Not sure what you mean by the "right range". Terragen doesn't care what resolution or height range is represented in the file, generally. The reason you need to multiply is because this terrain (image) format doesn't have built-in scaling values. .ter does, and others can too (.tif with georef data, i.e. geotiff). EXR can be used too, with meter values instead of 0-1 color values, but that's not a standard.
Anyway I would guess these artifacts are part of the original heightfield. That could easily be checked in e.g. Wilbur (free terrain editor/viewer).
- Oshyan
The range are clamped values, which do effect even a TIFF output.
Take a look at Quadspinner's documentation:
https://medium.com/quadspinner/terrain-scaling-33e6fc35c7a9From what I'm looking at here, compared to a 4k heightmap in TIFF format from the same application, his heightmap is clamped and not full range.
In TIFF format, this will effect the desired scale range because of inherently how TG reads it expecting it to be 0-1 range.
Edit: That being said, small, low scale details
will not be appropriately represented in a 0-1 range when clamped in TIFF format. Being barely present and/or clamped/cut off, they will be exponentially effected by scaling up the terrain in Terragen beyond it's read 0-1 range.