The use of version control is pervasive in collaborative software projects. Version control systems are based on two primary operations: diffing two versions to compute the change between them and merging two versions edited concurrently. Recent works provide solutions to diff and merge graphics assets such as images, meshes and scenes. In this work, we present a practical algorithm to diff and merge procedural programs written as node graphs. To obtain more precise diffs, we version the graphs directly rather than their textual representations. Diffing graphs is equivalent to computing the graph edit distance, which is known to be computationally infeasible. Following prior work, we propose an approximate algorithm tailored to our problem domain. We validate the proposed algorithm by applying it both to manual edits and to a large set of randomized modifications of procedural shapes and materials. We compared our method with existing state-of-the-art algorithms, showing that our approach is the only one that reliably detects user edits.

Abstract Procedural materials are extensively used in computer graphics, since they provide editable, resolution‐independent representation of textures. However, tuning the parameters of procedural generators to achieve a desired result remains time‐consuming for users. Recently, inverse procedural material algorithms have been developed, exploiting differentiable rendering methods to find the parameters of a procedural model that match a target image. These approaches focus on raster textures. We propose pOp, a practical method for estimating the parameters of vector patterns, that are formed by collections of vector shapes arranged by an arbitrary procedural program. In our approach, patterns are defined as arbitrary programs, that control the translation, rotation and scale or vector graphics elements. We support elements typical of vector graphics, namely points, lines, circle, rounded rectangles, and quadratic Bèzier drawings, in multiple colors. We optimize the program parameters by automatically differentiating the signed distance field of the drawing, which we found to be significantly more reliable than using differentiable rendering of the final image. We demonstrate our method on a variety of cases, representing the variations found in structured vector patterns.

This work proposes BowlingVR, an advanced Virtual Reality (VR) multiplayer game that tackles two main goals: the first one is to provide a realistic User eXperience (UX) to the user, by reproducing the dynamics and physical context of a real bowling challenge; the second one is to allow a remote, distributed, socially satisfying gameplay, providing the user the illusion of the real presence of the remote players. The prototype was evaluated using a modified version of SUXES, a kind of user interview schema that was originally devised for multimedia applications and that has been modified in order to better compare the responses of different users and get a more reliable estimation of user appreciation.