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"Cut-out" effect

Hi everyone,

I am trying to make a path paved with bricks/stones that is similar to this Skyrim screenshot:

TESV%202014-07-28%2006-12-44-92.jpg


In this screenshot, it almost looks like the "stony" part of the path is a separate piece of geometry from the terrain that it's resting on. That is the exact effect I am trying to achieve.

But, whenever I paint textures onto a terrain in any engine, the edges of the textures always come out fuzzy, not sharp and separate like they are here. This does not look good when I am trying to use a texture to create the effect of a road paved with stones.

Sorry I am new to this and I am completely stumped: how do you achieve an effect like this, as if parts of the texture were "cut out" so precisely? Is it done with special shaders?

DO you use separate geometry, and, if so, how do you ensure that it follows the exact curves of the terrain so well?

Replies

  • JoshWilkinson
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    JoshWilkinson polycounter lvl 9
    What engine are you using? This can be achieved with vertex paint to transition the two materials and parallax to give the stone more depth (simulated geometry)
  • throttlekitty
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    throttlekitty Polycount Sponsor
    You're talking about the transition from the stone to the dirt, right? It depends on how the engine is configured, the basic idea is that you have an opacity map to dictate how blends look.

    http://www.gamasutra.com/blogs/AndreyMishkinis/20130716/196339/Advanced_Terrain_Texture_Splatting.php
  • sargentcrunch
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    sargentcrunch polycounter lvl 10
    Here is how Skyrim does it, its a separate mesh with another texture. I can't post the texture flats, out of respect for Bethesdas content, but they are both tiling textures

    153060bc9d.jpg


    EDIT: They also have 30 different pieces for the modular kit, they sink these into the ground to blend in with the landscape.

    a868390484.png
  • anton_s
    Thanks for the replies everyone, these have been very helpful!

    The engine I'm doing this in is Unity (not my choice, I have to use it). Throttlekitty, I took a look at the Gamasutra link and it looks like that algorithm would be able to convey the effect I'm looking for. Ugh too bad I don't yet know much about writing shaders... and I am on a time crunch to finish this thing for a project I am working on.

    Sargentcrunch, thank you for the info. I thought Skyrim might have been a using a separate mesh for the road, but what I was confused about is this: in my screenshot and in the game itself, most parts of the road seem to be very long, continuous meshes that follow the curves of the underlying terrain perfectly.

    When the road goes uphill the mesh goes uphill with it, when the road is slanted, the mesh is also slanted at the same angle etc.

    I am assuming the terrain was generated in an engine. So to get that seprate road mesh, would you e.g. import the underlying terrain into 3ds max, then extrude the parts you want to be the road mesh, and then reduce the geometry until it is optimized like it is in your screenshot? Wouldn't that take a very long time, and wouldn't it be hard to make modular re-usable meshes that way? Would you use scripts to help with this process?
  • EarthQuake
    You can do something similar with decals and an alpha map. Does unity have a decal projection tool?
  • passerby
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    passerby polycounter lvl 10
    Ya unity has a decal projection tool EQ, works with any shader type as well, alpha, additive, multiplitive etc
  • sargentcrunch
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    sargentcrunch polycounter lvl 10
    anton_s wrote: »
    Thanks for the replies everyone, these have been very helpful!

    The engine I'm doing this in is Unity (not my choice, I have to use it). Throttlekitty, I took a look at the Gamasutra link and it looks like that algorithm would be able to convey the effect I'm looking for. Ugh too bad I don't yet know much about writing shaders... and I am on a time crunch to finish this thing for a project I am working on.

    Sargentcrunch, thank you for the info. I thought Skyrim might have been a using a separate mesh for the road, but what I was confused about is this: in my screenshot and in the game itself, most parts of the road seem to be very long, continuous meshes that follow the curves of the underlying terrain perfectly.

    When the road goes uphill the mesh goes uphill with it, when the road is slanted, the mesh is also slanted at the same angle etc.

    I am assuming the terrain was generated in an engine. So to get that seprate road mesh, would you e.g. import the underlying terrain into 3ds max, then extrude the parts you want to be the road mesh, and then reduce the geometry until it is optimized like it is in your screenshot? Wouldn't that take a very long time, and wouldn't it be hard to make modular re-usable meshes that way? Would you use scripts to help with this process?

    You can see they have slanted road pieces, they probably have rules they use on the terrain, plus they can get away with a bit of scaling on the ramp pieces before it starts looking stretched.

    Like I said, they have 30 pieces that cover all the stone roads in the game.

    What EQ mentioned would probably be a better solution if you didn't want to limit your terrain to certain angles, etc.
  • throttlekitty
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    throttlekitty Polycount Sponsor
    Make terrain, place road meshes, adjust terrain. MIIIIIND BLOOOOOOWN
  • Neox
  • chrisradsby
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    chrisradsby polycounter lvl 11
    they're probably using some kind of terrain splines? That places a decalled road along the terrain or deforms the terrain after the spline.
  • anton_s
    OK thanks you guys this was very helpful. I ended up using shaders to get the effect I wanted (with help from a friend):

    oz.JPG
  • throttlekitty
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    throttlekitty Polycount Sponsor
    they're probably using some kind of terrain splines? That places a decalled road along the terrain or deforms the terrain after the spline.

    I've used the Creation Kit for Skyrim, I'm %99 positive those are hand placed.
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