ProFantasy Community Forum

Prescale Offest Not Working

Lord_SalamanderLord_Salamander
in Mapping with ProFantasy's Software
Hey guys, I'm having a trouble using the prescale offset tools. I imported the etopo1 binary data file and got it working, but when I attempt to use the prescale offset tools (with the check box enabled), they don't seem to work. Anyone have any suggestions? They tools work just fine when I create a new fractal map.
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Comments

  • MonsenMonsen Administrator 🖼️ 81 images Cartographer
    I believe the prescale offset tools work by modifying the data output by the fractal function that generates the map. However, a binary file such as the etopo1 data set is not based in a fractal function, and the altitude is not based on the data the prescale offset tools modify, so they will not work with this type of map.
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  • RalfRalf Administrator, ProFantasy 🖼️ 18 images Mapmaker
    Yeah, you will need to use "Burn Into Surface" to make the data internal to FT3 before you can apply changes to it. Make sure to set the Editing Resolution as high as possible before you do that, to minimize the loss of data.
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  • Lord_SalamanderLord_Salamander
    After Burn into Surface it still doesn't seem to work. Is there something I might be missing?
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  • jslaytonjslayton Moderator, ProFantasy Mapmaker
    edited May 2013
    Prescale Offset won't do what you're expecting here (at least not if you're used to how it works with the fractal-based worlds). When you use Burn Into Surface, the entire basis function (fractal function or input file data) is moved into the offset channel and the roughness channel is set to 0. If you're trying to adjust Earth data and keep continental shelves, I'm afraid you're pretty much out of luck.
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  • Lord_SalamanderLord_Salamander
    Hmmm, that's unfortunate. It always seemed prescale offset made the changes look somewhat more natural looking.
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  • jslaytonjslayton Moderator, ProFantasy Mapmaker
    Prescale offset happens before the exponential operator on the fractal function that's responsible for the continental shelves, so the prescale edits participate in the continental shelf activity. WIth an external data source, there isn't a fractal function and so the prescale offset has no more effect than the regular offset. The same thing is true after Burn Into Surface: the fractal function is effectively turned off by setting the roughness channel to 0.

    I don't know a way to get the same sort of effect with binary input data, because the continental shelves and other effects are already in the data and can't be just hacked together the way that the continental shelves on the fractal things are. FT's fractal altitude computation is altitude=((prescale + fractal) * roughness + offset), while its altitude computation when using a binary input file is altitude=input_file. After Burn Into Surface is used, the roughness channel is set to 0, meaning that the computation is altitude=offset because the (prescale + fractal) term is reduced to 0.
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