# UDK landscape - heightmap scale

polycounter lvl 10
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polycounter lvl 10
Heya PC

I come here with a bit of a question, I'm prepping to start working on an environment in UDK and the basis of it will be centered around an island. To be specific its the "Old town" island in Stockholm. I've read up and learned about how to create and sculpt the landscapes, how to import heightmaps etc etc. But what I'm a bit stuck at is planning up the right size to go with.

So, here's a rough picture of the island layout from the era the environment will be set in:

I've calculated that I'd need a map which creates a landscape which is roughly 2000 square feet. But digging through the documentation most of the landscape maps are sized like 4033x4033, 2017x2017, 1009x1009 etc. And that doesnt really say "how large they are" or what their corresponding unit size is. Does anyone know a good way to calculate this? Because I'd want to get as close to true size with the island as possible. Or would you advice me to take another approach?

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polycounter lvl 8
Grid size in unreal is 524288 x 524288 uu which is approximately 10,5 km x 10.5 km if you take scale that Epic uses where 1 uu = 2 cm. Landscape of 4033x4033 fills almost whole grid, I'd say its roughly 10 km x 10 km in size. So you just scale down from that. 1 square meter = 10.7639104 square feet

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polycounter lvl 10
Okay, so since I just need about 1 square kilometer to fit in the islands then 1/10 of a 4033x4033 would do. Closest usable size for a landscape is a 505x505 or a 509x509.

Thanks for the help
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polycounter lvl 8
Yes, and you can always delete the components you don't need.
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null
how do you know that 4033 * 4033 = 10 square kilometers. I dont wanna be a smartass just curious about the math behind it.

Im cooping with the same problem as the OP trying to find a good measurement to start my landscape with but 4099 * 4099 vertices doesnt tell me anything.
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polycounter lvl 8
It's just based on a scale that Epic uses where 1 unreal unit = 2 cm, so since maximum grid size is 524288 x 524288 uu, that's 1048576 cm x 1048576 cm, or approx 10.5 x 10.5 km.
Largest landscape you can create in UDK is 4033 * 4033 vertices and when you go to the top viewport you can see that it almost fills up the whole workable grid with slight gap left between borders. So it's somewhere around 10 km x 10km (so 100 square kilometers), with 100-200m error maybe even less.

If you want you could calculate accurately it in meters by measuring width of the gap between the grid border and far edge of the landscape using middle mouse button from top viewport. Once you've got that just multiply with 2 (for the gap on the other side of the grid) multiply once more with 2 (to convert uu to cm) divide with 100 (cm to meters), and subtract that all from grid width (10485.76 meters). In short:

Max Landscape Width (m) = 10485.76 m - (gap width * 2 * 2 / 100)

But instead of having something like 10076 or 9912 meters, i'd say having it as 10 x 10 km is more convenient and good enough for an approximation.
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interpolator
Keep in mind as well that UDK scale is what you make of it. Landscapes, like any object, can be resized once created. You can base the resolution of the landscape off of the height map you're using to import, then resize the landscape itself as you see fit.

While creating a landscape with a higher vert count will give you a larger landscape by default, there is nothing saying that you can't resize it and have a small area be very dense or a large lanscape have spread out details. If you're importing a GIS heightmap you're limited by the initial resolution (vertices) but not by size (considering it doesn't go past the viewport range).