Calculation of Slope/Passability

[fc14159]

As far as I know, maps are ultimately composed of right isosceles triangles, whose vertices are defined by the heightmap, like this:

square.jpg (16.3 KiB) Viewed 766 times

My question is how slope/passability are calculated. Is a slope defined for each triangle, or each square? Are the slopes calculated from the edges, or the faces?
Note: I need to know this for more than just testing for passability, so please don't tell me to just use tools to see the passability or whatever.

[hoijui]

from rts/ExternalAI/Interface/SSkirmishAICallback.h:

Code: Select all

The values are 1 minus the y-component of the (average) facenormal of the square.