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RTG is changing a lot of terrains between 1.10.2 and 1.11.2. The Ocean/Deep Ocean change can be seen underwater as chunks load as you're going from lower to higher, which is 1.10.2 to 1.11.2 Ocean and 1.11.2 to 1.10.2 Deep Ocean. It's not a big deal though - it's still through the water effect, it's at the limit of your loading, and it disappears as soon as the next chunks load. You can easily miss it if you're not looking for it.

So something I noticed with the CC + Mountain Chain / RTG combo. Rivers. They have an annoying tendency to stop.

Older versions of 1.7.10 would have rivers carve out passes through the mountains. While realistic enough, it got enough "ugly" comments to be removed. Fine.

But I noticed that extreme hills in RTG, even with mountain chains, are not always high up. There's plenty of low ground in there as well. And, I've had rivers basically come up along the base of a mountain, and then stop. A small 5 block detour, and the river could continue around the base of the mountain.

So why not? I don't know how early in the generation the "desired path" of the river is determined, nor the exact ordering of "Here's the actual ground height" / "whoops, too high, lets chop the river now", but is there a way to say "Hey, this is sufficiently close to the base of the hill, lets look around for flat land and move the river over there"? (And given the whole nature of one chunk's generation triggering another chunk's, I know that there's a difference between being able to describe it, and being able to implement it).

(Yes, I know it would be for 1.10+ at this point. Still sounds like an improvement).

The current algorithm places the rivers and then fits the terrain to the rivers. Any kind of moving the rivers would require a completely different algorithm, and any way I can think of would require an additional stage of terrain manipulations. (Also, it's one of those things that seems very easy but actually doing it algorithmically is hard). We could change the details of what about the terrain makes the algorithm give up and just not put the river there, but that wouldn't change the occasional problem of a "too small" interruption of a river, just change when and where it happens.

The most likely "fix" for the brief interruption problem would be to figure out a way to make river canyons look good, which I think is comparatively doable. It would still be surprisingly hard to figure out what's a 'too brief' interruption and we'd probably end up putting rivers back through all the mountainous terrain, which would have both good and bad parts.

We've tried doing flowing water and it's problematic with the rules of Minecraft. It's hard to keep it from "escaping" and making a mess. Some combination with Streams is possible but I wouldn't want to lift part of the mod for RTG.

I don't stress out too much about any odd imperfections like terminating streams as long as they're rare. You just can't stop that with a localized random generation system. That's part of the reason I'm not too stressed out about the problem of excessively short river interruptions - it happens, but it's also fairly uncommon.

More or less, yes, the rivers are generated before the height map. The generation of the height map is complicated. For each biome it generates the height at each block. Then that height is adjusted for the river value, which is generated independently, for biomes that have rivers. Then all the biome heights get weighted together with a complicated formula based on the biomes present in the neighborhood. That final value is what you'd normally consider the "height map". We could make a pre-river height map by weighting together the pre-river by biome maps, but we don't at present. It used to be done that way but not anymore and for a few biomes like Bayou we use the river-weighting step to do some biome-specific things and we'd have to give that up to revert it.

I don't mind the occasional terminating stream -- heck, it's reasonable that not all rivers cross all mountains (see the Continental Divide in the USA), but it's more like I have yet to find a river that crosses any mountain zone in 1.7.10 when RTG plus CC/mountain chains is active.

Quote from Keybounce»

I don't mind the occasional terminating stream -- heck, it's reasonable that not all rivers cross all mountains (see the Continental Divide in the USA), but it's more like I have yet to find a river that crosses any mountain zone in 1.7.10 when RTG plus CC/mountain chains is active.

That's actually intentional - the mountain zones break the rivers into basins so most of the time you'll get rivers flowing logically from a mountain source to some at least half-plausible destination like a swamp or lake. It also makes the brief terminations less common. That said, besides the fact that it's a good approximation for maps, it would be hard to make rivers *sometimes* cross mountains. Always is easy (even if it often would look ugly), never is easy, but sometimes is hard.

With respect to how expensive it would be in CPU time, (and in the time it would take to code it and work out all of the bugs,) to make rivers look nice in mountainous biomes.. it's almost not worth even thinking about it, let alone trying to implement it.

And, Keybounce, you're talking about 1.7.10.. that version is dead. Even if, in the future, we manage to improve rivers in mountainous biomes it's not something that will ever get backported that far.

The reason why rivers stop occasionally (are disabled) in mountainous biomes is because most of the time it ends up looking like **** if they were to continue. This is clearly unrealistic and ugly:

But in some cases there are nice results..

Oh, I am fully aware that 1.7 is dead. I am thinking of 1.10 or 1.11 at this point -- that being able to (Eventually) upgrade to a future version of minecraft that will generate really good looking terrain.

just a quick question will RTG allow Floricraft FlowerLand Biome? I found it easily in vanilla but haven't found it on RTG ( note I haven't had time to test fully though )

Try using the same seed and going to the same location.