4. A computer based system for 3D shape matching and retrieval, comprising: one or more processors; a 3D model repository configured to store a plurality of 3D models; a model processing engine configured to generate representations of a query 3D model and 3D models in the 3D model repository; and a shape retrieval engine configured to retrieve the matching 3D models from the 3D model repository using at least the representation of the query 3D model and representations of the 3D models in the 3D model repository, the shape retrieval engine comprising: a comparator configured to: calculate a first correlation by combining first coefficients associated with the representation of the query 3D model and second coefficients associated with representations of 3D models in the repository to obtain a first output and calculating an inverse rotational Fourier transform of the first output to obtain the first correlation, wherein a number of the first and second coefficients depends on a specified first bandwidth associated with the transform; calculate a first similarity score based on the first correlation; rank one or more 3D models based on the first similarity score; calculating a second correlation by combining third coefficients associated with the representation of the query 3D model and fourth coefficients associated with representations of 3D models in the repository to obtain a second output and calculating an inverse rotational Fourier transform of the second output to obtain the second correlation, wherein a number of the third and fourth coefficients depends on a specified second bandwidth associated with the transform, the second bandwidth being higher than the first bandwidth; calculating, by the one or more processing devices, a second similarity score based on the second correlation; ranking, by the one or more processing devices, the 3D models used in the second correlation based on the second similarity score.
4. A computer based system for 3D shape matching and retrieval, comprising: one or more processors; a 3D model repository configured to store a plurality of 3D models; a model processing engine configured to generate representations of a query 3D model and 3D models in the 3D model repository; and a shape retrieval engine configured to retrieve the matching 3D models from the 3D model repository using at least the representation of the query 3D model and representations of the 3D models in the 3D model repository, the shape retrieval engine comprising: a comparator configured to: calculate a first correlation by combining first coefficients associated with the representation of the query 3D model and second coefficients associated with representations of 3D models in the repository to obtain a first output and calculating an inverse rotational Fourier transform of the first output to obtain the first correlation, wherein a number of the first and second coefficients depends on a specified first bandwidth associated with the transform; calculate a first similarity score based on the first correlation; rank one or more 3D models based on the first similarity score; calculating a second correlation by combining third coefficients associated with the representation of the query 3D model and fourth coefficients associated with representations of 3D models in the repository to obtain a second output and calculating an inverse rotational Fourier transform of the second output to obtain the second correlation, wherein a number of the third and fourth coefficients depends on a specified second bandwidth associated with the transform, the second bandwidth being higher than the first bandwidth; calculating, by the one or more processing devices, a second similarity score based on the second correlation; ranking, by the one or more processing devices, the 3D models used in the second correlation based on the second similarity score. 19. The system of claim 4 , wherein the comparator increases speed of a comparison by performing correlations at smaller resolutions.