Forcing height in Wilbur

[Runninghead]

Hi folks,

I hope this is a fairly straightforward question for someone versed in Wilbur:

What's the best way to stretch your greyscale starting map image across the full range of depth available in Wilbur?

I've an 8Bit image map that goes from white (highest mountain peak) to black (lowest point in the sea) but it seems like it could do with some extra height.

I made the starting image in Photoshop.

Should I be using Surface > Point Process > Explonential, or something else?

[johnvanvliet]

for a 8 bit image
just "normalize " it in ps that stretches it to 0 to 255
but 256 tones is NOT good for a heightmap

normally a 16 bit image is used it has 65536 tones of gray

[waldronate]

Wilbur uses single-precision floating-point values to represent the height data internally, so that would roughly a scaling factor of 10 to the 38th power (with roughly 16 million discrete values over that range). I recommend picking a range of values that you're interested in (say, 0 to 30 000 meters) and then using the Filter>>Mathematical>>Span operation to specify the lowest and highest values in your terrain. If you just want to scale it by a value (say 30 000 / 255), then Filter>>Mathematical>>Scale with a value of 117.65 will do a pretty good job.

If your version of Wilbur has Surface>>Point Process>Exponential available, then you are about 20 versions out of date. I recommend getting a new version from http://www.fracterra.com/software.html if you can.

[Runninghead]

Thanks so much for the help guys.
I learnt a bit about Normalising today and essential Wilbur too intel- it's all good.
I have Wilbur 1.85, running in Wine on Mac ElCapitan but the Wilbur tutorial I've got may be very old (it was called "Doin stuff in Wilbur, I think).
Thank you again for taking the time to reply, I shall try the techniques later today and include whatever gives the best results in my forthcoming tutorial.

[waldronate]

https://cartographersguild.com/showthread.php?t=29412 has general current tutorials. The "Elderly V 1.26" tutorials at fracterra.com are a good 60 versions out of date and are mostly of historical interest. ( In product development circles, "of historical interest" generally means "we're too lazy to clean up that stuff." )