Hybrid 2D/3D Models for Photo-Based Animations of Virtual Urban Scenes. The Plaza de la Virgen of Valencia, in the 1870s

Abstract

This paper proposes an innovative procedure that takes advantage of the synergies obtained by combining disciplines such as parametric photogrammetry, computer graphics, immersive camera geometry and motion graphics, to achieve advanced visually dynamic scenes from historical isolated images of urban environments. The approach is divided into three stages: generation of a hybrid 2D/3D model, creation of a virtual scenario, and animation by the synchronized movement of an immersive camera. The first stage deals with the geometric aspect, and is the result of a combination of a partial photo-modeling, by means of parameterized 3D primitives, and other 2D layer-segmented elements extracted from the original image. The second stage starts with the recovery of the pinhole camera that took the original image, to create a virtual scenario with the elements of the hybrid model, while the in third, some projective relationships are used to program an animation adapted to the limits of distortion of the 2D background, synchronizing its transformation with the movement of the sub-objects of an immersive camera. A case study is included of a video sequence made as an example of application of the procedure.