Underwater Trade Routes 2
From AgeofWiki
This step-by-step guide is meant to walk through creating a Trade Route and then submerging it under a river. It's a supplement to the Guide to Underwater Buildings, Units, and Terrains and to Underwater Trade Routes. This method is recommended for maps which strive for geographic or historical accuracy.
It's possible to place a functional trade route partly or entirely underwater and upgrade it, or route it across a river as part of a bridge or ford (see Bridges and Crossings). This is a very rewarding way to encourage water traffic on your river maps. It adds a new level of strategy to controlling the sea. And it stashes the trade route out of the way of your walled city, so you can expand, or turtle up, without hindrance.
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Making the Trade Route
Use the Terrain Grid as a guide to predict where the Trade Route waypoints will appear - roughly one every 8 small map units in any of 8 cardinal directions. This will determine the course of your River.
Remember when you place your Trade Route, it may loop and intersect with itself. A river can do the same, but can only make turns of 45 degrees or less at one time - so if your Trade Route has a lot of right angles and tight turns, your river may not be able to follow these twists and turns. Or, you may need to create a wider river to encompass the turns and loops entirely from shore to shore.
Place your River using the River Tool. Make sure the width of the River is wide enough to encompass the Trade Route plus a square or two on either side, to hide the Trade Cart or Stagecoach from view. To place a River waypoint, place it directly over the Trade Route or as close as you can.
Create your River and verify that the trade route is entirely contained within the borders of the river banks.
You will notice that the Trade Travois poles stick up out of the water - to hide these, lower the riverbed bottom as described in the next section.
Testing the Trade Route
Place Trade Sockets along the river shoreline, as close to the shore as possible. They should be evenly spaced along the shore. Put a balanced number on each side of the River.
Place a trade post on each socket under Player 1 Make sure you can place a trading post on each socket. If you can't, the socket position needs to be adjusted until a post can be built on it.
Open the Triggers menu and set up some simple triggers to test the trade route. These triggers will allow you to playtest the Trade Route and upgrade it as normal, to see the visual effects it has on the Trade Route. Enable or Set Tech Status Available each Trade Route upgrade tech as shown.
Playtest the scenario as Player 1 to see how much XP each trade socket generates. Upgrade the trade route to see the visual effect on the river. Upgrading to Stagecoach or Locomotive may cause these objects to stick up out of the river water and look odd. To hide them, the riverbed is lowered to the minimum depth of -8.00 map units, the level at which the locomotive steam artifact disappears from view.
Lowering the Riverbed and Cosmetic Effects
As seen with the Travois poles above, parts of the Stagecoach and Locomotive peek up out of the water during transit, ruining the illusion of a hidden trade route. To hide these, lower the riverbed by the minimum amount needed to hide the Locomotive, which has the tallest animation.
To find the terrain height needed for hiding the Trade Route objects: Using the Terrain Height Eyedropper Tool, right-click in the riverbed to sample the terrain height at the bottom of the riverbed. Then left-click over the default land terrain off to one side of the river. Pick a spot far away from the river that is still flat. Make a 3x3 hole using this height.
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Now use the Cliff Tool to get the exact height of this riverbed. Right click with the Cliff Tool inside the depression you just made. This should give you a terrain height of -2.000. This is the default riverbed depth for a flat blank map. (The default dry land height for a flat blank map is 4.00). Using the same cliff tool, now adjust the Height of the cliff tool to -8.000. This is the height at which the Locomotive and Stagecoach (and Travois) animations disappear entirely under the water level. Use the Cliff Tool to place a hole of this new depth over the old sample depth, as shown above.
Now return to the Terrain Height Eyedropper Tool, and right-click to sample the bottom of the new hole to get your new lower depth. Paint this depth along your Trade Route inside the River, being careful to stay away from the shores of the River. Use the Terrain Grid to help you. If you accidentally paint over your river bank, you can restore it later using the Cliff Tool and a clifftype like the one used for the original river banks. Test the scenario again, to make sure the fully upgraded Trade Route is now completely hidden under the water. Leave your -8.000 Basin in place for further adjustments until the desired effect is complete.
Final Touches
Build around your Trade Sockets to create riverfront towns, depots, and boat piers. Here, the Spanish city of Toledo is built around a riverfront trade depot along the Tejo river. (Test after placing buildings to make sure players can still build on the Trade Socket.)
Note that fishing, whaling, and naval combat are all possible directly over a Trade Route.
A trade-route-bearing section of river is flanked by shallows in this screenshot showing a fortified city (with moat) on the mud flats, with a trade socket facing a navigable portion of the wetlands.
A very long trade route travels UP the Guadalquivir River to the hillside city of Bailén, where goods are loaded off barges and brought into the city along a central avenue, with trade post and market...
which then ends at the city gates, and is offloaded again to trade barges traveling west down the Guadiana River. This trade route is ENTIRELY submerged for much of its length along two rivers, only to emerge for a brief stretch in the port town. The customs-house and gates hide where the trade cart disappears under the water again.
Warning: Using Edit Water to change water types will overwrite riverbed terrains and erase Beautify objects, such as flow eddies and river rocks. You can add them back manually but it's tedious to get them all in proper flow orientation.
You may get a different effect if you lay the River first, then create a trade route following the riverbed. See Underwater Trade Routes.
For examples of partially submerged Trade Routes and fords or bridges for overland trade traffic, see Bridges and Crossings.
