Is there any aternative heightmap softwares than World Machine?

Im using UnrealEngine for VFX and outdoor simulation, so Im wondering if there is a easy way to get a decent heigtmap for terrains than using World Machine. I find World Machine abit complicated. I see Terragen is now £299 for a limited time, that isnt that expensive, but does anyone know how the
workflow with Terragen and UE4 works?

terragen is a great piece of software but does not play well with others. its intended more for final renders.
infact there is no mesh or map export as such. there is a node called microexported that uses the camera viewport. the region rendered out is what you end up with.

here is a very good breakdown of the terragen to realtime application:

you can definitely pick up some tricks from it but the general consensus is that is still not ideal for authoring rocks and cliffs.

WM is your best bet for height maps. TG is quite good for larger rock formations. they work well in tandem.
a benefit of TG is also its cloud/atmospherics engine. its incredibly awesome.

fyi i found WM to be a piece of cake compared to TG. rendering in TG is quite slow which makes iterating on your displacement excruciating.
VUE is a an alternative but i advise you to stay away from it.

pm me if you need wm help.