Keep in mind that Houdini Apprentice has a maximum output resolution of 1280x720. This is enforced globally, so applies to things you may not think of as “images” such as heightfields or ocean spectrum.
https://www.sidefx.com/filmtv/compare/ [
sidefx.com]
You can always output a resolution that fits, then use your favorite image program to resize it to the 1009x1009 you need for unreal.
Attached is an example of rolling your own save of a heightfield as an image. This is useful if you need more control than the terrain output gives; or if it seems to not be working for you…
After the heightfield_noise, you'll see a COP2 Network called “prepare_to_export” Dive into that and you enter our compositor. You will want to change your viewer from a 3d viewer to a compositor viewer. Above the 3d viewer is a series of tabs, one of which is “Composite Viewer”. Switching to that and you get a 2d composite view of your height field.
The SOP Import node takes the heightfield from geometry land into texture land. There is a path on it pointing to the heightfield_mask controlling where it imports from. There is also buttons to adjust the resolution to match the incoming heightfield, you'll have to reset this if you change the res in geometry land.
Here you can do all the post-processing you like using 2d image tools. In this case, I use a bright to get the meter elevations remapped into a 0..1 range so the PNG can save the data. Finally a ROP Output saves a test.png.
One thing you may run into building your own sequences or working with height data is that 8-bit formats are often sRGB, but height data is always linear. So you may have to disable the “COnvert to image's colour space” to avoid gamma remapping.