Map splitter cumulates error

Hello everyone,

We are using PLSM2 for a while and we just noticed we have some problems on our maps. The ground gets bumpy. To recreate the problem run the mapsplitter over and over again on the generated page map and it seems it creates a small cumulative error, getting worse and worse. I thought first it could be some kind if precision loss but I expected it to happen only once instead of being cumulative.




PageSize=2049
ScaleX=2749.3418
ScaleY=1530
ScaleZ=2749.3418

It is a 16bit heightmap


This is a diff with a boosted contrast of the original and the first iteration, hard to see but there is a difference.
http://www.wendigostudios.com/upload/PLSM2/diff_0-1.png

This is a diff with a augmented contrast of the original and the sixth iteration. The difference is much more apparent.
http://www.wendigostudios.com/upload/PLSM2/diff_0-6.png

Anyone has any idea about this?

We temporarily patched the problem at adding a post process in the pipeline.

Save .modif -> compare each pixel of original with .modif's -> output modified pixel only if modified by at least 2 on 65535.

Which mean it will ignore changes of 2 centimetres only in our scale.