Increasing Terrain Surface Smoothing Breaks 3D View

[theodson]

Hello,

I'm attempting to learn the terrain modelling  techniques to best map my current landscape/terrain before embarking on modelling the existing house (I've placed a simple building to give context only).

 

To learn what works and doesn't, especially with terrain breaks and retaining works, I've selected the lowest terrain specification options ( LOW Triangle Count and LOW Terrain Smoothing). This works well and 3D camera views are great.

 

Whenever I attempt to increase the Triangle Count to MED or HIGH this seems to break things (introduces strange 3D artefacts) and the 3D camera view has extreme high and low elevation points. It also seems to introduce numerous contour lines near the terrain boundary that relate to these spikes and troughs.

 

These pictures show the settings and what I've tried to describe.

 

[theodson]

The following images show the 3D Camera view with the LOW Triangle Count and LOW Terrain Smoothing settings.

 

As you can imagine I'm hesitant to continue if as soon as I increase details settings things break.

 

Am I doing something wrong, what are the rules regarding terrain/contours
( this seems to be a common problem from looking on the forum but I cannot seem to find a definitive summary of the rules )

1. should terrain features and contour lines expanding beyond the terrain perimeter ?
2. should contour lines and elevation regions cross/intersect ?
3. can terrain smoothing help fix this issue?

Any help / advice appreciated as