Inverse earth in Fractal Terrains 3?

MadMattUK

Hi. I'm very new to Fractal Terrains 3, so my apologies if this question is obvious or answered before.

What I'd like to do is take the Earth map and invert it so that the deepest ocean becomes the highest land and vice versa.

I had an idea that the Maths tools would be the way to do this but I can't get it to achieve the effect I want.

Can anybody help me with how to achieve this?

Many thanks.

Mateus090985

As long as I know you cannot do it, BUT I am not an expert on FT3 and have only worked very lithly on it.

jslayton

Your best bet is to use an external tool such as Wilbur to invert the data. A version of Wilbur ships with FT and a current one can be located at http://www.ridgenet.net/~jslayton/software.html if you'd like to try it.

The process in Wilbur is:
1) Load the terrain data that you want to invert. You'll probably want to set the edges of the map to top-90, left=-180, right=180, and bottom=-90 using Surface>>Map Info
2) Use Filter>>Mathematical>>Invert to flip the heights around zero. There are many other ways to achieve this result in Wilbur, but this one is the most direct.
3) FT and Wilbur disagree on which way is up, but they share the MDR file format. Use Surface>>Rotate>>Flip Vertically in Wilbur to let Wilbur and FT communicate more effectively.
4) Use File>>Save As to save the terrain as an MDR surface. FT can read this file.

Importing the file into FT involves using File>>New:Binary File and follow the prompts.

Trying to do this processing directly in FT is probably possible, but it would involve processing using Tools>>Actions>>Burn Into Surface followed by uses of the Tools>>Global Math Tool to move the offset data to the prescale offset channel, followed by setting the global roughness channel to a negative value that will adjust the data to the correct range. It's much simpler to use the external tools if possible.

On the other hand, if you just want to invert the altitudes in a world defined in FT, it's just a matter of setting the global roughness channel to -1 (or use the global math tool to evaluate "roughness = roughness multiply constant -1" if you want to preserve any roughness changes).