Let's break it down.TerrMesh
SPEC FALSE
NBL 2 3
TMS 170.14 161.48
CBE 0.00 170.23 46 112 10 194 169 92
BLO 0.00 L 1 194 169 92 1 46 112 10
BLO 0.00 R 1 194 169 92 1 46 112 10
BLO 0.00
BLO 0.00 R 1 194 169 92 1 194 169 92
BLO 212.78 R 1 194 169 92 1 194 169 92
BLO 0.00
BLO 0.00 R 1 46 112 10 1 194 169 92
BLO 212.78 L 1 46 112 10 1 194 169 92
BLO 0.00
BLO 0.00
BLO 0.00
BLO 0.00
END
TerrMesh defines the filetype (similar to the DYNAMODEL header in .dnm and SURF in .srf)
SPEC FALSE or SPEC TRUE disable or enable specular reflections (currently found only in the OpenGl2 version).
NBL # # defines the number of columns and rows the elevation grid has.
TMS defines the square dimensions, and so is grid length and width divided by NBL.
See below for CBE.
The BLO lines come in blocks. Each block has as many lines as NBL # #, and there are as many blocks as NBL # #. Blocks are ended by BLO 0.00, which defines the last (faceless) node on the line. The last block is made up of only node lines (being the final edge of the grid, there are no faces to associate with the nodes).
BLO 0.00 R 1 0 127 0 0 0 127 0
Part of the grid
Node height(m)
Left or right face orientation (from Elevation Grid > Flip Selected Faces)
Face state: invisible (0), visible (1), projected picture flag (2), or protected face (3)
Face colour
The CBE line defines the gradient.
The gradient is calculated when applied in Scenedit, and colours the individual faces, then smooths them. It won't recolour if elevations are changed, so it's possible to get the peak colour on the side of a mountain if you change the geometry without updating the gradient.
CBE 0.00 170.23 46 112 10 194 169 92
Zero
80% of maximum height when the gradient is calculated. These two don't currently do anything, but may eventually be for changing gradient distribution.
Foot colour
Peak colour
As usual, the file ends with END.