Remove border issues on terrain

[DavidKossowsky1]

I'm trying to place a height map/terrain image (it's an obscure shape with transparency) in CityEngine but whenever I add it I end up with strange height extrusions around the border of the image. I've tried to export the image as cleanly as possible without anti-aliasing/compression, etc. and I've saved it as a PNG-32 with transparency, but whatever I do ends up with the following result:

Is there any way to tell CityEngine to ignore or clip out the messy border on my terrain? Or is there another way to prep the file so that this issue doesn't occur?

Thanks

[LR]

Turn off value filtering in the inspector.

[DavidKossowsky1]

I tried that and it helped somewhat, but it didn't fix the problem entirely:

[LR]

Are you sure your edges don't have half-transparent pixels? Can you post the image?

[MatthiasBuehler3]

hi .. NaN values are most probably the issue. Fill in the missing pixel values. CE does not create polygons there.