Reconstructing or repairing the damaged or diseased tissues with porous scaffolds to restore the mechanical, biological and chemical functions is one of the major tissue engineering strategies. Development of Solid Free Form (SFF) techniques and improvement in biomaterial properties by synergy have provided the leverage to fabricate controlled and interconnected porous scaffold structures. But homogeneous scaffolds with regular porosity do not provide all the biological and mechanical requirements of an ideal tissue scaffold. Thus achieving controllable, continuous, interconnected gradient porosity with reproducible and fabricatable design is critical for successful regeneration of the replaced tissue. In this research, a novel scaffold modeling approach has been proposed to achieve bio-mimetic tissue scaffolds. Firstly, the optimum filament deposition angle has been determined based on the internal heterogeneous regions and their locations. Then an area-weight based approach has been applied to generate the spatial porosity function to determine the filament deposition location for the desired bio-mimetic porosity. The proposed methodology has been implemented using computer simulation. A micro-nozzle biomaterial deposition system driven by NC motion control has been used to fabricate a sample designed structure