Negative heights

[MathemanFlo]

The current height painting worflow does not work well for "digging holes" or stamping details. The user has to paint a height of 0.5 on the base layer to be able to ditch in the surface afterwards. Therefore it might be a good idea to support negative heights. This idea was already proposed in https://github.com/armory3d/armorpaint/issues/1227#issuecomment-1003049600 I looked up how it is done and it seems to be rather simple. The interval [0,1] of traditional height maps is simply mapped to [-1,1]. I.e. the old 0.5 is the zero-level. Source: https://substance3d.adobe.com/documentation/spdoc/height-map-painting-29130786.html