We present a patch-based terrain synthesis framework constrained by user-specified curvilinear features such as ridges and valleys. A user specifies where terrain features appear in the generated terrain by providing a 2D sketch map or drawing 2.5D sketched curves in the sketching interface. A novel patch merging technique is proposed to remove boundary artifacts created by overlapping patches.
We present a crowd simulation behavioural model for simulating identified crowd phenomena in a virtual city such as street flows, crowd formation and road crossings. We propose a three-tier architecture model to produce intentions, perform path planning and control movement. We demonstrate that this model produces the desired behaviour associated with pedestrian navigation in a virtual city, which includes navigation, flow formation, circle creation and passageway crossing.