Some fractal terrain questions

[Naima]

I will test that soon again as I am in the process to go from wilbur back to FT .... but in meanwhile I have a question for Wilbur ....

I have nicely eroded my terrain and I got some very nice and evident big rivers , kind of amazon rivers ... carved into the land slopes ... but when I command to draw rivers those get completely ignored and insteadI get all sort of river that do not match the landscape ... why that? Is it possible to fix?

Also ...

I did load several texture for exmporting maps in wilbur , so I loaded flow map , I loaded grayscale , slope maps , sea mask etc ... saved all as png ... but the only output is always and only the heightmap ... what I have done wrong? Shoudl I save somehow differently?

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Tough in FT instead seems to work much better and it finds them ....

btw I think the problem loading from Wilbur format to FT was because I kept both programs open at the same time loading a file from the other , perhaps this caused the issues, I noticed that when I switched of one of the two I coul dload fine . but the file from wilbur needed to be not only flipped vertically but also horizontally .

[Thurlor]

You need to fill the basins before drawing the rivers.

Wilbur can save two types of png. One is a height-map the other is a colour image.

[Naima]

thankyou right , I was confused as in the tutorial said save as png but didn't specify that there was a difference between surface and texture .

Retested and anyway the rivers do not work in Wilbur .
But they do in FT ...

As for FT How can I save the River overlay image from FT to PS ? I did impose a whole black background altitude but not sure if thats the direct way to get it .


Back to FT I am paintng climates not diectly but using the temperatures and the wettness of the territory ... though the weird thing is that in higher latitudes the more I drop the temperature Instead of taiga, ice , tundras I get desert and savannahs ... any ideas why?

I mean seems like I go tfrom hot climate desert to back to desert passing throught all the others ...


about painting temperatures, I put on the temperature map showing so all hot and cold regions of the planet , when I go to paint "Value" I set for example 18 I get a painting of a temperate green color if I paint in the equator zone but a cold bluette if I paint above the 30 parallel.

Why that? How can I do to get a more precise painting of the temperatures I want in particular areas? I tried with rise also but I got strange results that when rising a temperate zone it brought to hot then to cold if I kept pressing or viceversa

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[waldronate]

The rivers do work in Wilbur, honest. It's where the code that FT uses came from! The precipiton erosion can, amusingly enough, leave a disconnected flow system. Filling basins after precipiton erosion will reconnect the flow system, allowing rivers to run their full length.

If you have saved the river overlay channel in FT, use the Image Overlays dialog to save the overlay. Otherwise, you'll need to make a black color scheme and save the image from FT's Save As menu item. A black color scheme can be achieved in many ways, including setting the altitude color ranges to black or setting the image climate shader to a pair of black images.

FT's climate information is computed as a straight lookup into the temperature vs. rainfall table ( http://www.ridgenet.net/~jslayton/climateinfo.gif ). The impact of latitude is purely on temperature (which has some impact on rainfall as well). FT will happily place jungles at the poles if that's what you request by modifying temperature and rainfall to where jungle happens on the chart. The climate chart shows that for rainfalls less than 12.5cm/yr and temperature above -7.5C, all climates are desert; for all temperatures below -7.5C, you get tundra. If you want something other than desert, trying increasing the rainfall. Note that FT has no notion of "hot desert" or "cold desert": there is merely desert.

[Naima]

Yes but for wilbur dunno I didn't change settigns, same landscape same filled basins on wilbur the rivers are all unconnected in FT instead flow nicely .

but for the temperature I get a big problem as .... I mean for the painting tool , as you can see in the image I painted a small portion of rise temperature on the poles and instead it lowered even more ... any way to fix that?

[waldronate]

FT always does an implicit fill basin before running rivers. It automatically does this step because FT's editing data is a different resolution than the river flow finding data.

There does indeed seem to be a major bug with the value specified on the Paintbrush Options toolbar for temperature (it looks like there may be an extra C-F conversion in there). Try setting the desired amount of raise or lower via the Edit Paintbrush Settings dialog instead of directly on the toolbar (click the "C" button on the Paintbrush Options toolbar and enter your desired amount in the "Current Brush:Value" edit control). This workaround seems to get the desired effect - that is, I can set things like a 0.5 degree temperature offset and it seems to work.

[Naima]

thankyou yes using the C worked .. guess found something else to fix for next update ... ...

Edit : After an initial enthusiasm I have to say that even with the c options things are not smooth , when I get a huge transitin effect when I paint kind of distorting the brush surroundings increasing or decreasing accordingly the painting creating so an almoust impossible to use too ...

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I am starting to think that there are too many features not working properly though compared to the ones that do ... .

as for the rivers well I did fill basin right befoure , I tried also to make it several times but no effect were like the ones of FT .

btw is there a way to import and apply a mask selection over a new fractal world in order to extrude out the continents and work on them ?

this to actually "redo" the basins of my actual workd taking only the shape of the seas, rebuild fictional temporrary ocena shelves and handpaint the rest inside FT then reexport and recompose that map with the land one .



bbtw

how can I interpret the color image for alternate climate coloration ? I wanted to make one by my own and is there a limit in the texture resolution?
And why this kind of image overlay creates strange whirls and manding on closer view , but not the climate map normal colors? is it possible to create a map based directly on that last instead?
or perhaps export a map color scheme with flat surface to be used for work later in PS?

In particular also is it possible thropught C to impose a stable value to paint an area to ? like a global temperature of the area so to have as effect a translation of the relative climate without having ups and downs due to adding or removing ? I mean something like more paint only one level !

[waldronate]

thankyou yes using the C worked .. guess found something else to fix for next update ... ...

as for the rivers well I did fill basin right befoure , I tried also to make it several times but no effect were like the ones of FT .

btw is there a way to import and apply a mask selection over a new fractal world in order to extrude out the continents and work on them ?

this to actually "redo" the basins of my actual workd taking only the shape of the seas, rebuild fictional temporrary ocena shelves and handpaint the rest inside FT then reexport and recompose that map with the land one .

Try Select>>Altitude Range with 0 as the minimum and a large number such as 1000000 as the maximum. This operation will select just the land at the current editing resolution. Then use Select>>Save Selection to save out that selection with a file name of your choice. Any time you want to restore that selection, use Select>>Load Selection and select the file that you saved previously.

bbtw

how can I interpret the color image for alternate climate coloration ? I wanted to make one by my own and is there a limit in the texture resolution?

For the Image Climate shader, provide an image of whatever resolution you like (if it gets too large, FT will crash). You should be able to load an image of at least 4096x4096 pixels.

And why this kind of image overlay creates strange whirls and manding on closer view , but not the climate map normal colors? is it possible to create a map based directly on that last instead?

It's not an image overlay, it's a shader (an image overlay is a picture that gets drawn on top of the globe without regard to the underlying shading). Recall how the climate shader works: FT calculate the average annual rainfall and average annual temperature at a point. These inputs are used as indices into a 2D table to get a single climate type. That climate type is then used as a lookup into a 1D table of colors specified in the world settings. The Image Climate shader is a little simpler: it uses the average annual rainfall and average annual temperature as direct lookups into a 2D color table (the image that you load). The more pixels that you have in your image, the more possible little patches of color that you have.
FT also sports the Texture Color shader, which is much like the regular Climate shader in that the temperature and rainfall are used to look up a climate type. Instead of then using the climate type as a lookup into a 1D table of colors, the Texture Climate shader uses that climate type into a 1D table of textures, which are tiled uniformly across the output. So all areas with forest, for example, will get one texture; all with desert will get another, and so on.

or perhaps export a map color scheme with flat surface to be used for work later in PS?

I don't understand this statement.

[Naima]

Ok thanks , but about the climate painting? Is there a way perhaps to paint externally temperatures and wet level and obtain a similar climate result? Perhaps a small painting tool in quch to project a lookuptable as the one i ft seems not going well?

[waldronate]

Ok thanks , but about the climate painting? Is there a way perhaps to paint externally temperatures and wet level and obtain a similar climate result?

There isn't a way to import maps other than altitude maps, sorry.

Perhaps a small painting tool in quch to project a lookuptable as the one i ft seems not going well?

If I understand this request, what you would like is a painting tool that will adjust the local area's temperature and rainfall so that the climate moves toward the nearest climate of the selected type. For example, if you paint "forest" into an area of "tundra", the system will adjust the rainfall and temperature to the nearest point on the climate lookup table that is "forest". Unfortunately, this change will leave a ring of other climate types around the edges of the brush. I've implemented this before (in a very slow fashion), you see, and I really didn't like the bullseye climate effects.

One thing to try with the temperature is to use a value on the edit dialog of about 0.1. The temperature is raised by that amount every time the cursor moves a pixel, so they all add up quickly.