How to get flow map without re-Eroding terrain

Bug Reports
#1

Hello, is there a way I can export out a flowmap without having to use the erosion device again on my terrain?

I have created my heightmap in world machine, brought it into the game engine, made some changes to the height with the game editor tools, and now I need to bring it back into world machine to redo the colormap to bring into photoshop and I need the masks from the flow/wear/deposition map from the Erosion device without having to re-Erode my map.

Any help would be appreciated.

Thanks,
ManaElement

#2

If all you’re doing is changing the height in the game engine, and you already outputted the flow/wear/deposition maps, you can still use those maps as they should work in a Y projection. If you didn’t already output them, then you’ll have to erode it again and output the maps.

#3

Got your point.

Well, the fact is that erosion flows output is closely related to the terrain heights and shapes and it’s not just a matter of marking the “channels”.
When you erode, WM calculates movement of debris and sedimentation of the same debris, and then marks the lines through which the debris moved: thus you cant calculate erosion channels without some terrain actually moving top-to-bottom over a mountain/hill.

So no, you cant calculate flowmaps without an actual erosion effect.

Anyway, if all you did was re-scaling altitudes or just lowering some peaks, you should still be ok with the original erosion flowmap.

#4

Thanks guys.

JimB - I already did output the flow maps before I brought the heightmap into the game engine. I can reuse them, but they wont be accurate as I have change the terrain in some places in the game engine.

Zehryo - This makes sense about how the flow map is created. I did a little more than just lower/raise the terrain in the game engine. Some areas were flattened out and a road tool was used to create paths. So some areas that had the flow map may have a road or an area flattened out right through it and that doesnt look accurate in the colormap. I can tweak the flow mask in photoshop, its just going to be a pain in the butt and take me a lot of time.

Thanks again.

#5

Ok, try this.

  • Export your terrain heightmap from the game editor and import it back in WM through a file input device (watch for height scales).
  • Set an erosion device right after the file input one.
  • Configure the erosion decive to a standard, non-filtered, non-geological type, with an average rock hardness and sediment carry amount (everything else to default)
  • Then play with the sediment amount until you get the right look of the flowmap

Here a trick to keep an eye on the final result: connect an overlay view output device to the file input device and to the erosion flowmap channel (file input device -> [overlay primary input] ;; erosion flowmap -> [overlay secondary input]).
This way you’ll have a glimpse of the flowmap over the non-eroded terrain; the non-filtered erosion should change the overall terrain look not too much so that the flowmap actually fits the original terrain shapes (check attached screenshots).

The point of this all is to use YOUR edited heightmap with WM’s erosion flowmap, which should blend in pretty well, if you dont use strong erosion effects.

It’s a silly idea, but it’s all I could come up with, at the moment.

NOTE: I’ve attached three pics showing the devices workflow, the erosion device configuration I’ve used to test and the 3D view resulting from this setup (default perlin terrain + terrace from WM startup chain).

#6

Thanks again Zehryo!

I gave it a try. For the most part this worked and I think its about as close I am going to get for getting a new flow map from my existing heightmap. I can just output the new flow mask from this setup for my color map and it fits pretty close to my modified heightmap.

I really liked the use of the overlay view to see the flow map easily, that was a good tip I havent thought of yet.

Thanks again for explaining it clearly and for taking the time to do screenshots, very nice of you :smiley:

#7