Abstract: A method for simulating motion of cloth or other flexible membranes corrects surface-to-surface intersection involving a membrane. The method may be applied at time intervals of a conventional motion simulation for computer-generated animation. When a collision is detected, a function for a line of intersection between intersecting surfaces is parameterized in terms of vertices of the membrane model. The function is differentiated, and a correction factor is applied to the dynamic simulation in proportion to the value of the partial derivative for respected ones of the intersected vertices. The correction factor may be smoothed over a number of vertices in the vicinity of the intersected vertices.

Abstract: A method for automatically or semi-automatically constructing a digital 3D model of a scene from photographic data and photogrammetry data includes defining an initial rough model as a solution estimate. A reverse rendering step includes a second-order solution method that employs automatic differentiation techniques to accurately compute derivatives of an error function. In an embodiment of the method, at least one camera is placed within the scene being constructed, and photographic data from this camera is used in the solution process.

Abstract: Motion of an articulated figure in response to an external force function and to a co-acting internal force function is simulated, for use in computer animation. The internal force function is defined by applying an inverse-dynamic method to solve for internal forces driving the articulated figure to conform to a predefined animation curve. The internal force function may be scaled in any desired way, an combined with the external force function as input for a forward-dynamics motion simulation. The resulting motion simulation models a combined effect of the external force function and the predefined animation curve on motion of the articulated figure.

Abstract: A method for automatically or semi-automatically constructing a digital 3D model of a scene from photographic data and photogrammetry data includes defining an initial rough model as a solution estimate. A reverse rendering step includes a second-order solution method that employs automatic differentiation techniques to accurately compute derivatives of an error function. In an embodiment of the method, at least one camera is placed within the scene being constructed, and photographic data from this camera is used in the solution process.