View Full Version : Creating a Planet Texture
12-18-2010, 02:29 PM
Ok I need a little help from you Gimp and Photoshop guys.
How would I go about converting this to a planet texture map.
I can do all the colouring, but the stretching this into the right shape has got my fibromyalgia mind stumped atm, and I sort of need it reasonably quick.
12-18-2010, 04:38 PM
Anyone who knows me knows what I'm about to say :) First, because of the small size of the landmasses double the size of the image. Second, put your landmasses on their own layer...lots of ways to do that so I won't take up space here by describing them all. New layer, filter - render - clouds. Duplicate this layer then do render - difference clouds 2 times. New layer, fill with black, decrease opacity to around 75%. New layer, ctrl-click your landmass layer then select - modify - expand - however much you want to expand by, select - feather - same as the amount you expanded by, fill with white, reduce opacity to around 25%, then click on the black layer and hit the delete key, then deselect. New layer then hit ctrl+alt+shift+E then filter - render - lighting effects (make sure that your light covers the whole image and also use a texture channel and click on "white is high" and move the slider to "mountains". The mountains might be out of place but you can delete this layer and go back to the clouds, black, or white layer and manually airbrush in some white or black to put the mountains where you want them. Here's an example. In my example I crop the land layer to fit the selection of the landmasses and put a black layer underneath (ocean coverup) then used an expanded and feathered selection (both 100) of the landmasses to delete holes in it.
12-18-2010, 04:47 PM
Thanks Ascention, that side of things Im pretty ok on, what has got me at the moment is stretching out the zigzag map, and where the islands are cut into, with it into one continuous rectangle so I can use it to wrap aroung my sphere texture so I can render it, the creating of the textures for the islands Im fine with, but its rejoining the islands and the seas so they will be in the right place on the sphere.
I tried using the warp function but it seems to be beyond me atm, maybe its the cold weather affecting my mind.
Think of the image I posted as an orange peel that has been peeled off an orange, well I need to fit it back on the orange.
I hope I was a little clearer this time.
12-18-2010, 05:00 PM
Oooohhh, right. So it's not a texture thing it's a projection thing. What needs to happen is to progressively warp things more and more the farther you get away from the equator...so that those edges join up. I'm guessing some other program would be needed for that 'cuz I've never figured out how to do it in PS alone. There are some programs out there, like Fractal Terrains, that render maps already warped (for fitting to a sphere) but to take an input image then warp it...I don't think that can be done. I'll bet someone here knows, though.
12-18-2010, 08:09 PM
I had a look at this and quickly surmised it's way beyond my abilities. Waldronate would be the best person to ask.
12-19-2010, 01:12 PM
Yikes !. I agree thats a tough one. I think there are two possible ways to do this. The first is to find which projection this is made in. You may have that info or else because the shape is somewhat unusual I would think it would be fairly easy to look it up in a list of map projections. The wikipedia has some good links on that. Once you have it then you should be able to get a program which changes map projections. I think Waldronate is the king of this type of thing here and I think his apps like Fractal Terrains and Wilbur have some projection stuff in them. There are also other programs that have been mentioned on this forum in the past. What I would do is find the name of the projection and get one of these apps to render out a sample of it so that it gives approximately the same style image. Then adjust yours to match the one rendered out getting the pixels lined up. Then import the new adjusted bitmap into the app and set its projection so that it can render out the sphere.
The other way is equally as difficult if not more so. But you could get a 3D app like Blender and get it to create a ball and render out the texture for the ball as a UV map. Then taking your image you would need to set up the pixels to UV coord mapping and then apply that texture to the ball again.
Best of luck, id be interested in seeing if / how you manage it.
This may help:
Actually, I am looking at this map and there is something wrong about it. The axis for longitude is equal spacing as is the latitude so this would imply that the position say at lat / long 30, 0 does not exist. Maybe the border to the region is not a projection - but then the shapes which are interrupted seem to join up. This would imply that across the interruption is the same coord so therefore it cant have a linear scale. I don't get this at all. I think its been mangled. I dont understand enough about projections to be confident about that tho.
12-19-2010, 02:02 PM
I think its been totally mangled, I dont think its based on any mathamatical procedure at all just what the artist thought would look good.
I may just have to use the smaller scale maps I have of the islands to piece together the whole thing.
12-19-2010, 02:11 PM
If you take the El Mar Del Sur from this map and look at a smaller joined up version, does it appear that the island broken is split and separated onto the two leaves of this projection or does it appear as though this projection has merely been masked over the top and the whole middle of the island is missing from it ? Could you, for example, take this map and join back up the two halves and would they then sit on top of the other smaller scale version without being warped by some projection ? I'm just curious whether this projection is real or just some kind of outline placed over the map and labeled up as one. Its a well strange situation going on...
12-19-2010, 02:25 PM
It's not a "real" projection in the sense that it is mathematically stretching a sphere onto a plane. It looks like someone was inspired by Goode's Homolosine projection and did something vaguely like that, but without an understanding as to WHY Goode split the map the way he did.
One possible way to try to get things back together (assuming that you don't have local-area maps) is to print the map above, fold it so that the split areas line up, then take a picture of the area of interest. There will be some distortion, but it's a realtively low-tech way to get the source info back.
The other way, of course, is just to slice and dice in an image editing program.
12-19-2010, 02:25 PM
theres no piece missing the artist who did this decided to split the island in half in a few places, its a shame the original artist isnt working on this, but its poor old me instead. Im trying atm to stretch the map around so I have the aproxamate location of where everything should be, I have all the blown up maps of the islands, so I should be able to replace them on the map in the position they should be in, and then go from there.
12-20-2010, 02:41 PM
Well this is what I have done to try and work out what goes where.
I know ir looks a little mad but I think it will work, I can cut and paste off the original map and set the islands in the areas that now seem to be the plave for them.
12-21-2010, 02:47 AM
I gave it a little effort and came up with the attached. I unprojected chunks using a Hammer projection. It's not perfect (it's pretty bad in places), but it seems to be reasonable on a globe. I'm not sure how good it is in absolute terms, though.
12-21-2010, 07:52 AM
Waldronate thats amazing, thank you so much
12-21-2010, 12:23 PM
Here's the first preliminary render to see what its going to look like.
All ive done so far is to clean the map. define the caps and green out the islands, I added the sea colour, but have not created the shallows around the islands.
12-21-2010, 01:50 PM
Knitted together, the meridians appear approximately elliptical(or quartic or something, but let's not get crazy), the parallels are evenly spaced. If I were forced to shove that into a mathematical projection, I'd go with a bizarrely interrupted Apian II (http://www.giss.nasa.gov/tools/panoply/help/projections/apian2.gif). I don't know of any app that takes arbitrarily interrupted projections(of any sort) to reproject.
My suggestion, rather than trying to reproject or warp or slice-n-dice this map, would be to start with a blank page twice as wide as it is high. Treat that as equirectangular or geographical projection with equally-spaced straight parallels and meridians perpendicular to each other. On that sheet draw, by eye and imagination your best approximation to the island forms on the map, Remember to try to take into account the east-west stretching that will occur as you move away from the equator.
What you get won't be a perfect reproduction of the landforms in the existing map, but they are clearly, themselves, not a perfect reproduction of any land that could exist on the surface of any sphere.
Once you have a master in equirectangular projection, it's pretty easy to find something that will project that into a whole lot of other projections. FT Pro is good for that. If you want to get a lot more technical, Proj.4 (http://trac.osgeo.org/proj/) is a good free app, but not necessarily easy.
EDIT: I should make sure there isn't a second page before I post :roll: .
Both Waldronate and Digger seem to have this well in hand. Neither of these are necessarily going to fit the intention of the map's author, but neither does the author's map so hey... it's 8) .
This map is what happens when graphic designers do cartography :P . Graphic designers on this board are of course excepted. People on this board pretty uniformly have a respect for maps.
12-21-2010, 04:51 PM
Will concentrate on the Islands now, I have detailed maps for all of them
12-22-2010, 10:15 AM
When the maps all completed, what format would you recomend to redisplay it as a flat map and is the a programe to do it?
01-18-2011, 10:00 AM
This is where I stand atm with the map
01-20-2011, 09:13 PM
Well Done Digger! Do you have a heightfield (greyscale image)? I could generate a pretty detailed image with (grass/rock/etc) textures for you if you did.
Oh, Hi. I'm lurking around here now. Good to see more of your work.
01-20-2011, 11:12 PM
Not knowing the first thing about any of the math involved in this I'm just going to say it looks very nice :) (and go stick my head in a book..a book about math..a book about math and maps...) :)
01-21-2011, 05:47 PM
Its not a brilliant height map, but here it is.
08-25-2011, 07:07 AM
Not a full solution for YOUR problem, but it's one way of solving it: Unwrap the object to the shape of your map. Most 3D-modelers have this tool (3DSMax is reasonably simple). It flattens the mesh over an existing bitmap.
This flattening of the mesh will not place itself automatically right over the map, but you can edit the flattened sphere mesh to match the shape of this projection in the unwrap editor.
I don't know exactly how to do this at this time and, and might not get around to make an example to show you within a reasonable time. So just take this as pointing a finger in a direction. Maybe someone else can come up with the example before I can.
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