Local Editing of Procedural Models

Abstract

Procedural modeling is used across many industries for rapid 3D content creation. However, professional procedural tools often lack artistic control, requiring manual edits on baked results, diminishing the advantages of a procedural modeling pipeline. Previous approaches to enable local artistic control require special annotations of the procedural system and manual exploration of potential edit locations. Therefore, we propose a novel approach to discover meaningful and non‐redundant good edit locations (GELs). We introduce a bottom‐up algorithm for finding GELs directly from the attributes in procedural models, without special annotations. To make attribute edits at GELs persistent, we analyze their local spatial context and construct a meta‐locator to uniquely specify their structure. Meta‐locators are calculated independently per attribute, making them robust against changes in the procedural system. Functions on meta‐locators enable intuitive and robust multi‐selections. Finally, we introduce an algorithm to transfer meta‐locators to a different procedural model. We show that our approach greatly simplifies the exploration of the local edit space, and we demonstrate its usefulness in a user study and multiple real‐world examples.

Differentiable 3D CAD Programs for Bidirectional Editing

“…many approaches on inverse procedural modeling target program generation from input specifications [TLL*11; VGA*12; GJB*20], but do not allow direct editing. While there is some work on local editing from program analysis [JPCS18; LSL*19], none of these methods allow users to control geometric edits directly while maintaining a working program. In concurrent work to ours, Gaillard et al [GKG*22] enable direct editing at the granularity of objects, and directly tackle exploring ambiguous edits made possible in part by a fast objective function.…”

Automatic Differentiable Procedural Modeling

“…While these methods allow for some control of the procedural generation, the edits are still indirect. In contrast, Lipp et al [LSL ∗ 19] showed a method that can automatically generate handles for “good edit locations”, enabling direct local editing of architectural, procedural models. Our method is similar in that it allows direct local edits.…”

DAG amendment for inverse control of parametric shapes

“…[Barroso et al 2013] proposes to rewrite the rule set of a shape grammar (which may also be represented as a DAG as shown by [Patow 2012]). [Lipp et al 2019] transforms edits applied by the user on a particular instance of a generator into edits of the program that generates a procedural shape. [Lienhard et al 2017] proposes automatic grammar rewriting, thus synthesizing programs that are the interpolation of other input programs.…”