Thanks for the encouragement. I just tried it again, with the following transformations coded. The ones that worked are flagged.
Revert to base terrain:
*Jungle
*Forest
*Marsh (apparently the Marsh -> Coast that Firaxis put in doesn't function. But Marsh to base terrain does.)
Also coded but not functioning:
Tundra -> Grassland
Grassland -> Plains
Plains -> Desert
Ocean -> Coast
Coast -> Plains
Ocean -> Hills
I didn't have the Hills -> Mountain -> Volcano path active, so we know that wasn't interfering with Desertification.
Incidently, Pfeffersack, what transformations did you have in Alpha Centauri? I imagine some kind of terraforming effect, where you were bringing green to a desolate landscape as you built more and more terraforming improvements. Too bad we can't have nuclear waste give a food bonus; we could use them as oxygenators or seed dispersers.
EDIT: This is off topic, but I've found some other things in my testing:
a. Barbarians won't use nukes. Also, nukes cannot be made to do defensive bombing (when they are in a stack of attacked units).
b. The AI won't use ships that build roads in water.
c. If ships are given the Build Roads job, Harbors don't work. Instead the game waits for sea lanes to connect trade routes.
d. Nukes that are detonated in the water (with no visible polluting effect) still affect global warming.
EDIT2: I tried it again with the following transformations coded.
None of them worked. This was with a red sun (I'm launching 60 nukes on turn 1 to jump-start global warming).
Tundra -> Grassland
Grassland -> Plains
Plains -> Desert
Ocean -> Coast
Coast -> Plains
Ocean -> Hills
So I think that weakens the theory that vegetation transformations are taking priority over regular terrain changes. With no vegetation transformations coded, and hills and volcanoes left out, nothing happened at all!
EDIT3: I removed all water transformations, and all vegetation transformations. The remaining ones are listed below. Again, none worked. (This was with a red sun after firing 60 nukes. I also have 20 cities with a population over 13 in the scenario.)
Tundra -> Grassland
Grassland -> Plains
Plains -> Desert
I have a new hypothesis. So far, the only transformations that have worked, are ones that did not require the base terrain of surrounding tiles to change. My theory is that Grassland -> Hills would work, and so would Hills -> Volcano, and Grassland -> Volcano. I also hypothesize that Grassland -> Marsh, Forest, or Jungle would work, and that Plains -> Forest and Tundra -> Forest would work. See the pattern? None of these require a neighboring tile to change its base terrain when the transformation occurs. Whereas others I have tried (that failed), such as Grassland -> Plains, do require that surrounding tiles shift to accomodate the change. I think that this is the underlying problem. If this is true, then I should also be able to do the following transformations: Marsh -> Hills, Marsh -> Volcano, Jungle -> Hills, and Jungle -> Volcano. This is because the underlying terrain for Marsh and Jungle seems to invariably be Grassland.
EDIT4: Success! The following terrain transformations were coded in my last game, and all worked:
*Grassland -> Marsh
*Plains -> Forest
*Hills -> Jungle
*Marsh -> Hills
*Jungle -> Volcano
*Volcano -> Grassland
*Tundra -> Forest
*Mountain -> Marsh
What does this mean? It confirms my hypothesis that terrain transformations are only supported if they do not affect the
surrounding base terrain. So, Tundra, Plains, and Desert could not change to anything else, although Tundra and Plains could have Forest laid over them. Also, the following list shows six tiles that are interchangeable: you can code them in any order of transformations, even if they loop in a circular progression (!):
Grassland
Marsh
Jungle
Hills
Mountain
Volcano
This is due to the fact that all six of these tiles share the same base color at the edges (deep green aka grassland), so surrounding base tiles are not affected by the transformations. Note that if Forest is coded to transform to something (other than base terrain), it probably won't work. This is hypothesized because Forest can occur on 3 different types of base terrain, some of which aren't interchangeable with the above mentioned Grassland family.
Which brings us back to some hearsay.
Pfeffersack said:
One of the vanilla civ patches changes global warming to target vegetation squares(forest and jungle) first before changing "real" terrain.So you can reforest tiles to absorb GW.
If what Pfeffersack said is true, this patch to which he refers may be the culprit--it may have forbidden transformations that affect the base terrain of surrounding tiles.
Does this mean that global warming doesn't work? Absolutely not! Although I'm disappointed that I can't make the seas boil and dry up into deserts and mountains, it does suggest a new mod. While global warming cannot cause the climate to get hotter and
dryer, it can be used to make the climate hotter and
wetter. I suggest that the following terrain transformations would make a logical and unified progression for global warming:
Tundra -> Forest
Plains -> Forest
Grassland -> Marsh
Marsh -> Jungle
Volcano -> Mountain
Mountain -> Hills
Hills -> Grassland
The last 3 on the list would represent erosion--mountains being worn down by torrential rains caused by severe climate change. If you want to make the whole progression cyclical, you can make new volcanoes erupt out of the jungle. That would yield the following progression:
Grassland -> Marsh -> Jungle -> Volcano -> Mountain -> Hills -> Grassland, etc.
Unfortunately, Plains and Tundra would be stuck with Forest, and Desert and Floodplain would not change.
I've incorporated this research into a new mod, called nucleartropics.
For maximum tropification, go here!