To make it clear, the whole tranlation can be described as follows:
(1)world coordinate(unscaled)<->(2)world coordinate, but self.origin is the origin(unscaled)<->(3)sdf grid coordinate(scaled)
(3) to (2) is simply a scale transformation(multiplied by the scale factor, a.k.a. self.resolution), (2) to (1) is a translation(added by self.origin).
self.T_grid_sdf_ try to establish a tranform from (3) to (1). Since in autolab_core==0.0.4, SimilarityTransform is a two-step process begin with scale then rotation/translation(code). We should use an unscaled translation here, which means that the self.origin should not be divided by self.resolution.