Exactly what you described. I wanted to use it for the mask in Unreal for the layers. When I tried to update it using raw files UE4 doesn't seem to recognize their sizes and fails. Which is really strange, because can "sometimes" use the raw file to create landscape for the very first new landscape, but trying to update the layer using exact the same map fails for some reason. When I convert the raw file into png 8bit , it worked.
Also for height map png 8bit, it should be gray scale png. A normal color png works for UE4 but shows annoying warning message every time I try and import it for the layer mask.
Agreed - raw files are usually good only as a last resort. However, usually 8 bit height maps are insufficient vertical precision and thus not very satisfactory. Are you sure you want to use these over 16bit PNGs? Regardless of its suitability for terrain, I agree, at a minimum it would be useful for masks and such. Will put it on the feature request list!
We need ability to export 8bit PNG height map. Unreal editor doesn't work well with raw files for determining the size of the texture. We can ofcourse, use photoshop to convert it, but it would be super nice to be able to export heightfield as 8bit png file.