A few questions about terrain size

Hi All,

So I’ve started looking in to using UE4, and I’ve got a bit stuck with Terrain sizing, in particular, what determines the actual, physical size of a terrain Within UE4 itself.

I come from a background of terrain making within the Arma series of engines, and we handle things a bit different, specifically, we specify a heightmap resolution, and a cell size, and these multiplied together give me the physical size of the terrain, for example 1024x1024 with a 5m cell size, I have a 5.1km terrain.

The way I see it now, is if I have a 1009x1009 heightmap, and import that in to the unreal engine, there is no equivalent of “cell size” the terrain imported is simply a 1:1 scale, meaning my terrain is going to be 1009x1009, is this correct? I’m pretty handy with L3dt, and just started using world machine, so any pointers for using those with UE would be great, sorry if these are pretty n00b questions, so but I’d like to get an understanding of how this all works before trying it out and banging my head against a wall because I’ve missed something fairly trivial.

Many Thanks

Anyone? :expressionless:

Check out the Landscape docs as they a lot of information on topics like this.

Thank’s ,

I have read those docs, and unless I’m missing something fairly basic they don’t really go in to much details about what the problem is I’m having, quite simply, if I import a heightmap from world machine, that is 1009x1009 and is set within WM to be 8km x 8km how do I set that 8km x 8km size in UE4, leaving the heightmap res at 1009x1009 and the scaling all set to 100 brings some issues, the height is all over the place, sometimes way to small, sometimes way to large, and the terrain is definitely not 8km x 8km as I can walk around the entire terrain in a minute or so…

The scale factor of the landscape actor is the distance between landscape vertices in unreal units. Compared to ArmA, having a scale of 500 on X any Y axis would mean that the quad (cell) size of the landscape is 5 meters. By default the landscape has scale factor of 100 on every axis, which means the quad size is 1 meter.

When you import a heightmap, you just need to know the XY resolution. If the heightmap is 4 meters per pixel, you scale your landscape to a factor of 400 on X and Y axis. I believe the engine automatically pads the imported heightmap to match the dimensions of UE 4 landscape.

I haven’t found a nice way to scale the height of the landscape yet, I just eyeball it usually and guestimate using the ruler tool and adjust the Z scale accordingly.

Thanks for that pretty much exactly what I thought, so basically whatever the per pixel resolution is in WM… for example my test map is 3.94m per pixel, that then becomes the x,y scale multiplier, mine would be 394 for x,y ? and yes Z scale seems very touchy, where do I find the ruler tool btw? it’s escaped me !

I eyeball as well because that’s the final judge anyways. If your terrain is numerically accurate and looks off- that won’t help anyone.

If you go into top view. Click mouse wheel drag on the map it should start to draw a line with unit size.

I’m learning UE. I just read:

What I’ve got is component size is based on the number of quads in a component. What this documentation does not tell you, at least I did not see it is what size is a quad? I understand it depends on if you have 4 sections per component, you’d end up still calculating the number of quads per component.

You are creating a project, and you want a map/level that is for an example 1 km x 1 km. How many quads is that?

I’ve also read this link:

It basically says that if you have a landscape size that is
56x56 quads, you’d have a dimension of 56 x56 meters.

And if your landscape is 1016x1016 quads you have a dimension of 1016x1016 meters, approx 1 square km, if I’m reading his table correctly.

Is it as simple as to say that quad size is fixed, and If you are looking for physical size of a landscape, that quad total x times quad total Y will give you the size of the terrain in square meters?