SGA: Plug & Play Geometric Verification for Educational Video Synthesis

Jhon Lopez, Carlos Hinojosa, Bernard Ghanem


Abstract
Recent work leverages **Large Language Models (LLMs)** to generate executable code for pedagogical animations using libraries such as **Manim**. However, ensuring spatial correctness and visual legibility remains challenging, as existing frameworks emphasize pedagogical content while overlooking geometric occlusions. We propose the **Symbolic Geometric Agent (SGA)**, a plug-and-play module for code-centric animation pipelines that intercepts LLM-generated code, performs partial execution to extract symbolic scene graphs, and applies targeted refinement when spatial conflicts are detected. We further introduce the **Manim Visual Quality Score (MVQS)**, a deterministic rendering-free proxy for spatial integrity. Experiments on the **MMMC-Code** benchmark across four LLM backbones and two agentic pipelines show that SGA achieves a peak MVQS of **73.11** (**Code2Video + GPT-5.1**), corresponding to a **16.1%** relative improvement over the raw baseline, and improves MVQS in **7 of 8** backbone × pipeline configurations. Additionally, we conduct a human evaluation showing that these improvements translate into human preference, with raters preferring SGA over the raw baseline in **84.4%** of comparisons and over a VLM-based critic in **65.0%**.
Anthology ID:
2026.findings-emnlp.454
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
9533–9549
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.454/
DOI:
Bibkey:
Cite (ACL):
Jhon Lopez, Carlos Hinojosa, and Bernard Ghanem. 2026. SGA: Plug & Play Geometric Verification for Educational Video Synthesis. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 9533–9549, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SGA: Plug & Play Geometric Verification for Educational Video Synthesis (Lopez et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.454.pdf