Bridges and Crossings

From AgeofWiki

This tutorial is in three parts. Each section is a step-by-step basic approach to a type of river crossing you can build specifically for Trade Route crossings.

#Simple shallows (ship-passable, foot-impassable)
A #Shallow ford using the Shallow tool (foot-passable, ship-impassable)
#Bridges
#Additional Resources

Table of contents

1 General Tips for Trade Routes

2 Simple shallows

3 Shallow ford

4 Bridges

5 Additional Resources

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General Tips for Trade Routes

When you place a trade route, the local average terrain height is used around the route. Crossing a river with a Route often gives you a raised isthmus of dry land, instead of the nice submerged shallows you are aiming for. You will have to remake your submerged shallows after placing a trade route.

Also, the two or three map squares on either side of a trade route are somewhat inviolate. This means you won't be allowed to place units or buildings in the way of the trade route during a game. Keep that in mind when designing bridges. If you want people to be able to build fortifications along the bridge, make it wide enough that towers, etc. won't obstruct the Trade Route. The same goes if you want people to be able to build docks or towers along the shallows. If the shallows are too narrow and "hug" the Trade Route, buildings won't be permitted and moving large armies across will be a problem. (This can be used to strategic advantage in scenarios where you don't want a lot of naval support.)

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Simple shallows

Start with a river and use Shallows Tool place shallows wherever you intend to create crossings. Make them wide enough to get a sense of how much room your Trade Route will need to cross the river.

If you're not using a Trade Route at this crossing, you're done. Consider using Edit Water to Beautify your river so some sedges and river stones appear over the shallows.

Place a Trade Route on your map and set the waypoints to cross the river at the crossing you just made.

Use the Elevation Picker tool to copy and paste the riverbed elevation. Flatten the entire raised Trade Route crossing to match the riverbed depth.

Use Smooth Tool to draw the river water in over your Trade Route crossing.

Smooth over the edges of the river a bit, but not too much, you want the shallows to be about as wide and as long as the river width.

You can see the trade travois emerging from the river over the shallow crossing. Smooth out the banks a bit more so you can just barely see the trade route track beneath the water.

Now is a good time to test the passability of your shallows. Place a ship over the shallows. If you can place the ship directly over the trade route at all points, the shallows is ideal for naval strategies. If you can't place a ship on the trade route, it is because the water is too shallow. This is better for land-based strategies and means units can walk across the shallows. Learn more about this type below under #Shallow ford.

If you have not already done so, use Edit Water to change water type and Beautify your river. Sedges, river stones, and eddies will appear over your Shallows and along the riverbanks.

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Shallow ford

Review the steps above for making a Trade Route cross a river and submerging the crossing. You should end up with a shallow crossing as seen here.

As described in the first section, test the passability of your shallows. Try placing a ship directly over the trade route or center of your passage. This shallows is ship-passable, but units can't walk on it, the water is too deep.

This shallows is foot-passable and buildable, but ships are not permitted; the water is too shallow.

Hint: A good shortcut to "fixing" your shallows to be passable or not is to create a separate Shallows off to the side using the Shallows tool. Sample the elevation in the Shallows there, then paint that elevation over your Trade Route crossing until you get the desired effect. You may need to smooth the terrain and paint elevations again to get the crossing to be submerged.

You can adjust the width and dimensions of your Shallows further to permit building over the shallows, alongside the trade route. Test with a building or land units.

Finishing touches: Ordinarily you can't build walls or gates over a Trade Route. If this is part of a fixed scenario, you can place the walls and/or gates in the Editor over a Trade Route, and they will function identical to player-built walls and gates as soon as the game starts. To make a gate over a Trade Route, place a long wall segment across the Trade Route.

Select the Wall segment and convert it to a Gate using Objects>Convert to Gate.

Now the gate is in place and will open to let the trade cart through (and your units). But it will keep out enemy units, and can be upgraded just like any normal wall.

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Bridges

This section builds on Custergrant's and ShawDaMan's original Bridges (http://aoe3.heavengames.com/cgi-bin/forums/display.cgi?action=t&fn=12&f=12,,0,10). The idea is the same, but I will spend a little time on it in the context of putting a Trade Route across it.

As above, put a Trade Route over the river. Instead of submerging the entire Trade Route crossing, we are leaving a thin bar of land above the water. For this reason, it's important that this section of the Trade Route be straight.

Smooth out the shoreline along the bar and use the elevation tool to make the bar very crisp, straight, and even. This is the basic Bridge, but it's best to apply some cosmetics so it looks like a real bridge, with paving stones, pontoons, etc.

In ShawDaMan's original example he used sections of ruined stone wall to make a stone bridge. These work very well, and look authentic.

Place the rock walls along the surface of the water. The green bits should be just under the surface; the tops of the walls should be on a level with the top of the sandbar.

Whichever props you use to pave your bridge, go back and tidy up the cliff edges on either side of the crossing. Ideally the bridge crosses the river between piers or built-up quays which you can also make using rock ruins, shoreline rocks, paving terrains, or Inca Wall cliff type.

When you are finished sculpting the geometry of the bridge and its termini, apply a bit of paving uniformly across the bridge. SPC City Streets also work well and give you the option of streetlamps.

You can curve the bridge so it is raised like a bascule span (the bridge bows up to spread stresses over a wider area) and apply props or terrains to the top and sides to mimic a wooden, stone, or natural rock bridge. Unfortunately, at this time it's not possible to make a bridge under which ships can pass.