Generating DEM

Hello all,

I need to have a DEM model for a tilted (dipping) planar surfaces
(for example a surface tilting 45 degrees towards north-east
direction). Is there anyway I can do this in GRASS. I have
tried to look into some of the possible ways of doing this
but haven't been able to figure out how.

Any help/suggestions will be welcome

Thanks in advance.

Venkatesh Raghavan
Osaka City University