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    sculpt below landscape

    I create landscape using hightmap and now I cant sculpt below landscape why?

    #2
    Hi,
    I cant sculpt below landscape
    What do you mean? Do you mean you can't sculpt the landscape at all, or do you mean that you can't sculpt the landscape below a specific point, or...?

    Basically the landscape heightmap is 16 bit (so you've got something around 65000 different heights) and dark (0,0,0) is the lowest height (you can't go below that) and white (1,1,1) is the highest height (you can't get above that). Sculping means painting on that greyscale texture. The actual min and max height of your landscape depends on your z-scale. By default (z-scale = 1.0) dark (0,0,0) is -256m and white (1,1,1) is +256m. If you import a heightmap, and it already contains a pure black value (0,0,0), then that would mean that you can't sculpt below the lowest point of your landscape. Is that your problem?

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      #3
      Originally posted by chrudimer View Post
      Hi,


      What do you mean? Do you mean you can't sculpt the landscape at all, or do you mean that you can't sculpt the landscape below a specific point, or...?

      Basically the landscape heightmap is 16 bit (so you've got something around 65000 different heights) and dark (0,0,0) is the lowest height (you can't go below that) and white (1,1,1) is the highest height (you can't get above that). Sculping means painting on that greyscale texture. The actual min and max height of your landscape depends on your z-scale. By default (z-scale = 1.0) dark (0,0,0) is -256m and white (1,1,1) is +256m. If you import a heightmap, and it already contains a pure black value (0,0,0), then that would mean that you can't sculpt below the lowest point of your landscape. Is that your problem?
      yes exacly its my problem, i was have white and black hightmap white was mountains and black was lake, and i want make this lake more deep, its any trick to do that?

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        #4
        Originally posted by yoyomadafaka View Post

        yes exacly its my problem, i was have white and black hightmap white was mountains and black was lake, and i want make this lake more deep, its any trick to do that?
        You can export the heightmap of your landscape from unreal engine. Then open it up in a image editing program that can work with 16 bit images (like gimp) and change the heightmap (lower the contrast, at best in a way that you know how much the range has changed as you would need to properly increase the z-scale of your landscape to compensate for the lower contrast in the heightmap). Then import that new heightmap again and change the landscape z-scale accordingly.

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          #5
          "yes exacly its my problem, i was have white and black hightmap white was mountains and black was lake, and i want make this lake more deep, its any trick to do that? "
          That is exa ctly what I'm trying to do, to lower ( ctrl LMB) terrain for targeted lower depth of some areas, but I can't. If I create a new projevt, new terrain, I
          CAN lower terrain via sculpt, quite a ways, so why do some terrains allow this and some don't it makes no sense.

          I'm using world comp with 4 tiles, is that part of the proiblem ? Z value for tile 0 terrain that won't let me lower terrain is 149.300034, is there a value that I need to change that to SO I can sculpt down ? No values I've tried alters it so I can do that.

          So counter intuitive to design , causing me giant headaches. I guess I could export and import and edit, but that's far from an ideal solution as its hard to 'see' where I'm sculpting in detail as I would in realtime 3d in engine.

          BTW, "as you would need to properly increase the z-scale of your landscape to compensate for the lower contrast in the heightmap", not sure what you're getting at here could you rrephrase pls))), Then " Then import that new heightmap again and change the landscape z-scale accordingly ", how would one know what value to use ? Does gimp have an abillity to visually show what value has changed on image to then relay to ue4 terrain ?


          thx

          Last edited by neighborlee; 09-18-2020, 07:56 AM.
          Solo but Seismic - feel free to apply
          https://neighborlee1.wixsite.com/theheartseed

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            #6
            so why do some terrains allow this and some don't it makes no sense.
            I tried to explain that a bit in my first post =)

            Basically UE stores the height information of the landscape inside a 16 bit greyscale texture. That means that you're limited to 216 - 1 = 65535 unique height values. Now you need a way to distribute those 65535 values. By default the landscape has a range of 512m, so -256m as lowest value and 256m as highest value. So that would be approximately 512m/65535 = 0.78125cm between each value. Now you can change the z-scale of the landscape to lower or increase this height range. For example if you would set the z-scale to 2.0, then that would mean that the height range is now 1024m, with -512m as lowest and 512m as highest value. But since you still only have 65535 height values, that means that the stepsize is now 2*0.78125cm = 1024m/65535 = 1.5625cm.

            So by setting the z-scale of your landscape you have also set the maximum and minimum height value of your landscape. Changing the z-scale of your landscape won't change the heightmap texture of your landscape. It will only change how those values are interpreted.

            is there a value that I need to change that to SO I can sculpt down ? No values I've tried alters it so I can do that.
            AFAIK there is no way to shrink the heightmap in UE, so you would need to export the heightmap of your landscape and do it in an external program.

            "as you would need to properly increase the z-scale of your landscape to compensate for the lower contrast in the heightmap", not sure what you're getting at here could you rrephrase pls)))
            Sure. Imagine your landscape has used the whole available range of 65535 values, so you have a pure black and a pure white value in your heightmap. That means you cannot sculpt any lower or higher. To be able to sculpt lower or higher, you would need to free up some of those 65535 values. You would do that, by lowering the contrast. For example you could shrink those 65535 values onto 32768 values. Since you still have the same stepsize that would mean your landscape has now only half its previous height. Therefore you would need to double the z-scale of your landscape to compensate for that. Now you will have the same landscape (but with half the height precision you previously had) but you have now doubled the available range and can therefore lower the lowest value or increase the highest values again.

            how would one know what value to use ? Does gimp have an abillity to visually show what value has changed on image to then relay to ue4 terrain ?
            No idea how to do this in gimp. I use tensorflow if I want to script operations on textures. There I would import the texture, divide by some value, lets call it "n", add an appropriate value (65535/(2*"n")) to recenter it, then import to UE and multiply the z-scale by "n".
            Last edited by chrudimer; 09-18-2020, 12:06 PM.

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              #7
              But hightmap should only create shape landscape like you create shape using sculp, this is so stupid, I cant edit hight map becouse how? I cant make black more black?

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                #8
                I cant edit hight map becouse how? I cant make black more black?
                Yep, that about sums it up.

                But hightmap should only create shape landscape like you create shape using sculp, this is so stupid,
                I didn't build the system =)

                But with sculpting models you're only moving vertices, that's why after sculpting a high poly model you go through the fun of making another low poly model / retopologize. That won't be feasible for the landscape, especially since you don't want any popping when changing the LoD. The landscape changes the poly count fluently during LoD transition. But yeah, it would be great in this situation if epic would store the heightmap also in 32 bit and then make some button to change the min max range of the 16 bit heightmap. Cause every time you rescale your 16 bit heighmap, you loose some information due to precision, therefore you should choose your min max height of the landscape at the beginning.

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                  #9
                  You know this would be al fine and 'logical' but if I make a new terrain in a new world in say , world comp, I CAN sculpt below the terrain, but I can't do that in my 2 yer old terrain project,so why ? What values are being used in my old project that prevents it, and what values are being used in new project that allows me to do so ? That is the strangness that makes no sense, as the same values in placement rotation and scale , in new project are the same exact ones in older project.

                  BUt ya 'changing' the vaues at the beginning is horse pucky (* again you didn't design the system) because as evvvveryone knows, thats not always how design, art, works. Yes for sure, why they didn't make this easier for artists and all others is beyond stupid. I, we, shouldn't have to be sitting here ready and eager to make new ART, games, incredible they are at least to us and have to be held back by this crud Maybe I should post on new features, I will, maybe then finally somebody will address this.
                  Last edited by neighborlee; 10-07-2020, 10:16 AM.
                  Solo but Seismic - feel free to apply
                  https://neighborlee1.wixsite.com/theheartseed

                  Comment


                    #10
                    Originally posted by yoyomadafaka View Post
                    But hightmap should only create shape landscape like you create shape using sculp, this is so stupid, I cant edit hight map becouse how? I cant make black more black?
                    THIS, I get the 'system' and its deficiencies, but THIS.
                    Solo but Seismic - feel free to apply
                    https://neighborlee1.wixsite.com/theheartseed

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