So using world based normal mapping for rooms, or for other non-dynamic objects but to use tangent based maps for other objects. But what about this problem of the normal map being convex on the reverse side of an object?

Applying the tangent map to a cube for example results (for me at least) with the map being inverted on opposite sides, and completly missing on other faces, when viewed in GS, or the 'other' engine for that matter. Is this a limitation of normal mapping?

As for my reasons for looking at switching back to GS as an engine, rest assured the problems with shaders are only a small part of the reasons. Originally I was approaching this for adding detail to static objects, it was only when I began moving them I noticed the 3D issue. Could the normal map shader not be addapted to cycle through the colours for orientation? I mean if Blue is east as the object rotates the hue does too, so tech you could offset the colour hue based on rotation...although this may be complete rubbish now i read what i have written