don't grow in 8-tile deep lots.

That's exactly the problem. A 1x1 building would grow on a 1x8 zone block, leaving 7 cells of unused space. Even with parking lots and decoration, this looks really strange.

These narrow-deep lots will often appear on curved road segments.

3 solutions for the problem:

1. Limit zone depth to 4 cells on curved roads (quite simple, and "solves" the problems)
2. Tune the zone block spawning algorithm so it spawns wider blocks (complex, does not fix the problem in all situations)
3. Implement a more intelligent spawning algorithm (complex, but this has to be done to support 8x8 lots. The question is how intelligent it will be)

Probably we will end up with a combination of these solutions.

[Shroomblaze 320]

Amazing find. I really hope you figure this thing out!

[Mr_Maison 2,426]

 I hope this works. Looking real good so far. I agree with others...great find!

EDITED to delete unnecessary chatter.....

[Ocram's Razr 964]

Japan has pencil towers of multiple depths and if 1x8 tile zones show up mainly on curved roads, wedge-shaped buildings could potentially fill up 1x6 tile zones (2 tiles of entrance plaza would look fine).

I'm surprised not to have seen 1x3 or 1x4 midrise or highrise buildings on the workshop yet. Maybe I haven't looked hard enough, yet.

[boformer 3,169]

2228 lines of code. That's the commented and decrypted ZoneBlock source code.

The decompiled source is only 1360 lines long, I added a lot of documentation and line breaks for readability.

Some of this was some quite complex geometry and bitmask code...

Results so far:

• The data structure which stores the zone type of each cell is too small (an extra data structure would be needed for deeper zones)
• Especially the monster method that spawns new buildings on empty zones would need heavy refactors to support larger zones
• The existing spawning algorithm tries to avoid 1-cell wide gaps between buildings
• Basically every single method of this class (actually struct) must be replaced to support larger zones because the zone depth constant is baked into them

So far it looks like a slider to set the zone depth when placing the road is possible.

The next thing I will look at is the ZoneManager class. It looks like it requires less modifications (750 lines of decompiled code).

The zones are rendered by a class named TerrainPatch. There is one of these patches for every map tile, and each contains a dynamic 512x512 texture that contains the zone information (colors depend on the angle, that's why it looks so strange)

Understanding the rendering code will be a challenge. The same class also contains render textures for clipped, pavement, gravel and field ground textures (yes, a brush for that is possible).

[Shroomblaze 320]

43 minutes ago, boformer said:

The same class also contains render textures for clipped, pavement, gravel and field ground textures (yes, a brush for that is possible).

OMG Yes, we need a brush for those textures, I'm tired of seeing people us parks.

[Ocram's Razr 964]

If different roads could support different depths, I suggest only giving 3+ (2/1 or 3 one way) roads the option of 8-deep zones.

[boformer 3,169]

ZoneManager is now also inspected and just one or two changes are required to support larger zones.

I also looked at the rendering code. No changes are needed, it should just work.

Next step is ZoneTool, which will require some changes.

[boformer 3,169]

ZoneTool is now also inspected (though I didn't decrypt every single line of code).

Here are the overall results:

• ZoneBlock requires 36 changes (almost every single method) and major rewrites of the spawning algorithm
• ZoneManager requires changes in 2 methods
• ZoneTool requires changes in 5 methods
• RoadAI.CreateZoneBlocks must be tweaked (low-priority)
• A custom data structure is needed to save the zone type data of the extra cells

I also did a test with the zone brush fill tool: It always attempts to fill a 64x64 area, and it doesn't matter how deep the zones are. No problems here!

The picture also gives you an idea how 8 cell deep zones will look like. Just imagine half of the roads would be gone

[Shroomblaze 320]

Looking Fantastic!!! I will have to make a large growable building for this when its working.

[ghosty20 150]

Should be interesting to see how well it all works, though importantly how much of a hit on the system it might cause.. But will be interesting all the same..

[boldlybuilding 873]

You know, if you or someone else can do this, make a larger growables mod, that would inspire me to make more Simcity 3K buildings in the future!

Many small lots and houses in Simcity 3000 Unlimited amount to a 2x2 area in CSL, and many larger moderate buildings amount to 4x4 in CSL, but most of the major iconic growables and towers have a 6x6 footprint in CSL, with the largest growables - a few large skyscrapers - being 8x8 in CSL. (I figure 1 tile in SC3K equals 2 tiles in CSL, and that scaling seems to work.) So if you can get us 8x8, you know what that would mean?

CITIES: SKYLINES 3000!

[DaHindi 11]

That could be the beginning of a realistic looking industry

 

[boformer 3,169]

In theory 16x8 or 8x16 growables would also be possible. Even 16x16 though that would probably be overkill.

Right now I'm looking at different parts of Baltimore (just a random find on Google earth).

• Many of the larger high-rises I would consider as growables are about 80x60m (10x8 or 12x8)
• Small warehouses and factories are 64x64m, going up to 200x100m (that's definitely not possible).
• Larger commercial with some parking spaces start at about 64x64m going up to 150x150m (and larger)
• High-wealth low-density lots easily exceed the size of 64x64 (though that would be an acceptable size)

I think the current maximum plot sizes (16x8, 15x9, 14x10, 13x12, ...) would be a good goal.

All that would require a quite complex spawning algorithm, because the "gap avoidance" of the current algorithm must be scaled up for larger lots (you would not want a 2x8 gap between two 12x8 factories).

I think a slider to adjust the size of the buildings would also be required when there is such a huge size range. I feel that only relying on styles or themes would not work.

Another thought is that roads with deeper zones must be more expensive. Otherwise it would probably misbalance the game.

[boldlybuilding 873]

This is getting me excited. Finally, the possible possibility of bigger zones and more realistically-scaled buildings. You know how much I hate the idea of scaling things down.

[GC_Vos 714]

Woah this is breakthrough stuff! Great work!

[boformer 3,169]

We are getting closer:

 

Next step would be the data structure that stores the zone type of the extra cells. Right now it is not possible to zone them:

There are also a few collision bugs:

[boformer 3,169]

Just now, AJ3D said:

Are there any performance downsides to having the ZoneBlocks be 16+ tiles deep?

It does some additional calculations (iterating through 8 instead of 4 cells), but that's not taxing on the CPU.

[SimCoug 5,973]

One of the biggest hang ups for me was the limited growable zone size, so this is really encouraging!  Awesome work!  I'm still wondering why an entire team at Colossal Order couldn't make this happen by now... 

[BLANKBLANK 4,414]

And now one of C:S biggest flaws is being addressed. Well done boformer!

[boformer 3,169]

27 minutes ago, SimCoug said:

One of the biggest hang ups for me was the limited growable zone size, so this is really encouraging!  Awesome work!  I'm still wondering why an entire team at Colossal Order couldn't make this happen by now... 

Who knows, maybe there is some kind of critical bottleneck that will stop me...

Also, little update: I just solved that collision issue. It was my own fault.

[Ocram's Razr 964]

Apparently there's a way to make certain buildings connect (using skybridge, lobby, or similar props) when they are next to each other though I would indeed enjoy seeing 8x8 skyscraper lots (buildings could be 6x7).

[SimCoug 5,973]

11 minutes ago, boformer said:

Who knows, maybe there is some kind of critical bottleneck that will stop me...

Also, little update: I just solved that collision issue. It was my own fault.

I, for one, hope that is not the case 

[boformer 3,169]

I guess this counts as a milestone:

Right now the extra data for the deeper cells is not saved in the savegame, but that's a rather simple task compared to the rest.

[Shroomblaze 320]

This is Beautiful!

[boformer 3,169]

Here is the current source code.

I will finish the serialization and configurable zone depth, then I will take a break from Skylines modding for a while. Other developers can take the source code and do whatever they want.

To make the mod usable, a few things have to be done:

• Rewrite the growable spawning algorithm to support larger lots (there are a few hints in the code, but this is a major task)
• Make compatible with other mods (or warn players that incompatible mods were found)
• Re-use the "Larger Footprints" code to increase the growable size limit
• Add a way to influence lot size in a district
• Add some kind of ghost mode

Right now the mod is incompatible with Building Themes, 81 Tiles, Building Simulation Overhaul and probably a few other mods.

[boldlybuilding 873]

That does sound like an awfully big task. Do you think other modders would be up to it in your absence? It'd be great to start making larger growables eventually.