A trgeometry can be built directly from its component types, a reference geometry plus a temporal pose:
Construct a temporal rigid geometry from a reference geometry and a temporal pose
trgeometry(geometry,tpose) → trgeometry
SELECT asText(trgeometry(geometry 'Polygon((0 0,1 0,1 1,0 1,0 0))', tpose 'Pose(Point(0 0), 0.0)@2001-01-01')); -- POLYGON((0 0,1 0,1 1,0 1,0 0));Pose(POINT(0 0),0)@2001-01-01
Both arguments must share the same SRID. The reference geometry may be a polygon or a polyhedral surface; the pose may be of any temporal subtype.