pEt: Direct Manipulation of Differentiable Vector Patterns

Eurographics Symposium on Rendering ' - Conference Track
Marzia Riso
Fabio Pellacini
Teaser image
We propose an interactive method to edit the parameters of procedural programs that generate vector patterns, where users interactively transform a set of points and constrain other ones to fixed locations. During the interaction, we solve for the procedural parameters with a gradient-based method since our patterns are differentiable with respect to the procedural parameters for both boundary and interior points. Here we show, for each pattern, the starting, middle and end frames of two sequential edits. We mark in blue the transformed points, in red the fixed ones, and we draw the trajectory of the transformed points in blue in the middle frame.

Abstract

Procedural assets are used in computer graphics applications since variations can be obtained by changing the parameters of the procedural programs. As the number of parameters increases, editing becomes cumbersome as users have to manually navigate a large space of choices. Many methods in the literature have been proposed to estimate parameters from example images, which works well for initial starting points. For precise edits, inverse manipulation approaches let users manipulate the output asset interactively, while the system determines the procedural parameters. In this work, we focus on editing procedural vector patterns, which are collections of vector primitives generated by procedural programs. Recent work has shown how to estimate procedural parameters from example images and sketches, that we complement here by proposing a method for direct manipulation. In our work, users select and interactively transform a set of shape points, while also constraining other selected points. Our method then optimizes for the best pattern parameters using gradient-based optimization of the differentiable procedural functions. We support edits on large variety of patterns with different shapes, symmetries, continuous and discrete parameters, and with or without occlusions.

Video

Citation

@inproceedings{riso23pet, booktitle = {Eurographics Symposium on Rendering}, editor = {Ritschel, Tobias and Weidlich, Andrea}, title = {{pEt: Direct Manipulation of Differentiable Vector Patterns}}, author = {Riso, Marzia and Pellacini, Fabio}, year = {2023}, publisher = {The Eurographics Association}, ISSN = {1727-3463}, ISBN = {978-3-03868-229-5978-3-03868-228-8}, DOI = {10.2312/sr.20231126} }