FireImpact-Fracture: Unreal Engine-Python framework for interactive thin-shell fracture with flame-induced material weakening

This paper presents FireImpact-Fracture , an interactive thin-shell fracture simulation software framework that integrates fire-induced material degradation history into an impact-driven fracture pipeline. Conventional real-time fracture methods primarily determine crack propagation and fragment generation based on instantaneous impact forces, and often fail to account for the influence of material weakening and shrinkage caused by thermal environments such as fire. To address this limitation, we design a unified pipeline that combines a flame propagation simulation, based on vertex-wise heat diffusion and combustion state transitions, with an impact-driven fracture model. The proposed system consists of a real-time visualization and interaction environment implemented in Unreal Engine and a Python-based fracture computation module connected via TCP communication. During the flame simulation stage, the temperature, fuel consumption, and combustion state of each vertex are tracked and summarized into a vertex-wise material weight representing local material strength. When an impact occurs, these weights are used to modulate fracture sensitivity, guiding crack initiation and propagation along thermally weakened regions. As a result, asymmetric and multi-scale fracture patterns emerge under identical impact conditions, depending on the prior fire exposure history. The framework is designed to reflect fire-induced damage in a stable and intuitive manner without requiring expensive thermo-mechanical analysis. Experimental results demonstrate that thermally guided fracture behaviors, which are difficult to reproduce using impact-only models, can be generated in real time. The proposed software provides a practical tool for game-engine-based environment destruction, fire disaster simulation, and interactive content production.